DESC:FORM 2
THE PATENTS ACT, 1970 (39 OF 1970)
&
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

SYSTEM AND METHOD FOR LINK ADAPTATION IN A WIRELESS COMMUNICATION NETWORK

Jio Platforms Limited, an Indian company, having registered address at Office -101, Saffron, Nr. Centre Point, Panchwati 5 Rasta, Ambawadi, Ahmedabad - 380006, Gujarat, India

The following complete specification particularly describes the disclosure and the manner in which it is performed.

TECHNICAL FIELD
[0001] The embodiments of the present disclosure generally relate to the field of wireless communication networks. More particularly, the present disclosure relates to a system and a method for link adaptation in a wireless communication network.
BACKGROUND OF THE INVENTION
[0002] The subject matter disclosed in the background section should not be assumed or construed to be prior art merely due to its mention in the background section. Similarly, any problem statement mentioned in the background section or its association with the subject matter of the background section should not be assumed or construed to have been previously recognized in the prior art.
[0003] In a wireless communication network, a Base Station (BS) performs transmission and reception of a wide variety of data with a User Equipment (UE). A quality of communication between the BS and the UE depends on one or more factors associated with radio channel used for the communication. The one or more factors includes a distance between the BS and UE, an interference in the radio channel, presence of obstacles in path of radio channels, and other environmental factors. Therefore, for efficient communication via radio channels there is a requirement to select the appropriate Modulation and Coding Scheme (MCS) referred to as “link adaptation”.
[0004] In the wireless communication network, Block Error Rate (BLER) is a crucial performance metric for evaluating reliability of data transmission. BLER measures the probability of encountering errors in a block of data during transmission over a communication channel. A lower BLER improves the reliability of data transmission. As the BLER increases, number of retransmissions increases, leading to channel quality degradation. to improve the channel quality and maintain the lower BLER, an optimal MCS is selected.
[0005] The optimal MCS is dynamically selected based on the one or more factors associated with the radio channel. The dynamic selection of the MCS enables dynamic adjustment of modulation scheme, modulation rate, code rate, transmission power, and other channel conditions to maximise data rate in the transmission and reception, while maintaining the quality of service (QOS). The optimal MCS defines the modulation scheme, the modulation rate, the code rate, the transmission power, and other channel conditions for both downlink and uplink transmissions.
[0006] The modulation rate indicates number of bits transmitted per Resource Element (RE) irrespective of whether the bits are useful bits or redundant bits. The redundant bits may be added for Forward Error Correction (FEC). The code rate may be defined as a ratio between useful bits and total transmitted bits. Cumulatively, the MCS is used to determine transmission of useful bits per RE. When the MCS is higher, a greater number of useful bits are transmitted within a symbol of the RE, thereby improving the quality of the radio signal. When the MCS is lower, a smaller number of useful bits are transmitted within the symbol of the RE, thereby degrading the quality of the radio signal. The MCS is selected based on Channel Quality Indicator (CQI) feedback and buffer content.
[0007] Traditional link adaptation schemes like Inner Loop Link Adaptation (ILLA) and Outer Loop Link Adaptation (OLLA) improves estimation of the channel by using the MCS to meet a target criterion such as a target Block Error Rate (BLER).
[0008] In conventional systems, the BS utilizes the OLLA to correct the transmission rate by some offset based on the CQI feedback. Although the OLLA adapts to the appropriate transmission rate with changing channel conditions, it has slower convergence to adapt to the actual transmission rate that UE can handle. FIG. 1 illustrates a slot diagram 100 depicting a link adaptation technique, in accordance with prior art. As illustrated in FIG. 1, the BS may be pre-configured to receive feedback at slot 0 and slot 10. The BS may use the feedback to update a current value of the MCS. Due to processing delay and pre-scheduling delay in Time Division Duplexing (TDD) slots of a channel, the feedback received at slot 0 is applied at a later slot for example, slot 9. The BS may receive another feedback at slot 10. The BS may update the value of the MCS after every feedback without accessing the need for an update. In poor channel conditions, the value of the MCS may be downgraded frequently, leading to reduction in the average value of the MCS.
[0009] The MCS earlier scheduled by the BS for the UE is inaccurate and outdated due to latency caused by propagation delay measured by Transmission Time Intervals (TTIs) between the BS and the UE in a slot of the channel. Additionally, a delay occurs in processing feedback and/or Uplink Control Information (UCI) received by the BS from the UE.
[0010] Therefore, there is a need for an accurate method for link adaptation in the wireless network to improve the efficiency of the wireless communication network.
SUMMARY
[0011] The following embodiments present a simplified summary in order to provide a basic understanding of some aspects of the disclosed invention. This summary is not an extensive overview, and it is not intended to identify key/critical elements or to delineate the scope thereof. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.
[0012] In an embodiment, a method for link adaptation in a wireless communication network is described. The method includes receiving, by a reception module, from a User Equipment (UE), a Hybrid Automatic Repeat Request (HARQ) feedback including a previously scheduled value of Modulation and Coding Scheme (MCS) for downlink transmission. The method further includes comparing, by a comparison module, the previously scheduled value of the MCS with a current value of the MCS in a network node. Further, the method includes determining, by a determination module, whether the previously scheduled value of the MCS is same or different from the current value of the MCS based on a result of the comparison. Furthermore, the method includes performing, by an adaptation module the link adaptation, using the current value of the MCS or an updated value of the MCS, based on the determination whether the previously scheduled value of the MCS is same or different from the current value of the MCS.
