FEEDBACK INFORMATION
IN A MULTI-CARRIER WIRELESS TELECOMMUNICATIONS NETWORK
FIELD OFTHE INVENTION
The present invention relates to a method of encoding and transmitting feedback
information in a multi-carrier wireless telecommunications network, a network node
operable to carry out that method and a computer program product.
BACKGROUND
Single carrier wireless telecommunications systems are known. In those known systems,
radio coverage is provided to user equipment, for example, mobile telephones, by
geographical area. A base station is located in each geographical area to provide
the required radio coverage. User equipment in the area served by a base station
receives information and data from the base station and transmits information and
data to the base station. In a high speed downlink packet access (HSDPA)
telecommunications network, data and information is sent between user equipment
and a base station in data packets on a radio frequency carrier.
Information and data transmitted by the base station to the user equipment occurs on
radio frequency carriers known as downlink carriers. Information and data transmitted
by user equipment to the base station occurs on radio frequency carriers known a s
uplink carriers.
In known wireless telecommunication systems operating in single carrier mode, user
equipment can move between geographical base station coverage areas. Service
provided to user equipment is overseen by a radio network controller (RNC). The radio
network controller communicates with user equipment and base stations and
determines which base station each user equipment is primarily connected to.
Furthermore, a radio network controller acts to control and communicate with a base
station and user equipment when user equipment moves from the geographical area
served by one base station to a geographical area served by another base station.
It has been proposed to allow base stations and user equipment to each transmit
simultaneously on more than one carrier. Furthermore it has been proposed to allow
user equipment and base stations to receive simultaneously on more than one carrier
frequency. Each carrier, both uplink and downlink, is typically independently power
controlled and independently scheduled by a base station. Provision of more than one
downlink carrier, for example, on four frequency carriers, allows for a n increase in data
throughput to the user equipment. Networks having more than two carriers may be
referred to as u ti cell high speed downlink packet access" (MC-HSDPA) networks.
The term "multi-carrier" network used herein is envisaged to cover the case where two,
three, four, or more downlink (or uplink) carriers are provided for in a network.
Provision of multi-carrier functionality may have associated problems. Accordingly, it is
desired to improve the operation of a wireless telecommunications network having
multi-carrier functionality.
SUMMARY
Accordingly, a first aspect provides a method of encoding and transmitting feedback
information from a first network node to a second network node in a multi-carrier
wireless telecommunications network, the first network node being operable to:
receive signals from the second network node on two or more reception carriers, each
reception carrier being transmitted within as associated radio band, and
transmit data to the second network node on one or more transmission carriers,
the method comprising the steps of:
0) monitoring for a signal on at least two of the reception carriers;
00 generating feedback information for at least two of said reception carriers based
upon received signals;
( i) grouping the feedback information for reception carriers being transmitted within
the same radio band; and encoding the grouped feedback information for two or
more reception carriers being transmitted within the same radio band; and
(iv) transmitting the encoded feedback information to the second network node on
one or more transmission carriers.
It will be appreciated that in a multiple downlink carrier wireless telecommunications
network feedback is likely to be required for each downlink carrier provided. Such
feedback may, for example, comprise: acknowledgement feedback for a n
implemented acknowledgement protocol, channel quality indicators (CQI), and precoding
control indicators (PCI) used to indicate suitable transmission parameters for the
data transmissions on each downlink carriers. It will be understood that such feedback
can help to ensure that the network operates efficiently. For example, the feedback
associated with utilising a data transmission regime in which an acknowledgement
protocol is operating enables erroneously-decoded data packets, or transport blocks
of data, to be retransmitted, and enables transmission of redundant data packets, or
transport blocks of data, to be minimised. Feedback information in such a protocol (in
the form of an ACK or NACK) can inform the network of whether a data packet is
successfully received and, if a n acknowledgement of successful receipt is fed back
and received, there is no need to re-send that data packet. Conversely, if a negative
acknowledgement is fed back and received, a data packet can be re-sent. Protocols
of the HARQ (Hybrid Automatic Repeat Request) types are examples of such a n
acknowledgement protocol.
