1. A communication node that communicates with a user device over a wireless interface, the communication node comprising: 5 transceiver circuitry that transmits signals to and receives signals from the user device using a sequence of sub-frames, each sub-frame comprising a plurality of colnmunication resource blocks, each resource block corresponding to a sub-band of a system bandwidth used by the communication node to communicate with the user device and each resource block having a control portion for carrying first control data and a data portion for carrying user data; and 10 a resource allocatioil module arranged to allocate, within a sub-frame, resource blocks for communicating with the user device; wherein the resource allocation module is arranged: i) to generate first resource allocation data for transmission to the user device, which first resource allocation data allocates a first plurality of the resource blocks for use in communicating user data with the user device; ii) to 15 allocate at least one resource block for carrying second control data for the user device within the data portion of the at least one resource block, which at least one resource block is included within said first plurality of resource blocks allocated by said first resource allocation data; and iii) to generate second resource allocation data for transmission to the user device that the user device can use to exclude the at least one resource block carrying said second control data from 20 the first plurality of resource blocks allocated by said first allocation data.

2. A comlnunication node according to claim 1, wherein said second resource allocation data identifies the at least one resource block for carrying second control data in combination with the first resource allocation data. 2 5

3. A communication node according to claim 1 or 2, wherein said second resource allocation data identifies the at least one resource block for carrying second control data relative to the first plurality of resource blocks allocated by said first resource allocation data. 30 4. A colnmunication node according to any of claims 1 to 3, wherein the plurality of resource blocks of a sub-frame are arranged in a sequence of resource block groups and wherein said first resource allocation data allocates the resource blocks within a selected one or more of said resource block groups.

5. A communication node according to claim 4, wherein the second resource allocation data comprises a bitmap, wherein the bits within the bitmap correspond to resource blocks within the selected one or more resource block groups and identify said at least one resource block for carrying said second control data. 5

6. A communication node according to any of claims 1 to 5, wherein the first allocation data is arranged to allocate said first plurality of resource blocks as a contiguous group of resource blocks. 10 7. A communication node according to any of claims 1 to 6, wherein the first allocation data comprises at least one of: i) a bit map identifying the first plurality of allocated resource blocks, and ii) data identifying a starting resource block and a number of resource blocks from the starting resource block that are allocated. 15 8. A communication node according to any of claims 1 to 7, wherein the at least one resource block is allocated within a known subset of the resource blocks and wherein the second resource allocation data identifies the at least one resource block with reference to the known subset. 20 9. A communication node according to claim 8, comprising means for transmitting third control data to the user device that identifies the subset of resource blocks.

10. A communicatioll node according to claim 9, wherein said means for transmitting is arranged to transmit the third co~itrodl ata in advance of the communication node transmitting 25 the sub-frame.

11. A communicatioll node according to claim 9, wherein said means for transmitting is arranged to tra~lsmith e third control data within the sub-frame. 30 12. A communication node according to any of claims 8 to 11, wherein the known subset of resource blocks is arranged to change from sub-frame to sub-frame.

13. A communication node according to any of claims 1 to 7, wherein the at least one resource block is allocated within one of a plurality of predefined subsets of resource blocks and wherein the second resource allocation data identifies one or more of the predefined subsets of resource blocks containing second control data for exclusion from said plurality of resource blocks allocated by said first allocation data. 5 14. A com~nuilicationn ode according to claim 13, wherein each predefined subset of resource blocks has an associated index value and wherein the second control data identifies the index value associated with the one or more of the predefined subsets of resource blocks containing second control data. 10 15. A communication node according to any of claims 1 to 14, operable to commuilicate with a plurality of user devices using said resource bocks and operable to transmit respective second control data to each user device individually.

16. A communication node according to any of claims 1 to 14, operable to communicate with 15 a plurality of user devices using said resource bocks and operable to broadcast second control data for all user devices collectively.

17. A con~municationn ode according to claim 15, wherein different second control data is transmitted to the user devices. 20

18. A communication node according to claim 17, wherein the resource allocation module is operable to generate respective first allocation data for first and second user devices that define overlapping resource blocks that are allocated for the first and second user devices and wherein the resource allocation module is operable to generate different second control data for the first 25 and second user devices to cause each user device to exclude resource blocks to remove the overlap.

19. A communication node according to any of claims 1 to 18, wherein the first and second allocation data is transmitted within an enhanced Physical Dowllliilk Control Channel, ePDCCH. 3 0

20. A con~municationn ode according to any of claims 1 to 19, wherein the resource allocation module is operable to generate first allocatioll data that allocates virtual resource blocks. 2 1. A user device for communicating with a commui~ication node, the user device comprising: transceiver circuitry that transinits signals to and receives signals from the communication node using a sequence of sub-fiames, each sub-frame comprising a plurality of 5 communication resource blocks, each resource block corresponding to a sub-band of a system bandwidth of the communication node and each resource block having a control portion for carrying first control data and a data portion for carrying user data; and a communication control module tliat is arranged: i) to receive first resource allocation data, which first resource allocation data allocates a first plurality of the resource blocks for use 10 in communicating user data with the communication node; ii) to receive at least one resource block that carries second control data for the user device within the data portion of the at least one resource block, which at least one resource block is included within said first plurality of resource blocks allocated by said first resource allocation data; iii) to receive second resource allocation data relating to the at least one resource block carrying said second control data; and 15 iv) to exclude the at least one resource block carrying said second control data from the first plurality of resource blocks allocated by said first allocation data.

22. A user device according to claim 2 1, wherein said communication control module is arranged to use the second resource allocation data in combinatioli with the first resource 20 allocation data to identify the at least one resource block that carries the second control data.

23. A user device according to claim 21 or 22, wherein said second resource allocation data identifies the at least one resource block that carries tlie second control data relative to the first plurality of resource blocks allocated by said first resource allocation data. 2 5

24. A user device according to any of clai~ns2 1 to 23, wherein the plurality of resource bloclcs of a sub-frame are arranged in a sequence of resource block groups and wherein said first resource allocation data allocates tlie resource blocks within a selected one or more of said resource block groups. 3 0

25. A user device according to claim 24, wherein the second resource allocation data comprises a bitmap, wherein the bits within the bitlnap correspond to resource blocks within the selected one or more resource block groups and identify said at least one resource bloclc for carrying said second control data.

26. A user device according to any of claims 21 to 25, wherein the first allocation data allocates said first plurality of resource blocks as a contiguous group of resource blocks. 5 27. A user device according to ally of claims 21 to 26, wherein the first allocation data comprises at least one of: i) a bit map identifying the first plurality of allocated resource blocks, and ii) data identifying a starting resource block and a number of resource blocks from the starting resource block that are allocated. 10 28. A user device according to any of claims 21 to 27, wherein the at least one resource block is allocated within a predefined subset of the resource blocks and wherein the second resource allocation data identifies the at least one resource block with reference to the predefined subset. 15 29. A user device according to claim 28, comprising means for receiving third control data that identifies the predefined subset of resource blocks.

30. A user device according to claim 29, wherein said means for receiving is arranged to receive the third control data in advance of the user device receiving the sub-frame. 2 0 3 1. A user device according to claim 29, wherein said means for receiving is al-sanged to receive the third control data within the sub-frame.

32. A user device according to any of claims 28 to 3 1, wherein the predefined subset of 25 resource blocks is arranged to change from sub-frame to sub-frame.

33. A user device according to any of claims 21 to 27, wherein the at least one resource block is allocated within one of a plurality of predefined subsets of resource blocks and wherein the second resource allocation data identifies one or more of the predefined subsets of resource 30 blocks containing second control data and wherein the commullication colltrol module is arranged to exclude the resource blocks within the identified predefined subsets from the plurality of resource blocks allocated by the first allocatioli data.

34. A user device according to claim 33, wherein each predefined subset of resource blocks has an associated index value and wherein the second control data identifies the index value associated with the one or more of the predefined subsets of resource blocks containing second control data. 5 35. A user device according to any of claims 1 to 18, wherein the first and second allocation data is transmitted within an enhanced Physical Downlink Control Channel, ePDCCH.

36. A method performed within a communication node that communicates with a user device over a wireless interface, the method comprising: 10 transmitting signals to and receiving signals from the user device using a sequence of sub-frames, each sub-frame comprising a plurality of communication resource blocks, each resource block corresponding to a sub-band of a system bandwidth used by the communication node to communicate with the user device and each resource block having a control portion for carrying first control data and a data portion for carrying user data; and allocating, within a sub-frame, resource blocks for communicating with the user device; wherein the allocating step comprises: i) generating first resource allocation data for transmission to the user device, which first resource allocation data allocates a first plurality of the resource blocks for use in communicating user data with the user device; ii) allocating at least one resource block for carrying second control data for the user device within the data 20 portion of the at least one resource block, which at least one resource block is included within said first plurality of resource blocks allocated by said first resource allocation data; and iii) generating second resource allocation data for transmission to the user device that the user device can use to exclude the at least one resource block carrying said second control data from the first plurality of resource blocks allocated by said first allocation data. 2 5

37. A method according to claim 36, performed by a comnluliicatioil nodc accordiilg to any of claims 1 to 20.

38. A method performed by a user device that communicates with a communication node, 30 the method comprising: transmits signals to and receiving signals from the commurlication node using a sequence of sub-frames, each sub-frame comprising a plurality of communication resource blocks, each resource block corresponding to a sub-band of a system bandwidth used by the user device to communicate with the communication node and each resource block having a control portion for carrying first control data and a data portion for carrying user data; and controlling the communication, including: i) receiving first resource allocation data, which first resource allocation data allocates a first plurality of the resource blocks for use in communicating user data with the communication node; ii) receiving at least one resource block 5 that carries second control data for the user device within the data portion of the at least one resource block, which at least one resource block is included within said first plurality of resource blocks allocated by said first resource allocation data; iii) receiving second resource allocation data relating to the at least one resource block carrying said second control data; and iv) excluding the at least one resource block carrying said second control data from the first 10 plurality of resource blocks allocated by said first allocation data.

39. A method according to claim 38, performed by a user device according to any of claims 21 to 35. 15 40. A communication node that communicates with a user device over a wireless interface, the communication node comprising: transceiver circuitry that transmits signals to and receives signals from the user device using a sequence of sub-frames, each sub-frame comprising a plurality of communication resource blocks, each resource block correspondiilg to a sub-band of a system bandwidth used by 20 the communication node to communicate with the user device; a communications control module for controlling communications with the user device and arranged to send control data to the user device in one of a plurality of predefined control data formats, the control data formats including a plurality of legacy control data formats each comprising a different number of bits and one or more new control data formats that each have 25 the same number of bits as a legacy control data format; and a resource allocation module arranged to generate resource allocation data that allocates, within a sub-frame, resource bloclcs for communicating with the user device; wherein the communications control module is arranged to include the resource allocation data within a selected one of the predefined control data formats and in the case that 30 the resource allocation data has been included within a control data format that has the same number of bits as another control data format, is arranged to signal additional control data to the user device to indicate which control data format has been signalled.

41. A communication node according to claim 40, wherein the coinmunication control module is arranged to signal the additional control data to the user device within the control data format.

42. A communication node according to claim 40, wherein the communication colltrol 5 module is arranged to signal the additional control data to the user device within another different control data format.

43. A comlnunication node according to any of claims 40 to 42, wherein the resource allocation data of a first legacy control data format includes: a field that is used to indicate a selected resource block group subset froin among a plurality of resource block group subsets; and a field that includes a bitmap, where each bit of the bitmap addresses a single resource block in the selected resource block group subset; wherein the resource allocation data of a first new control data format has the same 15 number of bits as the first legacy coiltrol data format and includes: a field that is used to indicate a selection of one out of K partitions of a system bandwidth of the communication node, where each bandwidth part contains contiguous resource blocks; and a field that includes a bitmap, where each bit of the bitmap addresses a single resource block in the selected bandwidth part and indicates if the addressed resource block is allocated to 20 the user device.

44. A communication node according to any of claims 40 to 42, wherein the resource allocatiol~d ata of a first legacy control data format includes: a field that is used to indicate a selected resource block group subset from among a 25 plurality of resource block group subsets; and a field that includes a bitmap, where each bit of the bitmap addresses a single resource block in the selected resource block group subset; wherein the resource allocation data of a first new control data format has the same number of bits as the first legacy control data format and includes: 3 0 a field that is used to indicate a starting resource block of a partition of resource blocks within a systein bandwidth of the communication node; and a lield that includes a bitmap, where each bit of the bitmap addresses a single resource block in the partition of rcsource blocks and indicates if the resourcc block is allocated to the user device.