[0013] In some aspects of the present disclosure, the method further includes performing, by the adaptation module, the link adaptation using the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is same as the current value of the MCS.
[0014] In some aspects of the present disclosure, the method further includes updating, by the adaptation module, the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is different from the current value of the MCS and performing, by the adaptation module, the link adaptation using the updated value of the MCS.
[0015] In some aspects of the present disclosure, for updating the current value of the MCS, the method further includes increasing, by the adaptation module, the current value of the MCS by a first offset value based on the result of the determination that the previously scheduled value of the MCS is greater than the current value of the MCS, wherein the first offset value corresponds to a number of Acknowledgements (ACK) in the HARQ feedback.
[0016] In some other aspects of the present disclosure, for updating the current value of the MCS, the method includes decreasing, by the adaptation module, the current value of the MCS by a second offset value based on the result of the determination that the previously scheduled value of the MCS is less than the current value of the MCS, wherein the second offset value corresponds to a number of Negative Acknowledgements (NACK) in the HARQ feedback.
[0017] In some aspects of the present disclosure, the method further includes determining, by the determination module, the first offset value based on a weighted factor of the number of ACKs in the HARQ feedback or determining, by the determination module, the second offset value based on the weighted factor of the number of NACKs received in the HARQ feedback.
[0018] In some aspects of the present disclosure, the weighted factor corresponds to a value of the target Block Error Rate (BLER), and the target BLERs is one of a pre-defined BLERs or based on channel conditions.
[0019] In some aspects of the present disclosure, the HARQ feedback is received in at least one of a Physical Downlink Shared Channel (PDSCH) and a Physical Downlink Control Channel (PDCCH).
[0020] In some aspects of the present disclosure, the method further includes skipping, by the adaptation module, updating the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is greater than the current value of the MCS and performing, by the adaptation module, the link adaptation using the current value of the MCS.
[0021] In some aspects of the present disclosure, the method further includes skipping, by the adaptation module, updating the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is less than the current value of the MCS and performing, by the adaptation module, the link adaptation using the current value of the MCS.
[0022] In another embodiment, disclosed is a system for link adaptation in a wireless communication network. The system includes a reception module configured to receive, from a User Equipment (UE), a Hybrid Automatic Repeat Request (HARQ) feedback including a previously scheduled value of Modulation and Coding Scheme (MCS) for downlink transmission. The system further includes a comparison module configured to compare the previously scheduled value of the MCS with a current value of the MCS in a network node. Further, the system includes a determination module configured to determine whether the previously scheduled value of the MCS is same or different from the current value of the MCS based on a result of the comparison. Furthermore, the system includes an adaptation module configured to perform the link adaptation, using the current value of the MCS or an updated value of the MCS, based on the determination whether the previously scheduled value of the MCS is same or different from the current value of the MCS.
[0023] In another embodiment, a method for link adaptation in a wireless communication network is described. The method includes receiving, from a User Equipment (UE), an uplink packet including a Cyclic redundancy Check (CRC) status and a value of a Modulation and Coding Scheme (MCS) for uplink transmission. The method further includes comparing the value of the MCS in the uplink packet with a current value of the MCS in a network node. Further, the method includes determining whether the value of the MCS in the uplink packet is same or different from the current value of the MCS based on a result of the comparison. Furthermore, the method includes performing the link adaptation, using the current value of the MCS or an updated value of the MCS, based on the determination whether the value of the MCS in the uplink packet is same or different from the current value of the MCS.
[0024] In some aspects of the present disclosure, the method further includes performing, by the adaptation module, the link adaptation using the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is same as the current value of the MCS.
[0025] In some aspects of the present disclosure, the method further includes updating, by the adaptation module, the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is different from the current value of the MCS and performing, by the adaptation module, the link adaptation using the updated value of the MCS.
[0026] In some aspects of the present disclosure, for updating the current value of the MCS, the method further includes increasing, by the adaptation module, the current value of the MCS by a third offset value based on the result of the determination that the value of the MCS in the uplink packet is greater than the current value of the MCS, wherein the third offset value corresponds to a number of CRC pass statuses in the uplink packet.
[0027] In some other aspects of the present disclosure, for updating the current value of the MCS, the method includes decreasing, by the adaptation module, the current value of the MCS by a fourth offset value based on the result of the determination that the value of the MCS in the uplink packet is less than the current value of the MCS, wherein the fourth offset value corresponds to a number of CRC fail statuses in the uplink packet.
[0028] In some aspects of the present disclosure, the method further includes determining, by the determination module, the third offset value based on a weighted factor of the number of the CRC pass statuses in the uplink packet or determining, by the determination module, the fourth offset value based on the weighted factor of the number the CRC fail statuses in the uplink packet.
[0029] In some aspects of the present disclosure, the weighted factor corresponds to a value of the target Block Error Rate (BLER), and the target BLERs is one of a pre-defined BLERs or based on channel conditions.
[0030] In some aspects of the present disclosure, the uplink packet is received in at least one of a Physical Uplink Shared Channel (PUSCH) and a Physical Uplink Control Channel (PUCCH).
[0031] In some aspects of the present disclosure, the method further includes skipping, by the adaptation module, updating the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is greater than the current value of the MCS and performing, by the adaptation module, the link adaptation using the current value of the MCS.
[0032] In some aspects of the present disclosure, the method further includes skipping, by the adaptation module, updating the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is less than the current value of the MCS and performing, by the adaptation module, the link adaptation using the current value of the MCS.