In a HSDPAsystem operating in single carrier mode, necessary feedback information
relating to downlink carriers is signalled in a n uplink carrier. The feedback information is
signalled on a known format of a n uplink signalling channel known as the High-Speed
Dedicated Physical Control Channel (HS-DPCCH).
HS-DPCCH formats may use a spreading factor 256 channelisation code. Such a
format allows 10 bits per 0.666ms timeslot. Those HS-DPCCH formats may allow a n
uplink HS-DPCCH channel on a n uplink carrier to carry feedback for up to 2 downlink
carriers by multiplexing the relevant control information for the two carriers into the
available bits of the SF256 code.
For HSDPAsystems capable of operating in a multi-carrier mode, more than two
downlink carriers may be provided. It will be appreciated that in multi-carrier HSDPA
networks, the number of downlink carriers may not match the number of uplink carriers,
or the number of uplink HS-DPCCH channels. Furthermore, the number of downlink
carriers provided may not be exactly double the number of uplink carriers or uplink HSDPCCH
channels provided.
Each uplink, or transmission, carrier may comprise one or more data channels on which
feedback may be transmitted. Feedback information according to the first aspect
may be transmitted to said second network node on one or mare transmission channels
of one or more transmission carriers.
The first aspect recognises that techniques for providing carrier feedback in a multicarrier
network may suffer disadvantages.
For example, possibilities to carry feedback in a 4 downlink carrier system include use of
a SF128 code channel. Such a SF128 channelisation code channel provides 20 bits per
timeslot and therefore may allow for the mapping of all required feedback information
into a single HS-DPCCH channel of a single uplink carrier. Such a n arrangement suffers
the disadvantage of requiring new multiplexing and coding formats. As a result,
implementation using existing system architecture and processes may be complex.
An alternative possibility is the use of multiple SF256 code channels. According to such
a scheme, a rule is required to determine how to map feedback corresponding to
each downlink carrier onto HS-DPCCHs provided by one or more uplink carrier.
Furthermore, in view of the disadvantages associated with using a single SF1 28 code
channel, the use of multiple SF256 code channels may be preferred when more than
two downlink carriers are provided.
The first aspect recognises that a rule implementing use of SF256 spreading code
channels for a multi-carrier system may advantageously take into account that
different downlink carriers may be activated and deactivated dynamically.
In a multi-carrier system there may be provided N downlink carriers. Those downlink
carriers may be denoted by: C(l), C(2) ...C(n)... to C(N). In such a system there may
also be provided and a set of HS-DPCCHs. Those dedicated data channels may be
provided on a single uplink carrier, or may be provided on one or more uplink carriers.
Each available HS-DPCCH is denoted by: H(l), H(2)...H(m)... H(M) (where M may be
equal to N/2 since each HS-DPCCH may carry feedback for 2 downlink carriers).
If M=N/2, one possibility regarding a mapping rule for implementing use of a SF256
spreading code is to map feedback for downlink carrier C(n) to HS-DPCCH H((n/2))
where (n/2) here denotes rounding up to the nearest integer (the "ceiling" function).
However, that mapping rule may result in the use of more HS-DPCCH codes than are
strictly necessary. For example: if N=4 and C(2) and C(3) are deactivated, then
according to such a rule, two HS-DPCCHs will be required. A more efficient rule may
take account of carrier activation. Use of more HS-DPCCHs than required has the
disadvantage of increasing the cubic metric (CM) of the transmitted signal and
therefore implementation costs. Such a rule also fails to take into account that the
different carriers may be in different frequency bands with possibly different coverage
areas, and experiencing different radio condition.