45. A coininuilication node according to claim 44, wherein the field used to indicate a stai-ting resource block of the first new control data format comprises I"~~(NRI ub)i ts and the field of the first new control data field that includes the bitinap conlprises Gm '1 - r10g2(NRU)l 5 bits, where NRB is the number of available resource blocks and P defines the number of resource blocks within each subset.

46. A communication node according to claim 44, wherein the Geld used to indicate a starting resource block of the first new control data format comprises I"~z(NRB1 )b its and the 10 field of the first new control data field that includes the bitmap comprises lNRB'l bits, where NRB is the number of available resource blocks and P defines the number of resource blocks within each subset.

47. A communication node according to claim 43 or 44, wherein the first legacy control data 15 format and the first new control data format further includes a field that indicates if the control data field is the first legacy control data format or the first new control data format.

48. A user device that communicates with a comnluilication node over a wireless interface, the user device comprising: 2 0 transceiver circuitry that transmits signals to and receives signals from the communication node using a sequence of sub-frames, each sub-frame comprising a plurality of conlmunication resource blocks, each resource block corresponding to a sub-band of a system bandwidth of the communication node; a communications control module for controlling cominunications with the 25 cominunicatiorl node and operable: i) to receive control data from the communication node in one of a plurality of predefined coiltrol data formats, the control data formats including a plurality of legacy control data formats each comprising a different number of bits and one or nlore new control data formats that each have the same number of bits as a legacy control data format, the received 30 coiltrol data comprising resource allocation data that allocates, within a sub-frame, resource blocks for communicating with the communication node; ii) in the case that the received control data is ill a coiltrol data for~natth at has the same number of bits as another control data format, to receive additional control data that indicates which control data format has been used; and a control data interpreter module that interprets the received control data format in accordance with the legacy control data format or in accordance with the new coiltrol data format 5 in dependence upon the received additional control data.

49. A user device according to claim 48, wherein the communication control module is arranged to receive the additional control data within the control data format. 10 50. A user device according to clai~n4 8, wherein the communication control module is arranged to receive the additional control data within another different control data format. 5 1. A user device according to any of claims 48 to 50, wherein the resource allocatioi~d ata of a first legacy control data format includes: 15 a field that is used to indicate a selected resource block group subset from among a plurality of resource block group subsets; and a field that includes a bitmap, where each bit of the bitmap addresses a single resource block in the selected resource block group subset; wherein the resource allocation data of a first new control data format has the same 20 number of bits as the first legacy control data format and includes: a field that is used to indicate a selection of one out of K partitions of a system bandwidth of the communication node, where each bandwidth part contains contiguous resource blocks; and a field that includes a bitmap, where each bit of the bitmap addresses a single resource block in the selected bandwidth pal? and indicates if the addressed resource block is allocated to 25 the user device.

52. A user device according to any of claims 48 to 50, wherein the resource allocation data of a first legacy control data format includes: a field that is used to indicate a selected resource block group subset from among a 30 plurality of resource block group subsets; and a field that includes a bitmap, where each bit of the bitmap addresses a single resource block in the selected resource block group subset; wherein the resource allocation data of a first new control data format has the same number of bits as the first legacy control data format and includes: a field that is used to indicate a starting resource block of a partition of resource blocks within a system bandwidth of the communication node; and a field that includes a bitmap, where each bit of the bitmap addresses a single resource block in the partition of resource blocks and indicates if the resource block is allocated to the 5 user device.

53. A user device according to claim 52, wherein the field used to indicate a starting resource block of the first new control data format comprises I ' o ~ ~ ( ~ , B ) 1 bits and the field of the first new control data field that includes the bitmap comprises rNRB p1 -r10g2(NRB1) bits, where NRB is the 10 number of available resource blocks and P defines the number of resource blocks within each subset.

54. A user device according to claim 52, wherein the field used to indicate a starting resource block of the first new control data format comprises 1 l o " ( ~ ~ ~1 )b its and the field of the first new 15 control data field that includes the bitmap comprises IN' bits, where NRB is the number of available resource blocks and P defines the number of resource blocks within each subset.

55. A user device according to claim 5 1 or 52, wherein the first legacy control data format and the first new control data format further includes a field that indicates if the control data field 20 is the first legacy control data format or the first new control data format.

56. A computer instruction product comprising computer implementable instructions for causiilg a progralnlnable communication device to become configured as a colllmunication node according to ally of claims 1 to 20 or 40 to 47 or for causing a programmable user device to 25 become configured as the user device of any of claims 21 to 35 or 48 to 55.