[0033] In another embodiment, disclosed is a system for link adaptation in a wireless communication network. The system includes a reception module configured to receive, from a User Equipment (UE), a uplink packet including a Cyclic redundancy Check (CRC) status and a value of a Modulation and Coding Scheme (MCS) for uplink transmission. The system further includes a comparison module configured to compare the value of the MCS in the uplink packet with a current value of the MCS in a network node. Further, the system includes a determination module configured to determine whether the value of the MCS in the uplink packet is same as or different from the current value of the MCS based on a result of the comparison. Furthermore, the system includes an adaptation module configured to perform the link adaptation, using the current value of the MCS or an updated value of the MCS, based on the determination whether the value of the MCS in the uplink packet is same as or different from the current value of the MCS.
BRIEF DESCRIPTION OF DRAWINGS
[0034] Various embodiments disclosed herein will become better understood from the following detailed description when read with the accompanying drawings. The accompanying drawings constitute a part of the present disclosure and illustrate certain non-limiting embodiments of inventive concepts disclosed herein. Further, components and elements shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. For the purpose of consistency and ease of understanding, similar components and elements are annotated by reference numerals in the exemplary drawings.
[0035] FIG. 1 illustrates a slot diagram depicting a link adaptation technique, in accordance with prior art.
[0036] FIG. 2 illustrates a diagram depicting an environment of a wireless communication network, in accordance with an embodiment of the present disclosure.
[0037] FIG. 3 illustrates a block diagram of a system for link adaptation in the wireless communication network, in accordance with an embodiment of the present disclosure.
[0038] FIG. 4 illustrates a slot diagram depicting a link adaptation technique, in accordance with an embodiment of the present disclosure.
[0039] FIG. 5 illustrates a process flow diagram depicting a communication between a Base Station (BS) and a User Equipment (UE) for link adaptation in a downlink channel in the wireless communication network, in accordance with an embodiment of the present disclosure.
[0040] FIG. 6 illustrates a process flow diagram depicting a method for link adaptation in the downlink channel in the wireless communication network, in accordance with an embodiment of the present disclosure.
[0041] FIG. 7 illustrates a process flow diagram depicting a communication between the BS and the UE for link adaptation in an uplink channel in the wireless communication network, in accordance with an embodiment of the present disclosure.
[0042] FIG. 8 illustrates a process flow diagram depicting a method for link adaptation in the uplink channel in the wireless communication network, in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0043] Inventive concepts of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which examples of one or more embodiments of inventive concepts are shown. Inventive concepts may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Further, the one or more embodiments disclosed herein are provided to describe the inventive concept thoroughly and completely, and to fully convey the scope of each of the present inventive concepts to those skilled in the art. Furthermore, it should be noted that the embodiments disclosed herein are not mutually exclusive concepts. Accordingly, one or more components from one embodiment may be tacitly assumed to be present or used in any other embodiment.
[0044] The following description presents various embodiments of the present disclosure. The embodiments disclosed herein are presented as teaching examples and are not to be construed as limiting the scope of the present disclosure. The present disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, including the exemplary design and implementation illustrated and described herein, but may be modified, omitted, or expanded upon without departing from the scope of the present disclosure.
[0045] The following description contains specific information pertaining to embodiments in the present disclosure. The detailed description uses the phrases “in some embodiments” which may each refer to one or more or all of the same or different embodiments. The term “some” as used herein is defined as “one, or more than one, or all.” Accordingly, the terms “one,” “more than one,” “more than one, but not all” or “all” would all fall under the definition of “some.” In view of the same, the terms, for example, “in an embodiment” refers to one embodiment and the term, for example, “in one or more embodiments” refers to “at least one embodiment, or more than one embodiment, or all embodiments.”
[0046] The term “comprising,” when utilized, means “including, but not necessarily limited to;” it specifically indicates open-ended inclusion in the so-described one or more listed features, elements in a combination, unless otherwise stated with limiting language. Furthermore, to the extent that the terms “includes,” “has,” “have,” “contains,” and other similar words are used in either the detailed description, such terms are intended to be inclusive in a manner similar to the term “comprising.”
[0047] In the following description, for the purposes of explanation, various specific details are set forth to provide a thorough understanding of embodiments of the present disclosure. It will be apparent, however, that embodiments of the present disclosure may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features.
[0048] The description provided herein discloses exemplary embodiments only and is not intended to limit the scope, applicability, or configuration of the present disclosure. Rather, the foregoing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing any of the exemplary embodiments. Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it may be understood by one of the ordinary skilled in the art that the embodiments disclosed herein may be practiced without these specific details.
[0049] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein the description, the singular forms "a", "an", and "the" include plural forms unless the context of the invention indicates otherwise.
[0050] The terminology and structure employed herein are for describing, teaching, and illuminating some embodiments and their specific features and elements and do not limit, restrict, or reduce the scope of the present disclosure. Accordingly, unless otherwise defined, all terms, and especially any technical and/or scientific terms, used herein may be taken to have the same meaning as commonly understood by one having ordinary skill in the art.
[0051] The various aspects including the example aspects are now described more fully with reference to the accompanying drawings, in which the various aspects of the disclosure are shown. The disclosure may, however, be embodied in different forms and should not be construed as limited to the aspects set forth herein. Rather, these aspects are provided so that this disclosure is thorough and complete, and fully conveys the scope of the disclosure to those skilled in the art. In the drawings, the sizes of components may be exaggerated for clarity.