The first aspect recognises that it may be beneficial to map feedback corresponding to
downlink carriers in a single band to the same HS-DPCCH. For example, if C(l) and C(3)
are in one band, while C(2) and C(4) are in another band, the first aspect recognises
that it may be better to map the feedback for C(l) and C(3) to H(l) and the feedback
for C(2) and C(4) to H(2).
According †o the first aspect mapping of carrier feedback to HS-DPCCHs first groups
feedback corresponding to carriers in the same band. In some embodiments that
grouping may be a pairing. Pairing may be particularly advantageous when utilising a
SF256 spreading code.
In one embodiment N=6 and carriers C(l), C(2), C(3) and C(6) are activated and C(4)
and C(5) are deactivated, where C(l) and C(3) are in the same band. In this
embodiment a grouping and feedback reporting system according to the first aspect
may act to map C(l) and C(3) to H(l), C(2) to 1-1(2) and C(6) to 1-1(3). It will be
appreciated that according to the first aspect the radio band within which a downlink
carrier is being transmitted is determinative. Accordingly, C(4) would also be mapped
to 1-1(2) and C(5) to 1-1(3) but since they are not activated, no feedback is transmitted.
In one embodiment step (i) comprises the steps of receiving a n indication of activated
reception carriers and monitoring for a signal on at least one of those activated
reception carriers.
In one embodiment a mapping rule further takes into account the activated carriers.
Thus feedback is first grouped or paired according to those downlink carriers being
transmitted within the same radio band, and then grouped or paired according to
which carriers are currently activated. In one embodiment N=6 and carriers C(l ),
C(2), C(3) and C(6) are activated, where C(l) and C(3) are in the same band. This
embodiment maps C(l) and C(3) to H(l), and C(2) and C(6) to H(2).
In one embodiment step ( i) comprises grouping said feedback information for
activated reception carriers being transmitted within the same radio band; and
encoding said grouped feedback information for two o r more activated reception
carriers being transmitted within the same radio band.
It will be appreciated that a signal may not be received in respect of a reception
carrier and that feedback information generated in respect of such a reception carrier
may reflect that no signal has been received.
In one embodiment step is carried out only for those reception carriers on which a
signal is received.
In one embodiment the first network node comprises user equipment and the second
network node comprises a base station.
A second aspect provides a computer program product operable, when executed on
a computer, to perform the method steps described in relation to the first aspect.
A third aspect provides a network node adapted to encode and transmit feedback
information to a second network node in a multi-carrier wireless telecommunications
network, the network node being operable to:
receive signals from the second network node on two or more reception carriers, each
reception carrier being transmitted within an associated radio band, and
transmit data to the second network node on one or more transmission carriers,
the network node comprising:
0) monitoring logic operable to monitor for a signal on at least two of the reception
carriers;
(ii) feedback information generation logic operable to generate feedback information
for at least two of said reception carriers based upon received signals;
ii) encoding logic operable to group said feedback information for reception carriers
being transmitted within the same radio band; and encode the grouped feedback
information for two or more reception carriers being transmitted within the same radio
band; and
(iv) transmission logic operable to transmit the encoded feedback information to the
second network node on one or more of the transmission carriers.
In one embodiment the monitoring logic is operable to receive an indication of
activated reception carriers and monitor for a signal on at least one of those activated
reception carriers.
In one embodiment the encoding logic is operable to group the feedback information
for activated reception carriers having the same band; and encode the grouped
feedback information for two or more activated reception carriers being transmitted
within the same radio band.
In one embodiment the feedback information generation logic is operable to
generate feedback information for those reception carriers on which a signal was
received.
In one embodiment the network node comprises user equipment.
In one embodiment the network node comprises a base station.
A further aspect provides a method for associating a plurality of feedback signalling
instances to a plurality of feedback channels, wherein each feedback channel can be
associated with at least two feedback signalling instances, wherein the feedback
signalling instances associated with one feedback channel are first selected such that
the feedback signalling instances correspond to radio signals received in the same
band.
In one embodiment, the feedback signalling instances associated with one feedback
channel are secondly selected according to the activation status of the corresponding
radio signals.