Title of Invention:
RESOURCE ALLOCATION SIGNALLING
5
Technical Field:
The present invention relates to control signalling for the allocation of resources within a
communication system. The invention has particular, although not exclusive relevance to the
efficient allocation of resources used to signal the allocation of physical resource blocks (PRBs)
10 for downlink and/or uplink user data communications in a Long Term Evolution (LTE) of
UTRAN (UMTS Terrestrial Radio Access Network) system.
Background Art:
In an LTE communication system, in order for a user device to transmit and receive data
15 over the air interface, the user device needs to be allocated physical radio resources, and the user
device must be notified of its resource assignments by means of control signalling. In LTE, the
physical downlink control channel (PDCCH) carries scheduling assignments and other control
information, and the PDCCH resources used to signal scheduling assignments to users in the cell
are dynamically allocated by the serving base station.
2 0 A PDCCH consists of an aggregation of one or more consecutive control channel
elements (CCEs), where a CCE occupies a fraction of the base station cell's available physical
radio resources. The total number of CCEs available in a cell depends on the system bandwidth
of the cell and the number of OFDM symbols reserved for PDCCFI transmission in a given subframe.
Typically, the first three symbols of a sub-frame are reserved for the PDCCII. With LTE
25 Release 11 and beyond additional control channel information can be included using radio
resources usually assigned for the Physical Downlink Shared Channel (PDSCH). One example
of such additional control channel information is called the enhanced PDCCH (ePDCCH).
However, the provision of an ePDCCH in the PDSCH causes problems for the efficient
allocation of resources within the PDSCII (as it results in the fragmentation of resources that are
30 allocated) and additional resource allocation techniques are required to address these
inefficiencies.
Disclosure of Invention:
According to one aspect, the present invention provides a coininunication node that
coinmunicates with a user device over a wireless interface, the communication node comprising:
transceiver circuitry that transmits signals to and receives signals from the user device using a
sequence of sub-frames, each sub-frame comprising a plurality of communication resource
blocks, each resource block corresponding to a sub-band of a system bandwidth used by the
5 communication node to communicate with the user device and each resource block having a
control portion for carrying first control data and a data portion for carrying user data; and a
resource allocation module arranged to allocate, within a sub-frame, resource blocks for
communicating with the user device; wherein the resource allocation module is arranged: i) to
generate first resource allocation data for transmission to the user device, which first resource
10 allocation data allocates a first plurality of the resource blocks for use in communicating user
data with the user device; ii) to allocate at least one resource block for carrying second control
data for the user device within the data portion of the at least one resource block, which at least
one resource block is included within said first plurality of resource blocks allocated by said first
resource allocation data; and iii) to generate second resource allocation data for transmission to
15 the user device that the user device can use to exclude the at least one resource block carrying
said second control data from the first plurality of resource blocks allocated by said first
allocation data.
The second resource allocation data in combination with the first resource allocation data
may identify the at least one resource block that carries the second control data.
2 0 The second resource allocation data may identify the at least one resource block for
carrying second control data relative to the first plurality of resource blocks allocated by said
first resource allocation data.
The plurality of resource blocks of a sub-frame may be arranged in a sequence of
resource block groups and the first resource allocation data may allocate the resource blocks
25 within a selected one or more of said resource block groups. I this case, the second resource
allocation data may comprise a bitmap, wherein the bits within the bitmap correspond to
resource blocks within the selected one or more resource block groups and identify said at least
one resource block for carrying said second control data.
The first allocation data may comprises at least one of: i) a bit map identifying the first
30 plurality of allocated resource blocks, and ii) data identifying a starting resource block and a
number of resource blocks from the starting resource block that are allocated.
The at least one resource block may be allocated within a known subset of the resource
blocks and the second resource allocation data may identify the at least one resource block with
reference to the known subset.
Means, such as the transceiver circuitry, may be provided for transmitting third control
data to the user device that identifies the subset of resource blocks. This means for transmitting
may transmit the third control data in advance of the communication node transmitting the subframe
or it may transmit the third control data within the sub-frame. The known subset of
5 resource blocks may be fixed or it may change from sub-frame to sub-fiame.
In an alternative embodiment, the at least one resource block is allocated within one of a
plurality of predefined subsets of resource blocks and the second resource allocation data
identifies one or more of the predefined subsets of resource blocks containing second control
data for exclusion from said plurality of resource blocks allocated by said first allocation data. In
10 this case, each predefined subset of resource blocks may have an associated index value and the
second control data identifies the index value associated with the one or more of the predefined
subsets of resource blocks containing second control data.
Typically, the communication node will communicate with a plurality of user devices
using the resource bocks in a sub-frame and will transmit respective second control data to each
15 user device individually or collectively. If the second control data is transmitted individually to
each user device, then different second control data can be transmitted to each user device. In
this case, the resource allocation module may generate respective first allocation data for first
and second user devices that define overlapping resource blocks that are allocated for the first
and second user devices and the resource allocation module may generate different second
20 control data for the first and second user devices to cause each user device to exclude resource
blocks to remove the overlap.
The first and second allocation data may be transmitted within an enhanced Physical
Downlink Control Channel, ePDCCH.
The resource allocation module may allocate physical resource blocks or virtual resource
25 blocks.
The invention also provides a user device for communicating with a communication
node, the user device comprising: transceiver circuitry that transmits signals to and receives
signals from the cominunication node using a sequence of sub-frames, each sub-frame
comprising a plurality of cominunicatioil resource blocks, each resource block corresponding to
30 a sub-band of a system bandwidth of the communication node and each resource block having a
control portion for carrying first control data and a data portion for carrying user data; and a
colnmullication control module that is arranged: i) to receive first resource allocation data, which
first resource allocation data allocates a first plurality of the resource blocks for use in
coinmunicating user data with the cominunication node; ii) to receive at least one resource block
that carries second control data for the user device within the data portion of the at least one
resource block, which at least one resource block is included within said first plurality of
resource blocks allocated by said first resource allocation data; iii) to receive second resource
allocation data relating to the at least one resource block carrying said second control data; and
5 iv) to exclude the at least one resource block carrying said second control data from the first
plurality of resource blocks allocated by said first allocation data.
The communication control module may be arranged to use the second resource
allocation data in combination with the first resource allocation data to identify the at least one
resource block that carries the second control data.
10 The second resource allocation data may identify the at least one resource block that
carries the second control data relative to the first plurality of resource blocks allocated by said
first resource allocation data.
The plurality of resource blocks of a sub-frame may be arranged in a sequence of
resource block groups and the first resource allocation data may allocate the resource blocks
15 within a selected one or more of said resource block groups. In this case, the second resource
allocation data may comprise a bitmap, wherein the bits within the bitmap correspond to
resource blocks within the selected one or more resource block groups and identify said at least
one resource block for carrying said second control data.
The first allocation data may allocate said first plurality of resource blocks as a
20 contiguous group of resource blocks, although this is not essential.
The first allocation data may comprises at least one of: i) a bit map identifying the first
plurality of allocated resource blocks, and ii) data identifying a starting resource block and a
number of resource blocks from the starting resource block that are allocated.
The at least one resource block may be allocated within a predefined subset of the
25 resource blocks and the second resource allocation data may identifies the at least one resource
block with reference to the predefined subset. In this case, means for receiving third control data
that identifies the predefined subset of resource blocks may be provided. This means for
receiving may be arranged to receive the third control data in advance of the user device
receiving the sub-frame or it may receive the third control data within the sub-frame.
3 0 The predefined subset of resource blocks inay be static or it may change from sub-fsarne
to sub-frame.
In an alternative embodiment, the at least one resource block inay be allocated within one
of a plurality of predefined subsets of resource blocks and the second resource allocation data
identifies one or more of the predefined subsets of resource blocks containing second control
data and the communication control module is arranged to exclude the resource blocks within the
identified predefined subsets from the plurality of resource blocks allocated by the first
allocation data. In this case, each predefined subset of resource blocks may have an associated
index value and the second co~ltrodl ata identifies the index value associated with the one or
5 more of the predefined subsets of resource blocks containing second control data.
The first and second allocation data may be transmitted within an enhanced Physical
Downlink Control Channel, ePDCCH.
The invention also provides a method performed within a communication node that
communicates with a user device over a wireless interface, the method comprising: transmitting
10 signals to and receiving signals from the user device using a sequence of sub-frames, each subframe
comprising a plurality of communication resource blocks, each resource block
co~~espondintog a sub-band of a system bandwidth used by the communication node to
communicate with the user device and each resource block having a control portion for carrying
first control data and a data portion for carrying user data; and allocating, within a sub-frame,
15 resource blocks for communicating with the user device; wherein the allocating step comprises:
i) generating first resource allocation data for transmission to the user device, which first
resource allocation data allocates a first plurality of the resource blocks for use in
communicating user data with the user device; ii) allocating at least one resource block for
cai-sying second control data for the user device within the data portion of the at least one
20 resource block, which at least one resource block is included within said first plurality of
resource blocks allocated by said first resource allocation data; and iii) generating second
resource allocation data for transmission to the user device that the user device can use to
exclude the at least one resource block carrying said second control data from the first plurality
of resource blocks allocated by said first allocation data.
2 5 The invention also provides a method performed by a user device that communicates
with a communication node, the method comprising: transmitting signals to and receiving signals
from the communication node using a sequence of sub-frames, cach sub-frame comprising a
plurality of conlmunication resource blocks, each resource block corresponding to a sub-band of
a system bandwidth used by the user device to communicate with the comm~ulication node and
30 each resource block having a control portion for carrying first control data and a data portion for
carrying user data; and controlling the communication, including: i) receiving first resource
allocation data, wllicll first resource allocation data allocates a first plurality of the resource
blocks for use in communicating user data with the colnrnunication node; ii) receiving at least
one resource block that carries second control data for the user device within the data portion of
the at least one resource block, which at least one resource block is included within said first
plurality of resource blocks allocated by said first resource allocation data; iii) receiving second
resource allocation data relating to the at least one resource block carrying said second control
data; and iv) excluding the at least one resource block carrying said second control data from the
5 first plurality of resource blocks allocated by said first allocation data.
According to another aspect, the invention also provides a communication node that
communicates with a user device over a wireless interface, the communication node comprising:
transceiver circuitry that transmits signals to and receives signals from the user device using a
sequence of sub-frames, each sub-frame comprising a plurality of communication resource
10 blocks, each resource block corresponding to a sub-band of a system bandwidth used by the
communication node to communicate with the user device; a communications control module for
controlling communications with the user device and axranged to send control data to the user
device in one of a plurality of predefined control data formats, the control data formats including
a plurality of legacy control data formats each comprising a different number of bits and one or
15 more new control data formats that each have the same number of bits as a legacy control data
format; and a resource allocation module arranged to generate resource allocation data that
allocates, within a sub-frame, resource blocks for communicating with the user device; wherein
the communications control module is arranged to include the resource allocation data within a
selected one of the predefined control data formats and in the case that the resource allocation
20 data has been included within a control data format that has the same number of bits as another
control data format, is arranged to signal additional control data to the user device to indicate
which control data format has been signalled.
The communication control module nlay be arranged to signal the additional control data
to the user device within the control data format or within another different control data format.
The resource allocation data of a first legacy control data format may include:
a field that is used to indicate a selected resource block group subset from among a
plurality of resource block group subsets; and
a field that includes a bitmap, where each bit of the bitmap addresses a single resource
block in the selected resource block group subset.
3 0 The resource allocation data of a first new control data format may have the same number
of bits as the first legacy control data for~naat nd may include:
a field that is used to indicate a selection of one out of K partitions of a system bandwidth
of the co~nmunicationn ode, where each bandwidth part contains contiguous resource blocks; and
a field that includes a bitmap, where each bit of the bitlnap addresses a single resource
block in the selected bandwidth past and indicates if the addressed resource block is allocated to
the user device.
Alternatively, the resource allocation data of a first legacy control data format includes:
a field that is used to indicate a selected resource block group subset from among a
5 plurality of resource block group subsets; and
a field that includes a bitmap, where each bit of the bitmap addresses a single resource
block in the selected resource block group subset.
The resource allocation data of a first new control data format has the same number of
bits as the first legacy control data format and includes:
10 a field that is used to indicate a starting resource block of a pastition of resource blocks
within a system bandwidth of the communication node; and