[0052] In the present disclosure, various embodiments are described using terms such as extensible radio access network (xRAN), and open-radio access network (O-RAN)) that are commonly used in communication standards (e.g., 3rd generation partnership project (3GPP), but these are merely examples for description. Various embodiments of the disclosure may also be easily modified and applied to other communication systems.
[0053] Various aspects of the present disclosure to provide a system and a method for performing link adaptation in a communication network efficiently.
[0054] In another aspect of the present disclosure, the system and the method perform the link adaptation by minimizing repetition or incorrect updating of Modulation Coding Scheme (MCS) to improve accuracy.
[0055] In another aspect of the present disclosure, the system and the method for link adaptation leads to efficient resource utilization.
[0056] In another aspect of the present disclosure, the system and the method for link adaptation optimizes convergence of value of Block Error Rates (BLERs) to target Block Error Rates (BLERs).
[0057] In order to facilitate an understanding of the disclosed invention, a number of terms are defined below.
[0058] Physical Downlink Shared Channel (PDSCH) provides a shared data channel for transmitting user data, such as video, audio, or other application data from base station to user equipment.
[0059] Physical Uplink Shared Channel (PUSCH) carries user data from a User Equipment (UE) to a Base Station (BS), enabling UEs to transmit data to the network.
[0060] Physical Downlink Control Channel (PDCCH) carries control information used to manage the transmission on the physical channels, such as resource allocation, power control commands, and scheduling information.
[0061] Physical Uplink Control Channel (PUCCH) is used for transmitting uplink control information from the UE to the BS. The PUCCH carries information such as acknowledgments (ACK/NACK) for received data, scheduling requests, and other control signals.
[0062] Hybrid Automatic Repeat Request (HARQ) is a technique used in communication networks to improve the reliability and efficiency of data transmission. HARQ combines both error detection and correction techniques to ensure that data is accurately transmitted and received by the recipient.
[0063] A Cyclic Redundancy Check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to digital data. CRC is used to detect errors in data transmission. The CRC generates a checksum, which is a fixed-size value derived from the data being transmitted. This checksum is then appended to the data and sent along with it.
[0064] Modulation and Coding Scheme (MCS) is a combination of modulation and coding techniques that work together to increase the data transmission rate while maintaining the quality of the received signal.
[0065] MCS index is a metric based on several parameters of a wireless connection between a client device and a wireless access point, including data rate, channel width, and the number of antennas or spatial streams in the device.
[0066] Link Adaptation (LA) is a dynamic selection of data rate based on estimates/predictions of the instantaneous channel conditions to be experienced by a transmission. The Link Adaptation maximize spectral efficiency, throughput, and reliability while adapting to changing channel conditions and user requirements.
[0067] Block Error Rate (BLER) is defined as the number of erroneous received code blocks/total number of received code blocks.
[0068] The present disclosure relates to link adaptation in a wireless communication network. To optimize performance of a link (alternatively referred to as “channel”) in the wireless communication network, the BS may adapt the MCS transmitted in a downlink channel and/or instructs the UE to adapt the MCS of the BS in an uplink channel. The adaptation of MCS for the uplink and the downlink channel may be performed based on a target BLER. However, discrepancies may arise in adapting values of the MCS in the link due to the pre-scheduling delay and repetitive or incorrect update of the MCS due the processing delay which degrades the accuracy of performing link adaptation. The present disclosure provides methods to improve accuracy of performing the link adaptation.
[0069] In one or more embodiments, the MCS of the downlink channel may be configured by matching a HARQ feedback received from the UE comprising a previously scheduled value of the MCS of the BS with a current value of the MCS.
[0070] In one or more embodiments, the MCS of the uplink channel may be configured by matching a value of the MCS received in an uplink packet with a current value of the MCS.
[0071] FIG. 2 illustrates a diagram depicting an environment of a wireless communication network 200, in accordance with an embodiment of the present invention.
[0072] The wireless communication network 200 includes coverage regions 206-1 to 206-N (hereinafter cumulatively referred to as the coverage region 206). Each coverage region is served by multiple Base Station (BS) 202-1 to 202-N (hereinafter cumulatively referred to as the BS 202). The base stations 202 serves one or more of at least one User Equipment (UE) 204-1 to 204-N (hereinafter cumulatively referred to as the UE 204) in the coverage region 206. The base stations 202 are connected to a network 208 to provide one or more services to the UE 204.
[0073] The BS 202 may be at least one relay, and at least one Distributed Unit (DU). Typically, the BS 202 may be a network infrastructure that provides wireless access to one or more terminals. The BS 202 has coverage defined to be a predetermined geographic area based on the distance over which a signal may be transmitted. The BS 202 may be referred to as, in addition to “base station”, “network nodes”, “access point (AP)”, “evolved NodeB (eNodeB or eNB)”, “5G node (5th generation node)”, “next generation NodeB (gNB)”, “wireless point”, “transmission/reception point (TRP)”, “Radio Access Network (RAN)” or other terms having equivalent technical meanings.
[0074] The UE 204 may be, at least one DU, at least one Mobile Termination (MT) unit, and at least one relay. Typically, the term “user equipment” or “UE” can refer to any component such as “mobile station”, “subscriber station”, “remote terminal”, “wireless terminal”, “receive point”, or “end user device”.