A still further aspect provides a method of transmitting feedback information from a first
network node to a second network node in a multi-carrier wireless telecommunications
network, said first network node being operable to:
receive signals from said second network node on three or more reception carriers,
each reception carrier being transmitted within an associated radio band, and
transmit data to said second network node on two or more transmission channels,
said method comprising the steps of:
0) monitoring for a signal on each of said reception carriers;
generating feedback information for each reception carrier based upon
received signals;
Oii) grouping said feedback information for at least two reception carriers being
transmitted
within the same radio band; and
Ov) transmitting said grouped feedback information to said second network
node on one transmission channel.
In one embodiment, the method further comprises the step of: transmitting feedback
information for at least one reception carrier being transmitted within a different band
on a different transmission channel.
In one embodiment, wherein step 0) further comprises the steps of receiving
an indication of activated reception carriers and monitoring for a signal on each of
those activated reception carriers.
In one embodiment, step Oii) comprises grouping the
feedback information for activated reception carriers being transmitted within the
same
radio band.
In one embodiment, the further method further comprises the steps of :
after grouping said feedback information for any reception carriers being transmitted
within the same radio band, grouping further feedback information for at least two
reception carriers being transmitted within different bands; and
transmitting said grouped further feedback information to the second network node on
one transmission channel.
In one embodiment, step (ii) is carried out only for those reception carriers on which a
signal was received.
In one embodiment, the first network node comprises user equipment and the second
network node comprises a base station.
A further aspect provides a network node operable to perform the method of the
further aspects set out above.
A still further aspect provides a computer program product operable, when executed
on a computer, to perform the method of the further aspects set out above.
Further particular and preferred aspects of the present invention are set out in the
accompanying independent and dependent claims. Features of the dependent
claims may be combined with features of the independent claims a s appropriate and
in combinations other than those explicitly set out in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described further, with reference to
the drawings in which:
Figure illustrates the main components of a telecommunications network according
to one embodiment.
DESCRIPTION OFTHE EMBODIMENTS
Figure 1 illustrates a wireless telecommunications system 10 according to one
embodiment. User equipment 50 roam through the wireless telecommunications
system. Base stations 20 are provided which support areas of radio coverage 30. A
number of such base stations 20 are provided and are distributed geographically in
order †o provide a wide area of coverage †o user equipment 50. When user equipment
is within an area served by a base station 30, communications may be established
between the user equipment and the base station over associated radio links. Each
base station typically supports a number of sectors within the geographical area of
service 30.
Typically a different antenna within a base station supports each associated sector.
Accordingly, each base station 20 has multiple antennas and signals sent through the
different antennas are electronically weighted to provide a sectorised approach. Of
course, it will be appreciated that Figure 1 illustrates a small subset of the total number
of user equipment and base stations that may be present in a typical communications
system.
The radio access network of the wireless communications system is managed by a
radio network controller (RNC) 40. The radio network controller 40 controls operation of
the wireless communications system by communicating with a plurality of base stations
over a backhaul communications link 60. The network controller also communicates
with user equipment 50 via each base station.
In HSDPAmulti-carrier mode, each sector served by a base station can have several
carrier frequencies or "carriers" associated therewith. A carrier or cell supported by a
carrier covers the same geographical region as a sector. Each cell is served by a
different carrier frequency. It will therefore be understood that in a single carrier system,
a cell is equivalent to a sector since a sector has only one cell or carrier frequency.
Nonetheless, in a multi-carrier network each sector may comprise several cells each
cell being served simultaneously by a different carrier frequency.
A radio network controller 60 maintains a neighbour list which includes information
about geographical relationships between sectors supported by base stations 20. In
addition, the radio network controller 60 maintains location information which provides
information on the location of user equipment 50 within the wireless communication
system 10. The radio network controller is operable to route traffic via circuit switched
and packet switched networks. Hence, a mobile switching centre is provided with
which the radio network controller may communicate. The mobile switching centre
can communicate with a circuit switched network such as a public switched telephone
network (PSTN) 70. Similarly, a network controller can communicate with service
general package radio service support nodes (SGSNs) and a gateway general packet
support node (GGSN). The GGSN can communicate with a packet switched core such
as for example, the Internet.