a field that includes a bitmap, where each bit of the bitmap addresses a single resource
block in the partition of resource blocks and indicates if the resource block is allocated to the
user device.
In this case, the field used to indicate a starting resource block of the first new control
data format may comprise 1 ' ' ~ z ( ~ R B ) I bits and the field of the first new control data field that
1 includes the bitmap may comprise rNRB i p l r ' o g 2 ( N R B ) bits, where NRB is the number of
available resource blocks and P defines the number of resource blocks within each subset.
Alternatively, the field used to indicate a starting resource block of the first new control
20 data format may comprise I " ~ ~ ( N R B ) 1 bits and the field of the first new control data field that
includes the bitmap may comprise rNRB bits, where NRB is the number of available resource
blocks and P defines the number of resource blocks within each subset.
The first legacy control data format and the first new control data format may further
include a field that indicates if the control data field is the first legacy control data format or the
25 first new control data format.
This aspect of the invention also provides a user device that colnmunicates with a
communication node over a wireless interface, the user device comprising: tra~lsceiverc ircuitry
that tra~lsmitss ignals to and receives signals from the communication node using a sequence of
sub-frames, each sub-frame comprising a plurality of co~nmunicationr esource blocks, each
30 resource block corresponding to a sub-band of a system bandwidth of the co~nmunicationn ode; a
communications control module for controlling comrnunicatio~lsw ith the com~nullicationn ode
and operable: i) to receive control data from the communication node in one of a plurality of
predefined control data formats, the control data formats including a plurality of legacy control
data formats each comprisiilg a different number of bits and one or more new control data
formats that each have the same number of bits as a legacy control data format, the received
control data comprising resource allocation data that allocates, within a sub-frame, resource
5 blocks for communicating with the communication node; ii) in the case that the received control
data is in a control data format that has the same number of bits as another control data format, to
receive additional control data that indicates which control data format has been used; and a
control data interpreter module that interprets the received control data format in accordailce
with the legacy control data format or in accordance with the new control data forinat in
10 dependence upon the received additional control data.
The communication control module may be arranged to receive the additional control
data within the control data format.
Alternatively, the communication control module may be arranged to receive the
additional control data within another different control data format.
15 The invention also provides, for all methods disclosed, corresponding computer programs or
computer program products for execution on corresponding user communications devices or
network communications devices. The invention also provides user commullications devices
and network communications devices configured or operable to implement the methods and
components thereof and methods of updating these.
2 0
Brief Description of Drawings:
These and various other aspects of the invention will become apparent, froin the
following detailed description of embodiments which are given by way of example only and
which are described with reference to the accompanying drawings in which:
25 Figure 1 schematically illustrates a communication system comprising a number of user
mobile (cellular) telephones which communicate with a base station connected to the telephone
network;
Figure 2a schematically illustrates a generic frame structure used in coinn~unicationso ver
the wireless links of the system shown in Figure 1 ;
3 0 Figure 2b schematically illustrates the way in which the frequency subcarriers are divided
into resource blocks and the way that a time slot is divided into a number
of OFDM symbols;
Figure 3 is a block diagram illustrating the main components of a base station shown in
Figure 1 ;
Figure 4 is a block diagram illustrating the main components of a mobile telephone
showil ill Figure 1 ;
Figure 5 illustrates the way in which a resource block is divided notionally into a control
channel (PDCCH) and a data channel (PDSCH);
5 Figure 6a schematically illustrates the way in which physical resource blocks are grouped
into resource block groups and how the resource block groups may be assigned using a Type 0
resource allocation technique;
Figure 6b schematically illustrates the way in which physical resource blocks are grouped
into resource block groups and how resources within the resource block groups may be assigned
10 using a Type 2 resource allocation technique;
Figures 6c and 6d schematically illustrate the way in which physical resource blocks are
grouped into resource block groups and how the resource block groups arranged into subsets and
illustrating the way in which resources within each subset may be assigned using a Type 1
resource allocation technique;
Figure 7 illustrates one way in which resources may be allocated that allows different
resource blocks within the same resource block group to be assigned for PDSCH and ePDCCH
when a Type 0 resource allocation technique is used;
Figure 8 illustrates another way in which resources may be allocated that allows different
resource blocks within the same resource block group to be assigned for DPSCH and ePDCCH
20 when a Type 2 resource allocation technique is used;
Figure 9 illustrates the way in which a legacy Type 1 allocation may be interpreted in a
new way to for the efficient allocation of resources combining control data and PDSCH;
Figure 10 illustrates another way in which a legacy Type 1 allocation may be interpreted
in a new way to for the efficient allocation of resources combining control data and PDSCH;
Figure 11 illustrates an example of enhanced PIlSC1-I resource allocation Type 0;
Figure 12 illustrates an example of enhanced PDSCH rcsource allocation Type 2;
Figures 13a and 13b illustrate Legacy PDSCH resource allocation Type 1 in 20MHz
bandwidth; and
Figure 14 illustrates an example of enhanced resource allocation Type 1 in 20MHz BW
30 with four partitions.
Detailed Description of Exemplary Embodiments:
Overview
Figure 1 schematically illustrates a mobile (cellular) telecommuliication system 1 in
which users of mobile telephones 3-0,3-1, and 3-2 can communicate with other users (not
shown) via a base station 5 and a telephone network 7. In this embodiment, the base station 5
uses an orthogonal frequency division multiple access (OFDMA) technique for transmitting the
downlink data to the mobile telephones 3; and the mobile telephones 3 use a single carrier
5 frequency division multiple access (FDMA) technique to transmit their uplink data to the base
station 5. In order that a mobile telephone 3 can transmit and receive data over the air interface,
the mobile telephone 3 needs to be allocated physical resource blocks (by the base station 5), and
the mobile telephone 3 must be notified of its resource assignments by means of control
signalling within, in the case of LTE, the Physical Downlink Control Channel (PDCCI-I).
10 LTE sub-frame data structure
Before discussing the specific ways in which the base station 5 allocates resources to the
mobile telephones 3, a description will be given of the general frame structure agreed for LTE
Release 8 (Re1 8) and beyond and therefore what these resources represent. As mentioned
above, an OFDMA technique is used for the downlink to allow the base station 5 to transmit user
15 data over the air interface to the respective mobile telephones 3; and an SC-FDMA technique is
used for the uplink to allow the mobile telephones 3 to transmit their data over the air interface to
the base station 5. Different sub-carriers are allocated by the base station 5 (for a predetermii~ed
amount of time) to each mobile telephone 3 depending on the amount of data to be sent in each
direction. These sub-carriers and temporal allocations are defined as physical resource blocks
20 (PRBs) in the LTE specifications. PRBs thus have a time and frequency dimension. The base
station 5 dynamically allocates PRBs for each device that it is serving and signals the allocations
for each sub-frame to each of the scheduled mobile telephones 3 over the PDCCH.
Figure 2a illustrates one generic frame structure agreed for LTE communications over the
air interface with the base station 5. As shown, one frame 13 is 10 msec long and comprises ten
25 sub-frames 15 of 1 msec duration (known as a Transmission Time Interval (TTI)). Each subframe
or TTI comprises two slots 17 of 0.5 msec duration. Each slot 17 comprises either six or
seven OFDM symbols 17, depending on whether the normal or extended cyclic prefix (CP) is
employed. The total number of available sub-carriers depends on the overall transnlission
bandwidth of the system. The 1,'I'E specifications define parameters for system bandwidths from
30 1.4 MHz to 20 MHz and one PRB is currently defined to comprise 12 consccutive subcassiers for
one slot 17 (although this could clearly be different). The transmitted downlillk signal comprises
NBW subcarriers for a duration oSNsymb OFDM symbols. It can bc represented by a resource
grid as illustrated in Figure 2b. Each box 20 in the grid represents a single sub-carrier for one
symbol period and is rcfersed to as a resource element. As shown, each PRB 2 1 is formed from
12 consecutive sub-carriers and (in this case) seven symbols for each subcarrier; although in
practice the same allocations are made in the second slot 17 of each sub-frame 15 as well.
Base Slation
Figure 3 is a block diagram illustrating the main coinponellts of the base station 5 used in
5 an embodiment of the invention. As shown, the base station 5 includes a transceiver circuit 3 1
which is operable to transmit signals to and to receive signals from the mobile telephones 3 via
one or more antennae 33 and which is operable to transmit signals to and to receive signals from
the telephone network 7 via a network interface 35. The operation of the transceiver circuit 3 1 is
controlled by one or more controllers 37 in accordance with software stored in memory 39. The
10 software includes, among other things, an operating system 4 1, a communications control
module 43, a resource allocation module 45 and a scheduler module 47.
The communications control module 43 is operable to control communications between
the base station 5 and the mobile telephones 3 and between the base station 5 and the network 7.
The resource allocation module 45 is operable for allocating the resources used by the
15 transceiver circuit 3 1 in its communications with the mobile telephones 3 for receiving uplink
data fi-om the mobile telephone 3 and for transmitting downlink data to the mobile telephone 3.
The scheduler module 47 schedules the mobile telephones 3 for data communication
opportunities within the sequence of sub-frames 15 forming the air interface between the base
station 5 and the mobile telephones 3. The resource allocation module 45 and the scheduler
20 module 47 work together to generate the resource allocation data and to send appropriate DCI
control data to the mobile telephones 3 to inform them of their allocations using the new
techniques described below.
Mobile Telephone
Figure 4 schematically illustrates the main components of each of the mobile telephones
25 3 show11 in Figure 1. As shown, the mobile telephones 3 include a transceiver circuit 71 which is
operable to transmit signals to and to receive signals from the base station 5 via one or more
antennae 73. As shown, the mobile telephone 3 also includes at least one controller 75 which
colitrols the operation of the mobile telephone 3 and which is connected to the transceiver circuit
71 and to a loudspeaker 77, a microphone 79, a display 81, and a keypad 83. The controller 75
30 operates in accordance with software instructions stored within memory 85. As shown, these
software instructions include, among other things, an operating system 87 and a co~nmunications
control module 89 having therein a control data interpreter module 91. The communications
control module 89 is operable to control communications with the base station 5 using the
resources allocated by the base station 5. The control data interpreter module 91 is configured to
interpret the control information (in the manner discussed in more detail below) received from
the base station 5 to determine the resources allocated by the base station 5 for use by the mobile
telephone 3 in its communications with the base station 5.
In the above description, the base station 5 and the mobile telephone 3 are described, for
5 ease of understanding, as having a number of discrete modules (such as the communications
control, resource allocation and scheduler modules). Whilst these modules may be provided in
this way for certain applications, for example where an existing system has been modified to
implement the invention, in other applications, for example in systems designed with the
inventive features in mind from the outset, these modules may be built into the overall operating
10 system or code and so these modules may not be discernible as discrete entities. Where separate
modules are provided, the functionality of one or more of the above modules may be performed
by a single module. For example, the functionality of the resource allocation module and of the
scheduler module may be performed by a single scheduler module.
Resource Alloccrtion
15 The resource blocks 21 are allocated to the mobile telephones 3 by the resource
allocation module 45 in integer multiples of one resource block in the frequency domain. The
minimum unit of resource that is assigned to a mobile telephone is one resource block 21. These
resource blocks do not have to be adjacent to each other. The base station 5 decides on which
mobile telephones 3 are to be allocated resources. This scheduling decision is taken by the
20 scheduler module 47 and can be modified every transmission time i~lterval( TTI) of 1 ms. The
scheduling algorithm used by the base station 5 takes into account the radio link quality situation
of different mobile telephones 3, the overall interference situation, Quality of Service
requirements, service priorities, etc. in accordailce with existing techniques.
Figure 5 illustrates one resource block 2 1 across two slots (one sub-frame 15); and shows
25 how the resources within the block are typically split between the Physical Downlink Control
Chaiinel (PDCCH) 23; and the Physical Downlink Shared Channel (PDSCH) 25. The PDCCH
23 serves a variety of purposes. Primarily, it is used to convey the scheduling decisions to
individual mobile telephones 3, i.e. scheduling assignments for uplink and downlink
transmissions. The PDCCH 23 is located in the first OFDM symbols of a sub-frame 15. An
30 additional Physical Control Forinat Indicator Cllannel (PCFICH) carried on specific resource
elements in the first OFDM sy~nbool f the sub-frame 15 is used to indicatc the number of OFDM
symbols for the PDCCH (1, 2, 3, or 4 symbols are possible). The PCFICH is needed because the
load on the PDCCH can vary, depending on the number of mobile telephones 3 in a cell and the
signaling fonnats conveyed on the PDCCH 23. The information cai~iedo n the PDCCI-I is
referred to as downlink control information (DCI). Depending on the purpose of the control
message, different formats of DCI are defined. The reader is referred to TR 36.2 13 (V 10.6.0),
tlie content of which is incorporated herein by reference, for further details of the DCI formats.
Figure 5 illustrates the situation wliere the PDCCH 23 is transmitted using the first three
5 OFDM symbols of the sub-frame 15. The remaining resources are provided for the PDSCH 25.
Sometimes, however, the first OFDM symbols do not have enough capacity to carry all the
desired control data for the mobile telephones 3 being served by the base station 5 and a recent
proposal is to transmit some control data for individual mobile telephones 3 within the OFDM
symbols usually used for the PDSCH 25. One example of such control data is transmitted within
10 a control channel that is referred to as the enhanced PDCCH (ePDCCH). In addition to
increased control channel capacity, the use of such ePDCCH channels allows for mobile
telephone specific beam-forming and frequency selective scheduling to be applied to the
ePDCCH transinissions and to make it easier to co-ordinate ePDCCH between neighbouring
base station cells to reduce interference. However, the transmission of the ePDCCH in the
15 OFDM sylnbols usually used to carry the PDSCH 25 causes problems for the efficient allocation
of resources in the PDSCH 25 by the base station 5. To understand these problems, a description
will now be give11 of different types of resource allocation techniques that have been agreed for
use in the LTE communication system, these include Type 0 allocations, Type 1 allocations and
Type 2 allocations.
20 Type 0 Allocation
Figure 6a illustrates how the physical resource blocks 2 1 are grouped into a plurality of
consecutive resource block groups (RBGs) 27. Where possible each group contains an equal
number of resource blocks known as the RBG size (P), although where the number of
consecutive resource blocks is not exactly divisible by the desired RBG size, the last group may
25 contain fewer resource blocks. Figure 6a illustrates the case where the RBG size is four and