[0075] The network 208 may include suitable logic, circuitry, and interfaces that may be configured to provide several network ports and several communication channels for transmission and reception of data related to operations of various entities of the wireless communication network 200. Each network port may correspond to a virtual address (or a physical machine address) for transmission and reception of the communication data. For example, the virtual address may be an Internet Protocol Version 4 (IPV4) (or an IPV6 address) and the physical address may be a Media Access Control (MAC) address. The network 208 may be associated with an application layer for implementation of communication protocols based on one or more communication requests from the various entities of the wireless communication system 200. The communication data may be transmitted or received via the communication protocols. Examples of the communication protocols may include, but are not limited to, Hypertext Transfer Protocol (HTTP), File Transfer Protocol (FTP), Simple Mail Transfer Protocol (SMTP), Domain Network System (DNS) protocol, Common Management Interface Protocol (CMIP), Transmission Control Protocol and Internet Protocol (TCP/IP), User Datagram Protocol (UDP), Long Term Evolution (LTE) communication protocols, or any combination thereof. In some aspects of the present disclosure, the communication data may be transmitted or received via at least one communication channel of several communication channels in the network 208. The communication channels may include, but are not limited to, a wireless channel, a wired channel, a combination of wireless and wired channel thereof. The wireless or wired channel may be associated with a data standard which may be defined by one of a Local Area Network (LAN), a Personal Area Network (PAN), a Wireless Local Area Network (WLAN), a Wireless Sensor Network (WSN), Wireless Area Network (WAN), Wireless Wide Area Network (WWAN), a metropolitan area network (MAN), a satellite network, the Internet, an optical fiber network, a coaxial cable network, an infrared (IR) network, a radio frequency (RF) network, and a combination thereof. Aspects of the present disclosure are intended to include or otherwise cover any type of communication channel, including known, related art, and/or later developed technologies.
[0076] FIG. 3 illustrates a block diagram of a system 300 for link adaptation in a wireless communication network, in accordance with an embodiment of the present disclosure. As shown in FIG. 3, the system 300 includes the BS 202, the UE 204, and the network 208.
[0077] The BS 202 may include a communication interface 302, a processor 304, and a memory 306 coupled to the processor 304. The processor 304 may control one or more operations of the BS 202. The processor 304 may also be referred to as the CPU. The memory 306 may provide instructions and data to the processor 304 for performing several functions. The memory 306 may include a Random Access Memory (RAM), a Read-Only Memory (ROM), and a portion of the memory 306 may also include Non-Volatile Random Access Memory (NVRAM). The processor 304 may perform logical and arithmetic operations based on instructions stored within the memory 306. The communication interface 302 may allow transmission and reception of data between the BS 202, the UE 204, and the network 208. The communication interface 302 may include a transmitter, a receiver, and a transmit antenna 314 electrically coupled to the transmitter and the receiver of the communication interface 302.
[0078] The UE 204 may include a communication interface 308, a processor 310, and a memory 312 coupled to the processor 310. The processor 310 may control one or more operations of the UE 204. The processor 310 may also be referred to as the CPU. The memory 312 may provide instructions and data to the processor 310 for performing several functions. The memory 312 may include a Random Access Memory (RAM), a Read-Only Memory (ROM), and a portion of the memory 312 may also include Non-Volatile Random Access Memory (NVRAM). The processor 310 may perform logical and arithmetic operations based on instructions stored within the memory 312. The communication interface 308 may allow transmission and reception of data between the BS 202, the UE 204, and the network 208. The communication interface 308 may include a transmitter, a receiver, and a transmit antenna 316 electrically coupled to the transmitter and the receiver of the communication interface 308.
[0079] The communication interfaces 302 and 308 may be configured to enable the processors 304 and 310 to communicate with various entities of the system 300 via the network 208. Examples of the communication interfaces 302 and 308 may include, but are not limited to, a modem, a network interface such as an Ethernet card, a communication port, and/or a Personal Computer Memory Card International Association (PCMCIA) slot and card, an antenna, a radio frequency (RF) transceiver, one or more amplifiers, a coder-decoder (CODEC) chipset, a subscriber identity module (SIM) card, and a local buffer circuit. It will be apparent to a person of ordinary skill in the art that the communication interfaces 302 and 308 may include any device and/or apparatus capable of providing wireless or wired communications between various other entities of the system 300.
[0080] The processors 304 and 310 may include one or more general purpose processors and/or one or more special purpose processors, a microprocessor, a digital signal processor, an application specific integrated circuit, a microcontroller, a state machine, or ay any type of programmable logic array. The processors 304 and 310 may include may include an intelligent hardware device including a general-purpose processor, such as, for example, and without limitation, a Central Processing Unit (CPU), an Application Processor (AP), a dedicated processor, or the like, a graphics-only processing unit such as a Graphics Processing Unit (GPU), a microcontroller, a Field-Programmable Gate Array (FPGA), a programmable logic device, a discrete hardware component, or any combination thereof. The processors 304 and 310 may be configured to execute computer-readable instructions stored in the memories 306 and 312 to cause a central server (not shown) connected to the network 208 to perform various functions.
[0081] The memories 306 and 312 may further include, but not limited to, non-transitory machine-readable storage devices such as hard drives, magnetic tape, floppy diskettes, optical disks, compact disc read-Only Memories (CD-ROMs), and magneto-optical disks, semiconductor memories, such as ROMs, RAMS, programmable read-only memories PROMs), erasable PROMs (EPROMs), electrically erasable PROMs (EEPROMs), flash memory, magnetic or optical cards, or other type of media/machine-readable medium suitable for storing electronic instructions.