User equipment 50 typically transmits information and data to a base station 20 so that
it can be re-routed within a wireless telecommunications network. User equipment
may, for example, need to transmit data to the base station in order to relay text
messages, voice information when a user is using the equipment to make a telephone
call, or other data. The base station 20, in combination with parameters set by the
radio network controller 40, allocates resources to user equipment in a manner that
aims to optimise operation of the wireless telecommunications network 10.
A radio link is a connection between user equipment 50 and a cell of a base station.
Dedicated radio links are formed when user equipment is in a "cell-DCH" state. When
user equipment is not transmitting information such as text messages or voice
information to a base station it is in a so-called "idle" state. When user equipment has
information to transmit to a base station it chooses a connected state within which to
operate. When in a "cell-DCH" state user equipment is able to use high speed uplink
and/or downlink packet access radio resources to achieve a high uplink and/or
downlink throughput.
In a multi-carrier system, each carrier will have independent downlink radio links from a
base station to user equipment. Those downlink radio links are managed
independently since each carrier will likely have different radio propagation paths to
user equipment.
In a wireless telecommunications network operating with multiple downlink carriers,
feedback is likely to be required for each downlink carrier provided. Such feedback
may, for example, comprise: acknowledgement feedback for an implemented
acknowledgement protocol, channel quality indicators (CQI), and pre-coding control
indicators (PCI) used to indicate suitable transmission parameters for the data
transmissions on each downlink carriers. It will be understood that such feedback can
help to ensure that the network operates efficiently. For example, the feedback
associated with utilising a data transmission regime in which an acknowledgement
protocol is operating enables transmission of redundant data packets, or transport
blocks of data to be minimised. Feedback information in such a protocol (in the form
of an ACK or NACK) can inform the network of whether a data packet is successfully
received and, if an acknowledgement of successful receipt is fed back and received.
there is no need to re-send that data packet. Protocols of the HARQ (Hybrid Automatic
Repeat Request) types are examples of such an acknowledgement protocol.
In a system operating with only a single carrier, necessary feedback information relating
to downlink carriers is signalled in a n uplink carrier. The feedback information is
signalled on a known format of a n uplink signalling channel known as the High-Speed
Dedicated Physical Control Channel (HS-DPCCH).
HS-DPCCH formats may use a spreading factor 256 channelisation code. Such a
format allows 0 bits per 0.666ms timeslot. Those HS-DPCCH formats may allow an
uplink carrier to carry feedback for up to 2 downlink carriers by multiplexing the relevant
control information for the two carriers into the available bits of the SF256 code.
For HSDPAsystems capable of operating in multi-carrier mode, more than two downlink
carriers may be provided. It will be appreciated that in a multi-carrier network, the
number of downlink carriers may not match the number of uplink carriers. Furthermore,
the number of downlink carriers provided may not be exactly double the number of
uplink carriers provided.
According to one embodiment, a feedback rule implementing use of a SF256
spreading code for a multi-carrier system may advantageously take into account that
different downlink carriers may be experiencing different radio condition and that
different downlink carriers may be activated and deactivated dynamically.
In a multi-carrier system there may be provided N downlink carriers. Those downlink
carriers may be denoted by: C(l), C(2) ...C(n)... to C(N). In such a system there may
also be provided and a set of HS-DPCCHs. Those dedicated data channels may be
provided on a single uplink carrier, or may be provided on one or more uplink carriers.
Each available HS-DPCCH is denoted by: H(l), H(2)...H(m)... H(M) (where may be
equal to N/2 since each HS-DPCCH may carry feedback for 2 downlink carriers).