shows the first five RBGs - RBGO to RBG4.
In resource allocations of Type 0, the resource block assignment information (generated
by the base station and sent to a mobile telephone 3) includes a bitmap indicating the resource
block groups (RBGs) that are allocated to that scheduled mobile telephone 3. The order of tlie
30 KBG to bitmap bit mapping is in such a way that RBG 0 to RBG N R ~ " are mapped to MSB to
LSB of the bitmap (although it could of course be the other way around). The RBG is allocated
to the mobile telephone 3 if the corresponding bit value in the bitinap is 1, the RBG is not
allocated to the mobile telephone 3 otherwise, as described in section 7.1.6.1 of 3GPP, TR36.2 13
(V10.6.0). Figure 6a, illustrates an example of part of the bitmap 29 that is assigned to a
scheduled mobile telephone 3, illustratillg in this case that the scheduled mobile telephone 3 has
been allocated the resource blocks in groups RBGO, RBGI, RBG3 and RBG4.
As those skilled in the art will appreciate, when control data is also transmitted in the
5 region normally assigned for the PDSCH 25, some of the resources within a RBG 27 may not be
available for carrying user data even though they do not contain control data. For example, if
RBG15 is used to carry an ePDCCH for the scheduled mobile telephone 3 (or the ePDCCH for
another mobile telephone), then the other resources in the same resource block group can't be
allocated for the PDSCI-I as the legacy Type 0 resource allocation data can only allocate
10 resources in units of resource block groups. This leads to a fragmented and wasteful use of the
available resources.
Type 2 Allocation
In resource allocations of Type 2, the resource block assignment information indicates to
a scheduled mobile telephone 3 a set of contiguously allocated virtual resource blocks, as
15 described in section 7.1.6.3 of 3GPP, TR36.213 (V10.6.0). For DCI format 1 A, a Type 2
resource allocation field includes a resource indication value (RIV) corresponding to a starting
resource block ( RB.5tar/ ) and a length in terms of virtually contiguously allocated resource
blocks L('l~l~. 5F igure 66 illustrates an example resource allocation 30 that identifies RBI as the
starting resource block and including a length value correspollding to 14 resource blocks -
20 meaning that RBI to RB 14 are allocated to that scheduled mobile telephone 3 in that sub-frame
15. However, there is an issue for Type 2 resource allocation (which also applies to Type 0
resource allocation as well) when the mobile telephone 3 is allocated for contiguous resource
blocks and ePDCCHs for both DL (downlink) and UL (uplink) grants for the same mobile
telephone 3 are located within those contiguous resource blocks. In particular, if the mobile
25 telephoi~e3 can not detect the UL grant, it will result in the mobile telephone 3 not being able to
decode the PDSCI-I as well as corrupting the DL HARQ buffer (used for acknowledging receipt
of downlink data). Further, since the 1-IARQ buffer is corrupted, such transmissioi~e rrors can't
be recovered by HARQ retransmissions and so retransmission must be performed by higher
layers (i.e. the RLC layer). The simple solution to this problem is to limit the range of the
30 resources allocated to a scheduled mobile telephone 3 so that the allocated PDSCH resources do
not overlap with the control data, but again this leads to inefficient use (i.e. gaps) of the available
resources in the PDSCI-I 25.
Type I Allocation
In resource allocations of Type 1, the resource block groups are divided into subsets. An
example of this is illustrated in Figures 6c and 6d. In particular, these Figures illustrate the
resource blocks for a 20MHz supported bandwidth which is divided into one hundred resource
blocks. These resource blocks are grouped into twenty five resource block groups each of which
(RBGO to RBG24) contains four resource blocks (RBG size = 4). The physical resource blocks
5 are indexed consecutively across the bandwidth (typically from zero to ninety-nine for 20MHz).
The resource block groups are further arranged in to a plurality of subsets each of which
includes a plurality of resource block groups distributed evenly across the bandwidth. The
number of RBG subsets for a pai-ticular bandwidth and the spacing between resource block
groups within tlie subset are both equal to the RBG size. By way of illustration, in the example
10 of Figure 6c and 6d, the twenty five resource block groups are arranged into four (i.e. the RBG
size for 20MHz) subsets. The first subset contains the first, fifth, ninth, thirteenth, seventeenth,
twenty first and twenty fifth resource block groups; the second subset contains the second, sixth,
tenth, fourteenth, eighteenth and twenty second resource block groups; the third subset contains
the third, seventh, eleventh, fifteenth, nineteenth and the twenty third resource block groups; and
15 the foui-th subset contains the remaining resource block groups.
A similar approach is used for dividing up different supported bandwidths. The RBG
size (and hence number of subsets) for the different bandwidths is illustrated in the table below:
System
bandwidth,
IJL
2 0 Where 'P' is the RBG size (and hence the nuinber of RBG subsets) and N~~ is the
number of resource blocks into which the bandwidth is divided for downlink transmission.
As described in TS 36.21 3, the legacy Type 1 resource allocation technique applies one
bit for one resource block for the resource blocks in a selected subset of the RBGs. Type 1 can
not allocate contiguous resource bloclts of more than one RBG (i.e. it can only handle distributed
25 resource blocks to achieve frequency diversity gain), hence, its applicatioil for frequency
selective scheduling is limited. I11 detail, as illustrated in Figure 6c and 6d rcspcctively, Type 1
resource allocatioii has the following fields:
The first field, with ceil(log2P) bits, is used to indicate the selected RBG subset from
among the RBG subsets.
The second field, with one bit, is used to indicate a shift of the resource allocatioi~
span within a subset. A bit value of 1 indicates shift is triggered to the right (Right
justified - illustrated in Figure 4d). Otherwise the shift is triggered to the left (Left
justified - illustrated in Figure 4c).
The third field includes a bitmap, where each bit of the bitmap addresses a single
resource block in the selected RE3G subset. The size of this field is
Therefore, a scheduled mobile telephone 3 will use the first field in the received resource
10 allocation data to identify the subset of mGs, the second field to identify if the allocation is left
or right shifted and the third field to identify the resource blocks in the subset that have been
allocated.
New Resource Allocatiorz Tecltniques
A description will now be given of a number of new resource allocation techniques that
15 help to at least alleviate some of the inefficiencies discussed above.
Solution I
As a first solution to at least some of the above problems, the base station 5 is also
assanged to generate and send supplementary information (e.g. an ePDCCH allocation
indication) to the mobile telephone 3 to indicate which resource blocks should be excluded froin
20 the legacy resource allocation (Release 10 Type 0, Type 1 and Type 2 resource allocation
techniques - as described above) because they contain ePDCCH transmissions. The mobile
telephone 3 (and in particular the control data interpreter module 91) is arranged to combine the
supplementary information with its legacy resource allocation message in order to work out the
actual downlink resources allocatcd to it by the base station 5. In this way, resource blocks
25 which themselves do not contain an ePDCCH transmission but which form part of a resource
block group that does contain at least one ePDCCH transmission, can still be allocated to the
mobile telephone 3 for the PDSCII.
Only mobile telephones 3 colnpatible with later versions of the LTE standard (Rel-1 1 and
beyond) would be able to read and use the supplementary information. Older mobile telephoncs
30 3 would not, but the base station 5 can ensure that resource allocations for such "legacy" mobile
telephones 3 do not also include resources used for ePDCCH (or other similar control data that is
transmitted in thc OFDM symbols used for the PDSCII 25), thereby ensuring that the system
retnains backwards compatible.
ConJguration of the ePDCCH Allocation Region
To reduce the size of the supplementary information, a subset of physical resource blocks
(the 'ePDCCH region') may be predefined (known to both the base station 5 and the mobile
telephones 3 in advance), that impose a restriction that the ePDCClI transmissions can only be
5 located in this sub-set of resource blocks. In this case, the supplementary information only has
to describe which resource blocks in this subset should be excluded from the legacy resource
allocation. This can significantly reduce the signalling overhead for the supplementary
information.
The 'ePDCCH region' subset of resource blocks could be signalled in advance to the
10 mobile telephone 3 by higher layer signalling (e.g. Radio Resource Control (RRC) signalling) or
on a broadcast channel. Alternatively this sub-set of resource blocks could change dynamically
from sub-frame 15 to sub-frame 15 based on a pre-defined pattern which is again signalled to the
mobile telephone 3 by higher layer signalling or on a broadcast channel, or based on a fixed rule.
For example, the exact location of the set of ePDCCH resource blocks for a given sub-frame 15
15 could be implicitly determined using some defined calculation involving, for example, the Cell
ID of the base station cell and the sub-frame number for that sub-frame 15. In one embodiment,
the resource blocks in the ePDCCH region are conceiltrated into one part of the system
bandwidth, although there may be advantages to distributing the resource blocks of the ePDCCH
region across the system bandwidth - to allow the ePDCCH for each mobile telephone 3 to be
20 transmitted in a region of the system bandwidth that has good channel conditions between the
base station 5 and the mobile telephone 3 (thereby increasing the chances of successfully
communicating the ePDCCH to the mobile telephone 3).
Signalling of the ePDCCHAllocation Indication
One possible form that the supplementary information can take is a bitmap, wit11 one bit
25 for each physical resource block in the ePDCCH region subset, indicating whether or not the
corresponding resource block is to be excluded from the legacy resource allocation.
Alternatively, multiple resource block subsets, of varying sizes, could be defined in
advance and each subset associated with an index value. The base station 5 and the mobile
telephones 3 would maintain data (e.g. a look up table) that identifies the resource block subsets
30 and their associated index value. In operation, in each sub-fiaine 15 the base station 5 would
select the resource block subset which it judges to be most advantageous to contain the required
ePDCCM transmissions in that sub-frame 15, and it would signal the associated index value to
the inobile telephones 3. In response, the inobile telephones 3 would receive the signalled index
value and would use the stored data to identify the associated resource block subset. The mobile
telephones 3 would then exclude all the resource blocks in the indicated resource block subset
from its legacy resource allocation (regardless of whether or not they actually contain ePDCCH
transmissions). Whilst this approach may be less efficient in terms of resource block usage than
the bitmap method (because resource blocks in the selected resource block subset which do not
5 actually contain ePDCCH transmissions would be wasted), the size of the supplementary
information can be smaller than the bitmap method in some cases which reduces signalling
overhead.
There are different options how to signal the supplementary information to the mobile
telephones 3 as follows:
10 ePDCCH DCI formats: For both Type 0 and 2, the supplementary information
can be placed in the DCI format as a part of the resource allocation scheme when
ePDCCH is configured. The number of bits required for this supplementary
information should be less than or equal to the size of the ePDCCH region in
ter~nso f number of resource blocks contained therein. For example the number
of bits for the supplementary information for a 1 OMHz system bandwidth can be
one of {8bits, 12bits, 16bits).
ePCFICH or new DCI format: the supplementary information can also be
signalled dynamically (in each sub-frame 15) in the ePCFICH if it is agreed or in
a new DCI format that is supposed to indicate the ePDCCH regionhesources.
Thus the supplementary information will indicate dynamically the actual resource
blocks occupied by the ePDCCHs for all mobile telephones 3 from the set of
resource blocks allocated to the ePDCCI-I region. In this case, the size of the
supplementary inforinatin will be equal to the size of the ePDCCH region in terms
of number resource blocks contained therein.
2 5 The supplementary i~lformationm ay be signalled to each mobile telephone 3 individually
as an extension of its legacy resource allocation, or it may be separately broadcast to all mobile
telephones 3 in the base station cell.
If the supplementary information is signalled to each mobile telephone 3 individually as
an extension of its legacy resource allocation, it would allow for the possibility of signalling
30 different supplementary inforn~ationto each mobile telephone 3. In some scenarios this could
provide additional flexibility by allowing, for example, two mobile telephones 3 to be assigned
partially ovcrlapping legacy rcsource allocations, with the mobile telephone-specific
supplementary information being used to resolve the conflict (so that the same resources are not
allocated to both mobile telephones 3).
Additionally, if the suppleme~ltaryin formation is signalled to each mobile telephone 3
individually as an extension of its legacy resource allocation then the supplementary information
and legacy resource allocation may be combined into a single ePDCCH transmission.
Further, if the supplementary information is signalled to each mobile telephone 3
5 individually as an extension of its legacy resource allocation (within the mobile telephone's own
DL Grant ePDDCH) then the supplementary information need not include an indication of the
mobile telephone's own DL Grant ePDCCH allocation, since it may be assumed that the mobile
telephone 3 already knows this by virtue of the fact that it has decoded the DL Grant ePDCCH
message.
10 Further still, if the supplementary information is signalled to each mobile telephone 3
individually as an extension of its legacy resource allocation, the supplementary information
only needs to describe that part of the ePDCCH region resource block subset which overlaps
with the mobile telephone's legacy resource allocation (is. those resource blocks which are
included in both the ePDCCH region PRB subset and the mobile telephone's legacy resource
15 allocation). Since the mobile telephone 3 knows both the ePDCCH region PRB sub-set and its
own legacy resource allocation, it can compute the overlapping part and interpret the
supplementary information accordingly. This will typically reduce the size of the
supplementary information. However this would also mean that the size of the supplementary
information is unknown to the mobile telephone 3 in advance, requiring additional blind
20 decoding attempts.
In particular, as discussed above, control data sent to a mobile telephone 3 can have one
of a number of predetermined formats (DCI formats, each having a different size) and the mobile
telephone 3 has to try to decode the PDCCH 23 to find out if it contains control data in one of
those formats for that mobile telephone 3. As the mobile telephone 3 typically does not know
25 which DCI format may be used, each decoding attempt is referred to as a "blind" decoding
attempt. Control data for a specific mobile telephone 3 is scrambled with the mobile telephone's
identity, so that only that specific mobile telephone 3 call decode the control data. Therefore, if
the supplementary information can have variable size, then this will require each mobile
telephone 3 to perform different blind decoding attempts for each of the possible sizes. To
30 address this issue, it may be advantageous to restrict the number of supplementary i~lformatio~l
bits to be one of a predefined set of lengths, e.g. (2, 4, 8, 12, 16) bits, each correspo~~dintog a
different ePDCCH DCI format size. Alternatively, the DCI format size selected in a given subfi-
ame 15 could be separately signalled on PDCCM (if it is present) or on ePCFICH or on a
separate ePDCCH tra~~s~nisscioonnt aining only the DCI format size indication.
Examples of Solution I
In this section we give examples of the case in which the supplementary infornlation is
signalled to each mobile telephone 3 individually as an extension of its legacy resource
allocation.
5 As discussed above, in resource allocations of Type 0, the resource block assignment
information includes a bitmap indicating the resource block groups (RBGs) that are allocated to
the scheduled mobile telephone 3. Figure 7 shows an example of a PDSCH allocation which
overlaps with ePDCCHs allocations for the same mobile telephone and the ePDCCHs allocations
for other mobile telephones 3. In the figure, 'Part- 1 ' corresponds to the legacy resource
10 allocation 29 (ie. a Rel-10 Type 0 allocation) and 'Part-2' corresponds to the supplementary
information 95, which takes the form of a bitmap. As can be seen from Figure 7, the legacy