[0082] In addition, the memory may, in some examples, be considered a non-transitory storage medium. The "non-transitory" storage medium is not embodied in a carrier wave or a propagated signal. However, the term "non-transitory" should not be interpreted as the memory is non-movable. In some examples, the memory may be configured to store larger amounts of information. In certain examples, a non-transitory storage medium may store data that can, over time, change (e.g., in Random Access Memory (RAM) or cache). The memory may be an internal storage unit or an external storage unit of the server, cloud storage, or any other type of external storage.
[0083] Embodiments of the present technology may be described herein with reference to flowchart illustrations of methods and systems according to embodiments of the technology, and/or procedures, algorithms, steps, operations, formulae, or other computational depictions, which may also be implemented as computer program products. In this regard, each block or step of the flowchart, and combinations of blocks (and/or steps) in the flowchart, as well as any procedure, algorithm, step, operation, formula, or computational depiction can be implemented by various means, such as hardware, firmware, and/or software including one or more computer program instructions embodied in computer-readable program code. As will be appreciated, any such computer program instructions may be executed by one or more computer processors, including without limitation a general-purpose computer or special purpose computer, or other programmable processing apparatus to perform a group of operations comprising the operations or blocks described in connection with the disclosed methods.
[0084] Further, these computer program instructions, such as embodied in computer-readable program code, may also be stored in one or more computer-readable memory or memory devices (for example, the memories 306 and 312) that can direct a computer processor or other programmable processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory or memory devices produce an article of manufacture including instruction means which implement the function specified in the block(s) of the flowchart(s).
[0085] It will further be appreciated that the term “computer program instructions” as used herein refer to one or more instructions that can be executed by the one or more processors (for example, the processors 304 and 310) to perform one or more functions as described herein. The instructions may also be stored remotely such as on a server, or all or a portion of the instructions can be stored locally and remotely.
[0086] In one embodiment, the processor 304 of the BS 202 may comprise one or more modules such as, a reception module 322, a comparison module 324, a determination module 326, an adaptation module 328, and a transmission module (not shown).
[0087] The reception module 322 may be configured to receive, from the UE 204, a feedback in downlink or an uplink packet in uplink. The feedback and the uplink packet may comprise a previously scheduled value of the MCS. The comparison module 324 may be configured to compare the previously scheduled value of the MCS with a current value of the MCS in the BS 202. The determination module 326 may be configured to determine whether the previously scheduled value of the MCS is same or different from the current value of the MCS based on a result of the comparison. The adaptation module 328 may be configured to perform the link adaptation, using the current value of the MCS or an updated value of the MCS, based on the determination whether the previously scheduled value of the MCS is same or different from the current value of the MCS.
[0088] In one embodiment, the processor 310 of the UE 204 may comprise one more modules such as, a transmission module 318 and a reception module 320. The transmission module 318 may be configured to transmit the feedback or the uplink packet to the BS 202. The reception module 320 may be configured to receive the value of MCS from the BS 202.
[0089] Although FIG. 2 and FIG. 3 illustrate one example of the system 200, various changes may be made to FIG. 2 and FIG. 3. For example, the system 200 may include any number of BS 202 and UE 204 in any suitable arrangement. Further, in another example, the system 300 may include any number of components in addition to the components shown in FIG. 3. Further, various components in FIG. 2 and FIG. 3 may be combined, further subdivided, or omitted and additional components may be added according to particular needs.
[0090] In some embodiments, the BS 202 may configure time-frequency resources from a resource pool for performing uplink and/or downlink transmission with the UE 204. The configuration of a dedicated resource pool of time-frequency resources may be provided in terms of slots, symbols, or frame over a pre-defined time.
[0091] In some aspects of the present disclosure, the MCS may be defined as a number of useful bits which can be carried by one symbol. A symbol may be defined as Resource Element (RE) and the MCS may be defined as how many useful bits can be transmitted per RE. The MCS may depend on radio signal quality in wireless link. When the signal quality is better, the MCS may be higher resulting in transmission of more useful bits within the symbol. When the signal quality is bad, the MCS may be lower resulting in transmission of less useful data within the symbol.
[0092] The MCS may depend on the BLER. BLER is a measure of the reliability of the wireless link and may be calculated based on a ratio of number of erroneous blocks to total number of blocks transmitted. The BLER may be maintained by a predefined threshold value, for example the threshold value may be 10%. A target BLER of 10% may indicate that the UE 204 should receive at least 90% successful transmission from the BS 202. If the target is less than 10% then more re-transmission might be required and cause radio resource consumption. In varying radio conditions, to maintain the BLER within the predefined threshold value, the BS 202 may use link adaptation algorithms to allocate the MCS for uplink and downlink transmissions. The allocated MCS may be signalled to the UE 204 using Uplink Control Information (UCI) and Downlink Control Information (DCI) over a channel.
[0093] In some embodiments, the link adaptation may be performed by the BS 202 based on measured Signal to Interference and Noise Ratio (SINR) which is used for selecting the MCS for transmissions. In some instances, the measured SINR may be inaccurate due to measurement errors, rounding errors due to quantization of the SINR values, and delay from time of measurement until the actual data transmissions. To compensate for SINR inaccuracies, the SINR may be adjusted by a certain offset value before being used for link adaptation and scheduling. The offset value may be adaptively adjusted for each UE 204 based on the feedback obtained from the UE 204.
[0094] FIG. 4 illustrates a slot diagram 400 depicting a link adaptation technique, in accordance with an embodiment of the present disclosure. As illustrated in FIG. 4, the BS 202 may receive feedback in Time Division Duplexing (TDD) slots of the channel. The feedback may be the HARQ for the downlink channel or the uplink packet for the uplink channel. In conventional link adaptation techniques, the feedback may be applied at a later slot for example, slot 9, due to processing and scheduling delay. This may lead to incorrect update of the MCS, and errors may occur in decoding the data transmitted in the channel.