For systems where M is chosen to equal to N/2, one possibility regarding a mapping rule
for implementing use of a SF256 spreading code is to map feedback for downlink
carrier C(n) to HS-DPCCH H((n/2)) where (n/2) denotes rounding up to the nearest
integer (the "ceiling" function).
However, that mapping rule may result in the use of more HS-DPCCH codes than are
strictly necessary. For example: if N=4 and C(2) and C(3) are deactivated, then
according to such a rule, two HS-DPCCHs will be required. A more efficient rule may
take account of carrier activation. Use of more HS-DPCCHs than required has the
disadvantage of increasing the cubic metric (CM) of the transmitted signal and
therefore implementation costs. Such a rule also fails to take into account that the
different carriers may be in different frequency bands with possibly different coverage
areas, and experiencing different radio condition.
In one embodiment it is recognised that it may be beneficial to map feedback
corresponding to downlink carriers in a single band to the same HS-DPCCH. For
example, if C(l) and C(3) are in one band, while C(2) and C(4) are in another band,
the first aspect recognises that it may be better to map the feedback for C(l) and C(3)
to H(l) and the feedback for C(2) and C(4) to H(2).
According to one embodiment, mapping of carrier feedback to HS-DPCCHs first groups
feedback corresponding to carriers in the same band. In some embodiments that
grouping may be a pairing. Pairing may be particularly advantageous when utilising a
SF256 spreading code.
In one embodiment, N=6 and carriers C(l), C(2), C(3) and C(6) are activated and C(4)
and C(5) are deactivated, where C(l) and C(3) are in the same band. In this
embodiment a grouping and feedback reporting system according to the first aspect
may act to map C(l) and C(3) to H(l), C(2) to H(2) and C(6) to H(3). It will be
appreciated that, according to the first aspect, the radio band within which a downlink
carrier is being transmitted is determinative. Accordingly, C(4) would also be mapped
to H(2) and C(5) to H(3) but since they are not activated, no feedback is transmitted.
In one embodiment, a mapping rule further takes into account the activated carriers.
Thus feedback is first grouped or paired according to those downlink carriers being
transmitted within the same radio band, and then grouped or paired according to
which carriers are currently activated. In one embodiment, N=6 and carriers C(l ),
C(2), C(3) and C(6) are activated, where C(l) and C(3) are in the same band. This
embodiment maps C(l) and C(3) to H(l), and C(2) and C(6) to H(2).
A person of skill in the art would readily recognize that steps of various above-described
methods can be performed by programmed computers. Herein, some embodiments
are also intended to cover program storage devices, e.g., digital data storage media,
which are machine or computer readable and encode machine-executable or
computer-executable programs of instructions, wherein said instructions perform some
or all of the steps of said above-described methods. The program storage devices may
be, e.g., digital memories, magnetic storage media such as a magnetic disks and
magnetic tapes, hard drives, or optically readable digital data storage media. The
embodiments are also intended to cover computers programmed to perform said
steps of the above-described methods.
The functions of the various elements shown in the Figures, including any functional
blocks labelled as "processors" or "logic", may be provided through the use of
dedicated hardware as well as hardware capable of executing software in association
with appropriate software. When provided by a processor, the functions may be
provided by a single dedicated processor, by a single shared processor, or by a
plurality of individual processors, some of which may be shared. Moreover, explicit use
of the term "processor" or "controller" or "logic" should not be construed to refer
exclusively to hardware capable of executing software, and may implicitly include,
without limitation, digital signal processor (DSP) hardware, network processor,
application specific integrated circuit (ASIC), field programmable gate array (FPGA),
read only memory (ROM) for storing software, random access memory (RAM), and non
volatile storage. Other hardware, conventional and/or custom, may also be included.
Similarly, any switches shown in the Figures are conceptual only. Their function may be
carried out through the operation of program logic, through dedicated logic, through
the interaction of program control and dedicated logic, or even manually, the
particular technique being selectable by the implementer as more specifically
understood from the context.