resource allocation 29 assigns resource block groups RBGO, RBG1, RBG3 and RBG4 to the
mobile telephone 3. Figure 7 represents the ePDCCH region with the bold boxes that correspond
in size to whole resource block groups, but in general this need not be the case. The ePDCCH
15 regions cossesponding to resource block groups RBG4 and RBGO both include PDSCH
allocations for the mobile telephone 3 as well as ePDCCH allocations for the mobile telephone 3
and ePDCCH allocations for other mobile telephones. As shown in Figure 7, the supplemental
information 95 is split, in this example, into a respective bitmap portion (95a and 95b) for each
ePDCCH region that includes both a PDSCH allocation and an ePDCCI1 allocation. In practice,
20 a single bitmap 95 would be signalled to the mobile telephone 3 and then the mobile telephone 3
would relate the relevant parts of the bitmap to the corresponding parts of the PDSCH resource
allocation 29.
As can be seen from bitmap portion 95a, the bits thereof corresponding to the resource
blocks containing the ePDCCH portions of resource block group RBG4, are set at the value "0"
25 and the other bits are set at the value "1". This is similarly true for the bits of the second bitmap
portion 95b in respect of resource block group RBGO. Accordingly, the mobile telephone 3 can
receive the legacy resource allocation 29 and then use the bitlnap 95 to exclude from the
allocated resources those that correspond to ePDCCI-I transmissions.
With regard to Type 2 rcsource allocations, as discussed above, the legacy resource block
30 assignment information 30 indicates to a scheduled mobile telephone 3 a set of contiguously
allocated virtual resource blocks. An example of this method is illustrated in Figure 8. As
before, 'Part-2' corresponds to the new supplementary information 97. I11 this example, the Part-
2 information 97 is also in the form of a bitmap (notionally split into portions 97a and 97b),
where each bit of the bitinap addrcsscs a single virtual resource block in the set of virtual
resource blocks that overlap between the ePDCCH region (also outlined by bold boxes) and the
mobile telephone's legacy Type-2 resource allocation 30, in such a way that the MSB to LSB of
the bitmap are mapped to the virtual resource blocks in increasing frequency order. A virtual
resource block is not allocated to the mobile telephone 3 for the PDSCH 23 if the corresponding
5 bit value in the bitmap 97 field is 0, and the virtual resource block is allocated to the mobile
telephone for the PDSCH 23 if the corresponding bit value in the bit field is 1. In this example,
as the mobile telephone 3 has not been allocated resources in resource block group RBG4, there
is no need for the supplemental information 97 to include bits in respect of those parts of RBG4
corresponding to ePDCCH allocations.
10 Solution 2
Instead of sending supplementary information, some or all of the existing Rel-10 DCI
formats may be "overloaded" (in the sense of the use of the term in computer science), by
defining one or more new DCI formats using the same number of message bits as the legacy DCI
format, and then informing the mobile telephone 3 which overloaded format it should use to
15 interpret the message. More specifically, at present, when the mobile telepllone 3 decodes a DCI
format, it knows which DCI format has been decoded by its length - so it inherently knows how
to interpret the bits in that message. However, by adding new DCI formats having the same size
(in terms of number of bits), the mobile telephone 3 now does not know how to interpret the bits
- as they will need to be interpreted differently between the legacy DCI format and the new DCI
20 format. Therefore, the mobile telephone 3 needs to be told how to interpret the message as well.
The purpose of "overloading" the DCI formats in this way is to extend the repertoire of resource
allocation types that the base station 5 can use whilst avoiding increasing the number of different
DCI format sizes (which would require additional blind decoding attempts by the mobile
telephone 3). The "cost" of doing so is that the mobile telephone 3 now also has to be told if the
25 received DCI format is a legacy DCI format or a new DCI format.
The way in which the base station informs the mobile telephone 3 as to whether the DCI
format is new or legacy (and if there are multiple new formats - which one should be used) may
be specific to the mobile telephone 3 or it may be generic to all new Rel-1 1 devices. Of course,
legacy mobile telephones 3 will only support legacy DCI formats (and so the base station 5 can
30 only use the legacy DCI fonnats when allocating resources to those legacy mobile telephones).
The data informing the mobile telephonc 3 if the DCI format is legacy or new may be signalled
to the mobile telephone 3 using higller layer signalling or it could be signalled dynamically by
adding a 'format indicator' field to the legacy DCI format. On detecting a legacy DCI format the
UE would first read the forlnat indicator and then interpret the remainder of the message
accordingly.
Examples of Proposed Solution 2
In this section we give examples of the case in which overloading is used to define new
DCI formats.
5 As discussed above, in resource allocations of Type 0, the resource block assignment
information illcludes a bitmap indicating the resource block groups (RBGs) that are allocated to
the scheduled mobile telephone 3. Resource allocation Type 0 can be overloaded in such a way
that the existing resource allocation bit-map for one or more resource block groups can be
interpreted differently based on the detected ePDCCH grants in these resource block groups.
10 For example, if the mobile telephone 3 detects a DL grant ePDCCH transmission in a particular
resource block group, then the mobile telephone 3 may be programmed to infer that that resource
block group is part of the mobile telephone's PDSCH allocation (note that the base station
scheduler 47 will have to allocate those resources to the mobile telephone 3 accordingly). In this
case, the bit in the RBG bitmap 95 cossesponding to this resource block group may be re-used
15 for another purpose. For example, it may be used to signal the presence or absence of an UL
grant ePDCCH transmission for the same mobile telephone 3 in the same resource block group.
This could be useful in case the mobile telephone 3 fails to detect the UL grant ePDCCH
transmissioil by itself, which would otherwise result in a PDSCH decoding error. Preferably, the
UL grant and the DL grant are allocated in adjacent resources so that if this bit indicates the
20 presence of an UL grant, the mobile telephone 3 can decode the PDSCH by excluding the
resources adjacent the DI, grant. Additionally, if this bit indicates that there is no UL grant, then
the mobile telephone 3 does not need to perform any blind decoding to try to find an UL grant
DCI message, hence less energy is consumed by the mobile telephone 3.
Enhanced Type 1 Resource Allocation
2 5 One way of overcomiilg the problem of resource fragmentation as a result of allocating
the PDSCH around the ePDCCI-I channel for any mobile telephones 3, is to have a finer RB
granularity of resource allocation mechanism (i.e. one RB resolution) that can handle both
contiguous and non-contiguous resource allocations, and applicable to frequency selective
? - scheduling. 1 here are few options:
3 0 Option 1: Overloading the Type I resource allocation into contiguous RB-level
resolution via Radio Resource Control (RRC) reconfiguration as follows:
Default: same as current legacy Type 1 approach (distributed subset approach
discussed above) intended to achieve frequency diversity gain, for example, for
nlobile telepho~lesa t the edge of the base station's cell.
RRC signalling in semi-static manner to change the default to contiguous resources
with one resource block granularity as illustrated in Figure 9. The purpose is to
achieve frequency selective scheduling (such that different mobile telephones 3 are
scheduled onto different frequelicy sub-bands - depending on the radio conditions
between the base station 5 and the mobile telephone 3 at the time) and also to tackle
the issue of resource fragmentation. In this case, the mobile telephone 3 would
interpret the received DCI message in a different way (and of course the base station
5 would change the way in which it generates the DCI message) as follows:
The first field with ceil(logzK) bits is used to indicate a selection of one out of K
partitions of the system bandwidth where each bandwidth part contains
contiguous resource blocks with one RB resolution. The example illustrated in
Figure 9, shows the specific case where the number of partitioils equals the
number of resource blocks in each resource block group (P).
The second field with one bit is used to indicate a shift of the resource allocation
span within the selected bandwidth part. A bit value of 1 indicates shift is
triggered to the right (Right justified), otherwise shift is triggered to the left (Left
justified).
The third field includes a bitmap, where each bit of the bitmap addresses a single
RB in the selected bandwidth part and indicates if the resource block is allocated
to the mobile telephone 3. The size of this field is
N;?' = [N:; I P ] - r l o g , ( ~ ) l - 1 .
Option 2: Overloading the Type 1 resource allocation into contiguous RB-level
resolution via dynamic signalling. Option 1 above just divided the system bandwidth into a
small number of K partitions of contiguous resources with one RB granularity; and the staring
25 position of each partition is fixed. In order to provide Inore flexibility in the starting position, as
shown in Figure 10, the resource allocation Type 1 can be further enhanced by having only two
fields which can be signalled dynamically as follows:
The first field with I l o g , (N,",)) I bits is used to indicate the start RB of the resource
allocation anywhere in the system bandwidth.
The second field includes a bitmap, where each bit of the bitmap addresses a
single RB in the resource allocation span and indicates if the resource block is
allocated to the mobile telephone 3. 'I'he size of this field
is^;;^^^ = [N;; I P -~[ I O ~ ~ ( N ; , : ) ~ .
As a further solution, it may be possible to define new DCI formats. For example, if a
new DCI format is provided for Type 1 allocations, then the size of the Type 1 resource
allocation can be changed which allows further options as follows:
Option 3: This option is similar to Option 1 above, but one additional field is introduced
to indicate dynamically (instead of by RRC signalling) either legacy Type 1 or new Type 1 as
5 follows:
The first field with I-bit is introduced to indicate either legacy Type 1 or new
Type 1.
The second field with ceil(logzK) bits is used to indicate selection of one out of K
partitions of the system bandwidth where each bandwidth part contains
contiguous RBs with one RB resolution.
The third field includes a bitmap, where each bit of the bitmap addresses a single
RB in the selected bandwidth part and indicates if the resource block is allocated
to the mobile telephone 3. The size of this field is
N ; T 1 = [N;; 1 P] - r l o g l ( ~ )-l I .
15 Option 4: This option is similar to Option 2 above, but instead of reducing the resource
allocation span (depending on the number of bits used to identify the start RB), the starting
position is signalled dynamically as follows:
The first field with I log, (N;;) I bits is used to indicate the start RB of the resource
allocation anywhere in the system bandwidth.
The second field includes a bitmap, where each bit of the bitmap addresses a
single RB in the resource allocation span and indicates if the resource block is
allocated to the mobile telephone 3. The size of this field is ,y;iPm = 1 I;; / p 1.
The provision of new DCI formats would also allow the supplementary information
described above in solution 1 to be included with the allocation information provided by the
25 legacy DCI format. The disadvantage of defining new DCI formats is that it increases the
number of blind decoding attempts that each mobile telephone 3 has to perform to find any
control data that may be allocated it.
Modifications citzcl A ltert~atives
A number of cmbodiments have been described above. As those skilled in the art will
30 appreciate, a number of modifications and alterilatives can be made to the above embodiments
whilst still benefiting fro111 the inventions embodied therein. By way of illustration only a
number of these alternatives and modifications will now be described.
In the above embodiments, a mobile telephone based telecommunication system was
described in which the above described resource allocation techniques were employed. As those
skilled in the art will appreciate, the techniques for scheduling resources for such
communications can be employed in any communication system that uses a plurality of resource
blocks. In the general case, the base station would be replaced by a colnlnunication node which
communicates with a number of different user devices. For example, while the term 'mobile
5 telephone' has been used throughout the description the methods and apparatus described are
equally applicable to any communication user device, for example, a personal digital assistant, a
laptop computer, a web browser, etc.
In the above embodiments, the base station was assumed to have an operating bandwidth
of 20MHz and each resource block included 12 or 24 sub-carriers. As those skilled in the art
10 will appreciate, the invention is not limited to this particular size of bandwidth or resource block
size or to the frequency spacing of the sub-carriers described.
In some of the above embodiments, the mobile telephones 3 are informed by higher layer
signalling or over a broadcast channel of one or more predefined resource block sub-sets that are
referenced by the supplementary information to identify the resources containing the ePDCCH.
15 As those skilled in the art will appreciate, as an alternative, this predefined information may be
permanently stored within the mobile telephones from the time of their initialisation. However,
this is not preferred as ideally the predefined resource block subsets will be different for each
base station 5, depending on the prevailing local transmission characteristics within the system
bandwidth.
2 0 In the above embodiments, a number of software modules were described. As those
skilled will appreciate, the software modules may be provided in compiled or un-compiled form
and may be supplied to the base station or to the mobile telephone as a signal over a cornputer
network, or on a recording medium such as a CD-ROM or the like. Further, the functionality
performed by part or all of this software may be performed using one or more dedicated
25 hardware circuits. However, the use of software modules is preferred as it facilitates the
updating of the base station 5 and the mobile telephones 3 in order to update their functionalities.
Further, the modules described above may not be defined as separate modules and may instead
be built in to the operating system of the base station andlor the mobile telephone.
Various other modifications will be apparent to those skilled in the art and will not be
30 described in further detail here.
The following is a detailed description of the way in which the present inventions may be
implemented in the currently proposed 3GPP standard. Whilst various features are described as
being essential or necessary, this may only be the case for the proposed 3GPP standard, for
example due to other require~nentsim posed by the standard. These statements should not,
therefore, be construed as limiting the present invention in any way.
1 Introduction
In principle, for frequency selective scheduling, UE will be allocated to some of its best
resource blocks (RBs) for both PDSCH and ePDCCH based on CSI reported by the UE. This
5 means that the ePDCCH region will be allocated in UE-specific manner at least for localized
allocations, resulting in ePDCCH regions for different UEs being reserved in different locations
of the system bandwidth. In addition, it has been agreed in RAN1#68 that multiplexing of
PDSCH and ePDCCH within a PRB pair is not permitted. So, in order to utilize the resources
efficiently, any unused PRBs in the ePDCCH region should be reused for PDSCH transmission.
10 However, there are issues with the current resource allocation schemes. Firstly, when
PDSCH resource allocation Type 0 is applied to the UE and ePDCCH occupies a number of RBs
less than the RBG size of the system bandwidth, the remaining RBs not assigned for ePDCCH
within that RBG can not be used for PDSCH of the same UE creating holes or fragmented
resources in the system.
15 Secondly, regarding PDSCH resource allocation Type 2, when UE is allocated to
contiguous RBs and ePDCCHs for both DI, and UL grants of the same UE are located within
those contiguous RBs (i.e. PDSCH overlaps with actual ePDCCH resources) and if UE fails to
detect the UL grant, it will result in UE unable to decode PDSCH as well as corrupting the DL
HARQ buffer.
2 0 Thirdly, if resource allocation Type 1 is employed to fill the holes created by ePDCCHs
of different UEs, it can not handle the fragmented resources because it can only assign PDSCH
to a subset of distributed RBGs which adds unnecessary scheduling restrictions to the system,
especially for frequency selective scheduling.
These issues have been discussed also in some other contributions in RAN1#69 [2-41.
25 Further more, we think that the issues discussed above of resource fragmentation and
how to reuse the unused PRB pairs in the ePDCCH region are mainly associated with the