[0095] In some embodiments, the reception module 322 of the BS 202 may receive the MCS in the feedback at slot 0 of the TDD slot and may apply Link Adaptation (LA) based on the received MCS at slot 4 of the TDD slot. Once the BS 202 receives another feedback at slot 10, the comparison module 324 of the BS 202 may compare a current value of the MCS with the MCS value received in the feedback. If the determination module 326 of the BS 202 determines that the current value of the MCS and the MCS value received in the feedback are the same, then the adaptation module 328 of the BS 202 may use the BLER based link adaptation without updating the current value of the MCS. The adaptation module 328 of the BS 202 may perform link adaptation at slot 11 by using the current value of the MCS.
[0096] In some aspects of the present disclosure, if the determination module 326 of the BS 202 determines that the current value of the MCS and the MCS value received in the feedback are different, then the adaptation module 328 of the BS 202 may use the BLER based link adaptation after updating the current value of the MCS. The adaptation module 328 of the BS 202 may perform link adaptation at slot 11 by using the updated value of the MCS.
[0097] In some aspects of the present disclosure, if the determination module 326 of the BS 202 determines that the MCS value received in the feedback is greater than the current value of the MCS, then the adaptation module 328 of the BS 202 may either increase the current value of the MCS or use the same current value of the MCS to perform BLER based link adaptation.
[0098] In some aspects of the present disclosure, if the determination module 326 of the BS 202 determines that the MCS value received in the feedback is lesser than the current value of the MCS, then the adaptation module 328 of the BS 202 may decrease the current value of the MCS or use the same current value of the MCS to perform BLER based link adaptation.
[0099] In some embodiments, during downlink transmission in a Physical Downlink Shared Channel (PDSCH) and/or a Physical Downlink Control Channel (PDCCH), the HARQ feedback may be reported by the UE 204 to determine if the MCS to be used to guarantee a target BLERs has changed during transmission. The target BLERs may be pre-defined BLERs and may vary based on given channel conditions.
[0100] The HARQ feedback may comprise an Acknowledgment (ACK) and a Non-Acknowledgment (NACK) in a slot of a plurality of slots of the PDSCH or the PDCCH, to indicate transmission at a higher target Block Error Rates (BLERs). The target BLERs may also be determined as a ratio of ACKs and NACKs. Based on the HARQ feedback, an offset value may be continuously adapted aiming to converge a current value of the BLERs to the pre-defined target BLERs. The offset value may be pre-configured or assigned based on the target BLER.
[0101] The ACK for a previous transmission may indicate that the last transmission was successful at the current value of the BLERs, and the offset value may be increased by a pre-defined positive constant. The NACK for a previous transmission may indicate that the last transmission was unsuccessful at the current value of the BLERs, and the offset value may be decreased by a pre-defined negative constant. The offset value may be added to the current value of the MCS to ensure that a current value of the BLERs achieved in the downlink channel is closer to the target BLERs.
[0102] FIG. 5 illustrates a process flow diagram 500 depicting a communication between the BS 202 and the UE 204 for link adaptation in a downlink channel in the wireless communication network, in accordance with an embodiment of the present disclosure.
[0103] At block 502, the reception module 322 of the BS 202 may receive the HARQ feedback from the transmission module 318 of the UE 204. The HARQ feedback may be received in the PDSCH or the PDCCH. The HARQ feedback may be mapped to the previously scheduled value of the MCS for the downlink channel used for the UE 204. The previously scheduled value of the MCS may be indicated by the ACK or the NACK for a previous transmission performed successfully or unsuccessfully at current BLERs.
[0104] At block 504, the comparison module 324 of the BS 202 may compare the previously scheduled value of the MCS with the current value of the MCS in the BS 202. The determination module 326 of the BS 202 may determine if the previously scheduled value of the MCS reported by the UE 204 matches with the current value of the MCS in the BS 202. If the determination module 326determine that the previously scheduled value of the MCS is same as the current value of the MCS, then the current value of the MCS may be used by the BS 202 for further transmissions.
[0105] For example, if the target BLER is 10 %, a ratio of step-up and step-down is pre-configured as 1:10. The value of MCS may be updated aggressively upon receiving the ACK in the HARQ feedback and the value of MCS may be downgraded slowly upon receiving the NACK in the HARQ feedback. In conventional methods, the downgrading of the value of the MCS occurs frequently, leading to decrease in average value of the MCS. Hence, to increase the average value of the MCS, the value of the MCS is slowly downgraded upon receiving the NACK in the HARQ feedback.
[0106] At block 506, if the determination module 326determine that the previously scheduled value of the MCS is greater than the current value of the MCS, then only the ACK received in the HARQ feedback may be considered for stepping up the current value of the MCS by a first offset value or a positive offset value. The positive offset value may be determined by a weighted factor of number of ACKs received in the HARQ feedback in the plurality of slots. The weighted factor may be pre-configured or based on the value of the target BLERs. In a non-limiting example, the BS 202 may use 2500Mhz frequency spectrum of a TDD carrier to perform downlink communication. The BS 202 may use the current value of the MCS equal to 24. The value of the MCS may be based on a type of modulation used by the BS 202. The value of the MCS for the 2500 MHz frequency spectrum may not be greater than or equal to 25. Hence, if the value of the MCS may be updated only if the value is lesser than 25. When the BS 202 receive one ACK in the HARQ feedback, the weighted factor for each ACK may be +1. When the BS 202 receives 3 ACKs, the weighted factor may be +3. The first offset value may be +3. Hence, the first offset value may be added to the current value of the MCS to update the value of the MCS. The BS 202 may step-up the value of the MCS to 25. The value of the MCS to be used by the UE 204 may be updated with a stepped-up value of the MCS for further transmissions. The adaptation module 328 of the BS 202 may perform link adaptation by using the updated value of the MCS.