It should be appreciated by those skilled in the art that any block diagrams herein
represent conceptual views of illustrative circuitry embodying the principles of the
invention. Similarly, it will be appreciated that any flow charts, flow diagrams, state
transition diagrams, pseudo code, and the like represent various processes which may
be substantially represented in computer readable medium and so executed by a
computer or processor, whether or not such computer or processor is explicitly shown.
The description and drawings merely illustrate the principles of the invention. It will thus
be appreciated that those skilled in the art will be able to devise various arrangements
that, although not explicitly described or shown herein, embody the principles of the
invention and are included within its spirit and scope. Furthermore, all examples recited
herein are principally intended expressly to be only for pedagogical purposes to aid the
reader in understanding the principles of the invention and the concepts contributed
by the inven†or(s) to furthering the art, and are to be construed as being without
limitation to such specifically recited examples and conditions. Moreover, all statements
herein reciting principles, aspects, and embodiments of the invention, aswell as
specific examples thereof, are intended to encompass equivalents thereof.
CLAIMS
1. A method of encoding and transmitting feedback information from a first
network node to a second network node in a multi-carrier wireless telecommunications
network, said first network node being operable to:
receive signals from said second network node on two or more reception carriers, each
reception carrier being transmitted within an associated radio band, and
transmit data to said second network node on one or more transmission carriers,
said method comprising the steps of:
0) monitoring for a signal on at least two of said reception carriers;
(ii) generating feedback information for at least two reception carriers based upon
received signals;
(iii) grouping said feedback information for reception carriers being transmitted within
the same radio band; and encoding said grouped feedback information for two or
more reception carriers being transmitted within the same radio band; and
(iv) transmitting said encoded feedback information to said second network node on
one or more transmission carriers.
2. A method according to claim 1, wherein step 0) comprises the steps of
receiving an indication of activated reception carriers and monitoring for a signal on at
least one of those activated reception carriers.
3. A method according to claim 2, wherein step (Hi) comprises grouping said
feedback information for activated reception carriers being transmitted within the
same radio band; and encoding said grouped feedback information for two or more
activated reception carriers being transmitted within the same radio band.
4. A method according to claim 1, wherein step is carried out only for those
reception carriers on which a signal was received.
5. A method according to any preceding claim, wherein said first network node
comprises user equipment and said second network node comprises a base station.
6. A computer program product operable, when executed on a computer, to
perform the method of any one of claims 1to 5 .
7. A network node operable to encode and transmit feedback information to a
second network node in a multi-carrier wireless telecommunications network, said
network node being operable to:
receive signals from said second network node on two or more reception carriers, each
reception carrier being transmitted within a n associated radio band, and
transmit data to said second network node on one or more transmission carriers,
said network node comprising:
0) monitoring logic operable to monitor for a signal on at least two of said reception
carriers;
feedback information generation logic operable to generate feedback information
for at least two of said reception carriers based upon received signals;
Oii) encoding logic operable to group said feedback information for reception carriers
being transmitted within the same radio band; and encode said grouped feedback
information for two or more reception carriers being transmitted within the same radio
band; and
Ov) transmission logic operable to transmit said encoded feedback information to said
second network node on one or more of said transmission carriers.
8. A network node according to claim 7, wherein said monitoring logic is operable
to receive an indication of activated reception carriers and monitor for a signal on at
least one of those activated reception carriers.
9. A network node according to claim 8, wherein said encoding logic is operable
to group said feedback information for activated reception carriers being transmitted
within the same radio band; and encode said grouped feedback information for two
or more activated reception carriers being transmitted within the same radio band.
10. A network node according to claim 7, wherein said feedback information
generation logic is operable to generate feedback information only for those reception
carriers on which a signal was received.
1 . A network node according to any one of claims 7 to 10 wherein said network
node comprises user equipment.
12. A network node according to any one of claims 7 to 10 wherein said network
node comprises a base station.