following cases for ePDCCH PRB-pairs indications:
Dynamic ePDCCH PRB-pairs indication with implicit signaling based on CSI reports: As
each UE's best sub-bands for ePDCCH allocation may locate in different sub-bands in the
30 system bandwidth, it will create fragmented resources and prevents large allocations for the
PDSCH transmission.
RRC signaling for ePDCCH PRB-pairs indication: If ePDCCM region is distributed in
the system bandwidth, it will also create fragmented resources in the system and prevents large
allocations for the PDSCI-I transmission.
In other cases where explicit and dynamic ePDCCH PRB indication solution is adopted
for Rel-1 1 such as signalling through PDCCM or ePCFICH, the above discussed issues do no
happen. Because in every subframe, eNB can schedule PDSCH on any PRB-pairs except for
the ones used for ePDCCH transmission using existing resources allocation types and as UE
5 knows the PRB-pairs that are currently used for ePDCCH transmission, it can skip them when
decoding PDSCH.
The details of the cases a), b), and other cases are described in our accompanying
contribution [5].
Therefore, in this contribution, we provide some solutions how to provide more
10 flexibility for the eNB scheduler in terms of resource allocation schemes so that fragmented
resources and any unused ePDCCH resources can be efficiently utilised for the same UE or
different UEs for the cases of dynamic ePDCCH PRB-pairs indication with implicit signaling
based on CSI reports and RRC signaling for ePDCCH PRB-pairs indication.
2 Enhanced PDSCH Resource allocation Type 0 and 2
15 Enhanced PDSCH Resource allocation of Type 0: In legacy PDSCH resource
allocation of Type 0, resource block assignment information includes a bitmap indicating the
resource block groups (RBGs) that are allocated to the scheduled UE. The RBG is allocated for
the UE if the corresponding bit value in the bitmap is 1; the RBG is not allocated to the UE
otherwise. However, when Type 0 is utilised for the UE where PDSCH overlaps with ePDCCH,
20 and ePDCCH occupies a number of RBs less than the RBG size of the system bandwidth, the
remaining RBs not assigned for ePDCCH within RBG can not be used for PDSCH for the same
UE resulting fragmented resources. Figure 11 shows an example of PDSCH allocation which
overlaps with ePDCCI-I region for the same and other UE. A possible solution to this issue is to
enhance PDSCH resource allocation Type 0 where eNB signals supplementary information to
25 the UE to indicate which VRBs should be excluded from the PDSCH resource allocation Type 0
because they contain ePLICC1-I transmissions. Then, UE combines the supplementary
information with its PDSCH resource allocation Type 0 in order to work out its actual resource
allocation. In this case, the PDSCH enhanced resource allocation Type 0 consists two parts.
Part-1 uses the legacy PDSCI-I resource allocation Type 0 to indicate dis-contiguous resource
30 allocation at RBG level. Part-2 contains the supplementary information which is a bit-map of a
single VRB in a selected RBG sets. The selected KBG sets of Part-2 are formed by the
overlapping RBGs indicated by Part 1 and the RBGs of the ePDCCH region. MSB to LSB of
the bitmap of part-2 are nlapped to the VRBs in increasing frequency order. The VRB is
allocated to the PDSCH for a given UE if the corresponding bit value in the bitmap field is 1;
otherwise the VRB is allocated to the ePDCCH for the same UE or different UE. The ePDCCH
region is the set of PRB pairs in which ePDCCH may be transmitted and can be configured
dynamically or semi-statically for the UE.
Enhanced PDSCH Resource allocation of Type 2: Legacy PDSCH resource allocation
5 Type 2 field consists of a resource indication value (RIV) corresponding to a starting resource
block ( K B ~ )~ afn~d ~a /le ngth in terms of contiguously allocated resource blocks L ( ' l ~ l ~.~ y However,
there is an issue for PDSCH resource allocation Type 2 when UE is allocated for contiguous
VRBs and ePDCCHs for both DL and UL grants for the same UE are assigned within those
contiguous VRBs and if UE can not detect the UL grant it will result UE not able to decode
10 PDSCH as well as corrupting the DL HARQ buffer. A similar solution to Type 0 can be
envisioned where eNB signals supplementary information to the UE to indicate which VRBs
should be excluded from the PDSCH resource allocation Type 2 because they contain ePDCCH
transmissions. Then, UE combines the supplementary information with its PDSCH resource
allocation Type 2 in order to work out its actual resource allocation. The enhanced PDSCH
15 resource allocation Type 2 has two parts. Part-1 uses the legacy resource allocation Type 2 and
Part-2 contains the supplementary information which is selected RBG sets where ePDCCH
region overlaps with PDSCI-I indicated by Part 1. An example of this method is shown in
Figure 12. Part-2 is a bit-map scheme of the selected RBG sets where each bit of the bitmap
indicates a single VRB in the selected RBG sets in such a way that MSB to LSB of the bitmap
20 are mapped to the VRBs in increasing frequency order. The VRB is allocated to the PDSCH for
a given IJE if the cosresponding bit value in the bitmap field is 1 ; otherwise the VRB is allocated
to the ePDCCH for the same UE or different UE. The ePDCCH region is the set of PRB pairs
in which ePDCCH may be transmitted and can be configured dynamically or semi-statically for
the UE.
25 Location of the supplementary information (i.e. Part-2) and number of bits: There
are different options how to signal Part-2 to the UE as follows:
Option-1: ePDCCH DCI formats: For both Type 0 and 2, Past-2 can be placed in
the DCI format as a part of the resource allocation scheme in a UE specific manner
when ef'DCCH is configured. The number of bits should be less than or equal to the
size of ePDCC1 I region in terms of number of VRBs. For example Part-2 bits for
10MHz bandwidth can be one of {2bits, 4bits, 8bits). If the number of
supplementary information bits is equal to the number or VRBs in the ePDCC1-I
region, any PDSCI-I resource allocation is possible without any scl~eduling
restrictions. However, if the number of supplementary information bits is less than
the number of VRBs in the ePDCCH region, the scheduler has to make some
restrictions on the PDSCI-I allocation so that the overlap between the PDSCI-I
resources and the ePDCCH region is limitted to the number of supplementary
information bits supported by the system bandwidth.
5 Option 2: ePCFICH or new DCI format: Part-2 can be signaled dynamically in the
ePCFICH if it is agreed or in a new DCI format and it is common to all UEs or group
of UEs. The supplementary information (Part-2) will indicate dynamically the actual
occupied VRBs by the ePDCCHs for all UEs from the set of VRBs pre-allocated for
the ePDCCH region. In this case, the size of Part-2 bits will be equal to the size of
10 ePDCCH region in terins of number VRBs, e.g. {8bits, 12bits, 16bits). The
ePDCCH region is reserved in advance to the UEs via RRC signalling (i.e. semistatic).
3 Enhanced Resource allocation Type 1
Legacy PDSCH Resource allocation Tvpe 1: The legacy PDSCH resource allocation
15 Type 1 applies one bit for one VRB in which the applicable VRBs are subsets of RBGs selected
from the system bandwidth in distributed manner (i.e. sub-sampling of the RBGs in the system
bandwidth) as shown in Figure 13a or 13b. PDSCH resource allocation Type 1 can not handle
contiguous VRBs of more than one RBG (i.e. it can only handle distributed VRBs to achieve
frequency diversity gain), hence, its application for frequency selective scheduling is very
20 limited. In detail as shown on Figures 13a and 13b respectively, PDSCH resource allocation
Type 1 has the following fields [I]:
The first field with ceil(ZogzP) bits is used to indicate the selected RBG subset
among RBG subsets.
The second field with one bit is used to indicate a shift of the resource allocation
span within a subset. A bit value of 1 indicates shift is triggered to the right (Right
justified). Otherwise shift is triggered to the left (Left justified).
The third field includes a bitmap, where each bit of the bitinap addresses a single
VRB in the selected RBG subset. The size of this field is
3 0 Enhanced PDSCH Resource allocation Type 1: One possible way of overcoming the
issue of resource fragmentation as a result of allocating PDSCH around the ePDCCH channel for
any UE is to have a finer VRB grailularity of resource allocation mechailism (i.e. one VRB
resolution) that can handle both contiguous and non-contiguous resource allocations, and
applicable to frequency selective scheduling. This can be implemented by modifying the
PDSCH resource allocation Type 1 to cover contiguous VRB-level resolution without changing
the size of the information bit from that of legacy PDSCH resource allocation Type 1 as follows:
Default: Distributed subset RBG (i.e. sub-sampling) same as current legacy PDSCH
resource allocation Type Type 1 intended to achieve frequency diversity gain, for
example, for high mobility UEs or cell edge UEs.
RRC signaling in semi-static manner to change the default allocation to cover
contiguous resources with one VRB resolution as shown on Figure 14. The purpose
is to achieve frequency selective scheduling and also tackle the issue of resource
fragmentation. The existing fields of legacy Type 1 could be reused differently as
follows:
The first field with ceil(Zog2P) bits is used to indicate a selection of one out of P
partitions of the system bandwidth where each bandwidth part contains
contiguous RBs with one RB resolution.
The second field with one bit is used to indicate a shift of the resource allocation
span within the selected bandwidth partition. A bit value of 1 indicates shift is
triggered to the right (Right justified), otherwise shift is triggered to the left (Left
justified).
The third field includes a bitmap, where each bit of the bitmap addresses a single
VRB in the selected bandwidth part. The size of this field is
N;;lJ1' = [N:; /PI - [ l o g , ( ~ ) l - 1 .
4 Conclusion
In this contribution, we have discussed solutions to provide more flexibility for the eNB
scheduler in terms of resource allocation schemes so that fragmented resources can be efficiently
utilized for the same UE or different UEs.
Proposal: Considcr enhanced PDSCH resource allocation schemes for Release-1 1 to
deal with the issue of fragmented resources if the following cases are agreed for ePDCCH PRBpairs
indication:
a) Dynamic ePDCCH PRB-pairs indication with implicit signaling based on CSI
reports
b) KRC signaling for ePDCCI-1 PRB-pairs indication
Various other modifications will be apparent to those skilled in the art and will not be
described in further detail here.
This application is based upon and claims the benefit of priority from United Kingdom
patent application No. 12 13794.9, filed on August 2,20 12, the disclosure of which is
incorporated herein in its entirety by reference.
WE CLAIM:
1. A communication node that communicates with a user device over a wireless interface,
the communication node comprising:
5 transceiver circuitry that transmits signals to and receives signals from the user device
using a sequence of sub-frames, each sub-frame comprising a plurality of colnmunication
resource blocks, each resource block corresponding to a sub-band of a system bandwidth used by
the communication node to communicate with the user device and each resource block having a
control portion for carrying first control data and a data portion for carrying user data; and
10 a resource allocatioil module arranged to allocate, within a sub-frame, resource blocks for
communicating with the user device;
wherein the resource allocation module is arranged: i) to generate first resource allocation
data for transmission to the user device, which first resource allocation data allocates a first
plurality of the resource blocks for use in communicating user data with the user device; ii) to
15 allocate at least one resource block for carrying second control data for the user device within the
data portion of the at least one resource block, which at least one resource block is included
within said first plurality of resource blocks allocated by said first resource allocation data; and
iii) to generate second resource allocation data for transmission to the user device that the user
device can use to exclude the at least one resource block carrying said second control data from
20 the first plurality of resource blocks allocated by said first allocation data.
2. A comlnunication node according to claim 1, wherein said second resource allocation
data identifies the at least one resource block for carrying second control data in combination
with the first resource allocation data.
2 5
3. A communication node according to claim 1 or 2, wherein said second resource
allocation data identifies the at least one resource block for carrying second control data relative
to the first plurality of resource blocks allocated by said first resource allocation data.
30 4. A colnmunication node according to any of claims 1 to 3, wherein the plurality of
resource blocks of a sub-frame are arranged in a sequence of resource block groups and wherein
said first resource allocation data allocates the resource blocks within a selected one or more of
said resource block groups.
5. A communication node according to claim 4, wherein the second resource allocation data
comprises a bitmap, wherein the bits within the bitmap correspond to resource blocks within the
selected one or more resource block groups and identify said at least one resource block for
carrying said second control data.
5
6. A communication node according to any of claims 1 to 5, wherein the first allocation data
is arranged to allocate said first plurality of resource blocks as a contiguous group of resource
blocks.
10 7. A communication node according to any of claims 1 to 6, wherein the first allocation data
comprises at least one of: i) a bit map identifying the first plurality of allocated resource blocks,
and ii) data identifying a starting resource block and a number of resource blocks from the
starting resource block that are allocated.
15 8. A communication node according to any of claims 1 to 7, wherein the at least one
resource block is allocated within a known subset of the resource blocks and wherein the second
resource allocation data identifies the at least one resource block with reference to the known
subset.
20 9. A communication node according to claim 8, comprising means for transmitting third
control data to the user device that identifies the subset of resource blocks.
10. A communicatioll node according to claim 9, wherein said means for transmitting is
arranged to transmit the third co~itrodl ata in advance of the communication node transmitting
25 the sub-frame.
11. A communicatioll node according to claim 9, wherein said means for transmitting is
arranged to tra~lsmith e third control data within the sub-frame.
30 12. A communication node according to any of claims 8 to 11, wherein the known subset of
resource blocks is arranged to change from sub-frame to sub-frame.
13. A communication node according to any of claims 1 to 7, wherein the at least one
resource block is allocated within one of a plurality of predefined subsets of resource blocks and
wherein the second resource allocation data identifies one or more of the predefined subsets of
resource blocks containing second control data for exclusion from said plurality of resource
blocks allocated by said first allocation data.
5 14. A com~nuilicationn ode according to claim 13, wherein each predefined subset of
resource blocks has an associated index value and wherein the second control data identifies the
index value associated with the one or more of the predefined subsets of resource blocks
containing second control data.
10 15. A communication node according to any of claims 1 to 14, operable to commuilicate with
a plurality of user devices using said resource bocks and operable to transmit respective second
control data to each user device individually.
16. A communication node according to any of claims 1 to 14, operable to communicate with
15 a plurality of user devices using said resource bocks and operable to broadcast second control
data for all user devices collectively.
17. A con~municationn ode according to claim 15, wherein different second control data is
transmitted to the user devices.
20
18. A communication node according to claim 17, wherein the resource allocation module is
operable to generate respective first allocation data for first and second user devices that define
overlapping resource blocks that are allocated for the first and second user devices and wherein
the resource allocation module is operable to generate different second control data for the first
25 and second user devices to cause each user device to exclude resource blocks to remove the
overlap.
19. A communication node according to any of claims 1 to 18, wherein the first and second
allocation data is transmitted within an enhanced Physical Dowllliilk Control Channel, ePDCCH.
3 0
20. A con~municationn ode according to any of claims 1 to 19, wherein the resource
allocation module is operable to generate first allocatioll data that allocates virtual resource
blocks.
2 1. A user device for communicating with a commui~ication node, the user device
comprising:
transceiver circuitry that transinits signals to and receives signals from the
communication node using a sequence of sub-fiames, each sub-frame comprising a plurality of
5 communication resource blocks, each resource block corresponding to a sub-band of a system
bandwidth of the communication node and each resource block having a control portion for
carrying first control data and a data portion for carrying user data; and
a communication control module tliat is arranged: i) to receive first resource allocation
data, which first resource allocation data allocates a first plurality of the resource blocks for use
10 in communicating user data with the communication node; ii) to receive at least one resource
block that carries second control data for the user device within the data portion of the at least
one resource block, which at least one resource block is included within said first plurality of
resource blocks allocated by said first resource allocation data; iii) to receive second resource
allocation data relating to the at least one resource block carrying said second control data; and
15 iv) to exclude the at least one resource block carrying said second control data from the first
plurality of resource blocks allocated by said first allocation data.
22. A user device according to claim 2 1, wherein said communication control module is
arranged to use the second resource allocation data in combinatioli with the first resource
20 allocation data to identify the at least one resource block that carries the second control data.
23. A user device according to claim 21 or 22, wherein said second resource allocation data
identifies the at least one resource block that carries tlie second control data relative to the first
plurality of resource blocks allocated by said first resource allocation data.
2 5
24. A user device according to any of clai~ns2 1 to 23, wherein the plurality of resource
bloclcs of a sub-frame are arranged in a sequence of resource block groups and wherein said first
resource allocation data allocates tlie resource blocks within a selected one or more of said
resource block groups.
3 0
25. A user device according to claim 24, wherein the second resource allocation data
comprises a bitmap, wherein the bits within the bitlnap correspond to resource blocks within the
selected one or more resource block groups and identify said at least one resource bloclc for
carrying said second control data.
26. A user device according to any of claims 21 to 25, wherein the first allocation data
allocates said first plurality of resource blocks as a contiguous group of resource blocks.
5 27. A user device according to ally of claims 21 to 26, wherein the first allocation data
comprises at least one of: i) a bit map identifying the first plurality of allocated resource blocks,
and ii) data identifying a starting resource block and a number of resource blocks from the
starting resource block that are allocated.
10 28. A user device according to any of claims 21 to 27, wherein the at least one resource
block is allocated within a predefined subset of the resource blocks and wherein the second
resource allocation data identifies the at least one resource block with reference to the predefined
subset.
15 29. A user device according to claim 28, comprising means for receiving third control data
that identifies the predefined subset of resource blocks.
30. A user device according to claim 29, wherein said means for receiving is arranged to
receive the third control data in advance of the user device receiving the sub-frame.
2 0
3 1. A user device according to claim 29, wherein said means for receiving is al-sanged to
receive the third control data within the sub-frame.
32. A user device according to any of claims 28 to 3 1, wherein the predefined subset of
25 resource blocks is arranged to change from sub-frame to sub-frame.
33. A user device according to any of claims 21 to 27, wherein the at least one resource
block is allocated within one of a plurality of predefined subsets of resource blocks and wherein
the second resource allocation data identifies one or more of the predefined subsets of resource
30 blocks containing second control data and wherein the commullication colltrol module is
arranged to exclude the resource blocks within the identified predefined subsets from the
plurality of resource blocks allocated by the first allocatioli data.
34. A user device according to claim 33, wherein each predefined subset of resource blocks
has an associated index value and wherein the second control data identifies the index value
associated with the one or more of the predefined subsets of resource blocks containing second
control data.
5 35. A user device according to any of claims 1 to 18, wherein the first and second allocation
data is transmitted within an enhanced Physical Downlink Control Channel, ePDCCH.
36. A method performed within a communication node that communicates with a user device
over a wireless interface, the method comprising:
10 transmitting signals to and receiving signals from the user device using a sequence of
sub-frames, each sub-frame comprising a plurality of communication resource blocks, each
resource block corresponding to a sub-band of a system bandwidth used by the communication
node to communicate with the user device and each resource block having a control portion for
carrying first control data and a data portion for carrying user data; and
allocating, within a sub-frame, resource blocks for communicating with the user device;
wherein the allocating step comprises: i) generating first resource allocation data for
transmission to the user device, which first resource allocation data allocates a first plurality of
the resource blocks for use in communicating user data with the user device; ii) allocating at
least one resource block for carrying second control data for the user device within the data
20 portion of the at least one resource block, which at least one resource block is included within
said first plurality of resource blocks allocated by said first resource allocation data; and iii)
generating second resource allocation data for transmission to the user device that the user
device can use to exclude the at least one resource block carrying said second control data from
the first plurality of resource blocks allocated by said first allocation data.
2 5
37. A method according to claim 36, performed by a comnluliicatioil nodc accordiilg to any
of claims 1 to 20.
38. A method performed by a user device that communicates with a communication node,
30 the method comprising:
transmits signals to and receiving signals from the commurlication node using a sequence
of sub-frames, each sub-frame comprising a plurality of communication resource blocks, each
resource block corresponding to a sub-band of a system bandwidth used by the user device to
communicate with the communication node and each resource block having a control portion for
carrying first control data and a data portion for carrying user data; and
controlling the communication, including: i) receiving first resource allocation data,
which first resource allocation data allocates a first plurality of the resource blocks for use in
communicating user data with the communication node; ii) receiving at least one resource block
5 that carries second control data for the user device within the data portion of the at least one
resource block, which at least one resource block is included within said first plurality of
resource blocks allocated by said first resource allocation data; iii) receiving second resource
allocation data relating to the at least one resource block carrying said second control data; and
iv) excluding the at least one resource block carrying said second control data from the first
10 plurality of resource blocks allocated by said first allocation data.
39. A method according to claim 38, performed by a user device according to any of claims
21 to 35.
15 40. A communication node that communicates with a user device over a wireless interface,
the communication node comprising:
transceiver circuitry that transmits signals to and receives signals from the user device
using a sequence of sub-frames, each sub-frame comprising a plurality of communication
resource blocks, each resource block correspondiilg to a sub-band of a system bandwidth used by
20 the communication node to communicate with the user device;
a communications control module for controlling communications with the user device
and arranged to send control data to the user device in one of a plurality of predefined control
data formats, the control data formats including a plurality of legacy control data formats each
comprising a different number of bits and one or more new control data formats that each have
25 the same number of bits as a legacy control data format; and
a resource allocation module arranged to generate resource allocation data that allocates,
within a sub-frame, resource bloclcs for communicating with the user device;
wherein the communications control module is arranged to include the resource
allocation data within a selected one of the predefined control data formats and in the case that
30 the resource allocation data has been included within a control data format that has the same
number of bits as another control data format, is arranged to signal additional control data to the
user device to indicate which control data format has been signalled.
41. A communication node according to claim 40, wherein the coinmunication control
module is arranged to signal the additional control data to the user device within the control data
format.
42. A communication node according to claim 40, wherein the communication colltrol
5 module is arranged to signal the additional control data to the user device within another
different control data format.
43. A comlnunication node according to any of claims 40 to 42,
wherein the resource allocation data of a first legacy control data format includes:
a field that is used to indicate a selected resource block group subset froin among a
plurality of resource block group subsets; and
a field that includes a bitmap, where each bit of the bitmap addresses a single resource
block in the selected resource block group subset;
wherein the resource allocation data of a first new control data format has the same
15 number of bits as the first legacy coiltrol data format and includes:
a field that is used to indicate a selection of one out of K partitions of a system bandwidth
of the communication node, where each bandwidth part contains contiguous resource blocks; and
a field that includes a bitmap, where each bit of the bitmap addresses a single resource
block in the selected bandwidth part and indicates if the addressed resource block is allocated to
20 the user device.
44. A communication node according to any of claims 40 to 42,
wherein the resource allocatiol~d ata of a first legacy control data format includes:
a field that is used to indicate a selected resource block group subset from among a
25 plurality of resource block group subsets; and
a field that includes a bitmap, where each bit of the bitmap addresses a single resource
block in the selected resource block group subset;
wherein the resource allocation data of a first new control data format has the same
number of bits as the first legacy control data format and includes:
3 0 a field that is used to indicate a starting resource block of a partition of resource blocks
within a systein bandwidth of the communication node; and
a lield that includes a bitmap, where each bit of the bitmap addresses a single resource
block in the partition of rcsource blocks and indicates if the resourcc block is allocated to the
user device.
45. A coininuilication node according to claim 44, wherein the field used to indicate a
stai-ting resource block of the first new control data format comprises I"~~(NRI ub)i ts and the
field of the first new control data field that includes the bitinap conlprises Gm '1 - r10g2(NRU)l
5 bits, where NRB is the number of available resource blocks and P defines the number of resource
blocks within each subset.
46. A communication node according to claim 44, wherein the Geld used to indicate a
starting resource block of the first new control data format comprises I"~z(NRB1 )b its and the
10 field of the first new control data field that includes the bitmap comprises lNRB'l bits, where
NRB is the number of available resource blocks and P defines the number of resource blocks
within each subset.
47. A communication node according to claim 43 or 44, wherein the first legacy control data
15 format and the first new control data format further includes a field that indicates if the control
data field is the first legacy control data format or the first new control data format.
48. A user device that communicates with a comnluilication node over a wireless interface,
the user device comprising:
2 0 transceiver circuitry that transmits signals to and receives signals from the
communication node using a sequence of sub-frames, each sub-frame comprising a plurality of
conlmunication resource blocks, each resource block corresponding to a sub-band of a system
bandwidth of the communication node;
a communications control module for controlling cominunications with the
25 cominunicatiorl node and operable:
i) to receive control data from the communication node in one of a plurality of
predefined coiltrol data formats, the control data formats including a plurality of legacy control
data formats each comprising a different number of bits and one or nlore new control data
formats that each have the same number of bits as a legacy control data format, the received
30 coiltrol data comprising resource allocation data that allocates, within a sub-frame, resource
blocks for communicating with the communication node;
ii) in the case that the received control data is ill a coiltrol data for~natth at has the
same number of bits as another control data format, to receive additional control data that
indicates which control data format has been used; and
a control data interpreter module that interprets the received control data format in
accordance with the legacy control data format or in accordance with the new coiltrol data format
5 in dependence upon the received additional control data.
49. A user device according to claim 48, wherein the communication control module is
arranged to receive the additional control data within the control data format.
10 50. A user device according to clai~n4 8, wherein the communication control module is
arranged to receive the additional control data within another different control data format.
5 1. A user device according to any of claims 48 to 50,
wherein the resource allocatioi~d ata of a first legacy control data format includes:
15 a field that is used to indicate a selected resource block group subset from among a
plurality of resource block group subsets; and
a field that includes a bitmap, where each bit of the bitmap addresses a single resource
block in the selected resource block group subset;
wherein the resource allocation data of a first new control data format has the same
20 number of bits as the first legacy control data format and includes:
a field that is used to indicate a selection of one out of K partitions of a system bandwidth
of the communication node, where each bandwidth part contains contiguous resource blocks; and
a field that includes a bitmap, where each bit of the bitmap addresses a single resource
block in the selected bandwidth pal? and indicates if the addressed resource block is allocated to
25 the user device.
52. A user device according to any of claims 48 to 50,
wherein the resource allocation data of a first legacy control data format includes:
a field that is used to indicate a selected resource block group subset from among a
30 plurality of resource block group subsets; and
a field that includes a bitmap, where each bit of the bitmap addresses a single resource
block in the selected resource block group subset;
wherein the resource allocation data of a first new control data format has the same
number of bits as the first legacy control data format and includes:
a field that is used to indicate a starting resource block of a partition of resource blocks
within a system bandwidth of the communication node; and
a field that includes a bitmap, where each bit of the bitmap addresses a single resource
block in the partition of resource blocks and indicates if the resource block is allocated to the
5 user device.
53. A user device according to claim 52, wherein the field used to indicate a starting resource
block of the first new control data format comprises I ' o ~ ~ ( ~ , B ) 1 bits and the field of the first new
control data field that includes the bitmap comprises rNRB p1 -r10g2(NRB1) bits, where NRB is the
10 number of available resource blocks and P defines the number of resource blocks within each
subset.
54. A user device according to claim 52, wherein the field used to indicate a starting resource
block of the first new control data format comprises 1 l o " ( ~ ~ ~1 )b its and the field of the first new
15 control data field that includes the bitmap comprises IN' bits, where NRB is the number of
available resource blocks and P defines the number of resource blocks within each subset.
55. A user device according to claim 5 1 or 52, wherein the first legacy control data format
and the first new control data format further includes a field that indicates if the control data field
20 is the first legacy control data format or the first new control data format.
56. A computer instruction product comprising computer implementable instructions for
causiilg a progralnlnable communication device to become configured as a colllmunication node
according to ally of claims 1 to 20 or 40 to 47 or for causing a programmable user device to
25 become configured as the user device of any of claims 21 to 35 or 48 to 55.