[0107] In another aspect, if the determination module 326 determine that the previously scheduled value of the MCS is greater than the current value of the MCS, then the current value of the MCS may not be updated and the HARQ feedback may be ignored. In a non-limiting example, the BS 202 may use the current value of the MCS equal to 25. When the BS 202 receives 3 ACKs in the HARQ feedback, the first offset value may be +1. The BS 202 may have to step-up the value of the MCS to 26. However, since the value of the MCS for the 2500 MHz frequency spectrum is not updated more than 25, the BS 202 may use the current value of the MCS as 25 instead of updating the value of the MCS. The adaptation module 328 of the BS 202 may perform link adaptation by using the current value of the MCS.
[0108] Further, if the determination module 326 determine that the previously scheduled value of the MCS is lesser than the current value of the MCS, then only the NACKs received in the HARQ feedback may be considered for stepping down the current value of the MCS by a second offset value or a negative offset value. The negative offset value may be determined by a weighted factor of number of NACKs received in the HARQ feedback in the plurality of slots. The weighted factor may be pre-configured or based on the value of the target BLERs. In a non-limiting example, the BS 202 may use the current value of the MCS equal to 25. When the BS 202 receive one NACK in the HARQ feedback, the weighted factor for each NACK may be -0.1 (pre-configured). When the BS 202 receives 10 NACKs, the weighted factor may be -1, due to the ratio 1:10 between the ACK and the NACK received in the HARQ feedback. The second offset value may be -1. The second offset value may be subtracted from the current value of the MCS to update the value of the MCS. The BS 202 may step-down the value of the MCS to 24. The value of the MCS to be used by the UE 204 may be updated with a stepped-down value of the MCS for further transmissions. The adaptation module 328 of the BS 202 may perform link adaptation by using the updated value of the MCS.
[0109] In another aspect, if the determination module 326determine that the previously scheduled value of the MCS is lesser than the current value of the MCS, then the current value of the MCS may not be updated/downgraded and the HARQ feedback may be ignored. In a non-limiting example, the BS 202 may use the current value of the MCS equal to 25. When the BS 202 receives one NACK in the HARQ feedback, the weighted factor for one NACK may be -0.1. The second offset value may be -0.1. As subtracting the second offset value -0.1 from the current value of the MCS may not have significant impact on the current value of the MCS, the BS 202 may use the current value of the MCS as 25 instead of downgrading the value of the MCS. The adaptation module 328 of the BS 202 may perform link adaptation by using the current value of the MCS.
[0110] FIG. 6 illustrates a process flow diagram depicting a method 600 for link adaptation in the downlink channel in the wireless communication network, in accordance with an embodiment of the present disclosure. The method 600 comprises a series of operation steps indicated by blocks 602 through 608.
[0111] At block 602, the processor 304 may be configured to receive, from the UE 204, the HARQ feedback including a previously scheduled value of MCS for downlink transmission. At block 604, the processor 304 may be configured to compare the previously scheduled value of the MCS with a current value of the MCS in the BS 202. At block 606, the processor 304 may be configured to determine whether the previously scheduled value of the MCS is same or different from the current value of the MCS based on a result of the comparison. At block 608, the processor 304 may be configured to perform the link adaptation, using the current value of the MCS or an updated value of the MCS, based on the determination whether the previously scheduled value of the MCS is same or different from the current value of the MCS.
[0112] In some embodiments of the present disclosure, the processor 304 may be configured to perform the link adaptation using the current value of the MCS based on the result of the determination that the previously scheduled value of the MCS is same as the current value of the MCS.
[0113] In some embodiments of the present disclosure, the processor 304 may be configured to update the current value of the MCS based on the result of the determination that the previously scheduled value of the MCS is different from the current value of the MCS and perform the link adaptation using the updated value of the MCS.
[0114] In some embodiments of the present disclosure, for updating the current value of the MCS, the processor 304 may be configured to increase the current value of the MCS by a first offset value based on the result of the determination that the previously scheduled value of the MCS is greater than the current value of the MCS. The first offset value may correspond to a number of Acknowledgements (ACK) in the HARQ feedback.
[0115] In some embodiments of the present disclosure, for updating the current value of the MCS, the processor 304 may be configured to decrease the current value of the MCS by a second offset value based on the result of the determination that the previously scheduled value of the MCS is less than the current value of the MCS. The second offset value may correspond to a number of NACKs in the HARQ feedback.
[0116] In some embodiments of the present disclosure, the processor 304 may be configured to determine the first offset value based on a weighted factor of the number of ACKs in the HARQ feedback. Further, the processor 304 may be configured to determine the second offset value based on the weighted factor of the number of NACKs received in the HARQ feedback. The weighted factor may correspond to a value of the target BLERs.
[0117] In some embodiments of the present disclosure, the processor 304 may be configured to perform the link adaptation using the current value of the MCS by skipping updating the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is greater than the current value of the MCS.
[0118] In some embodiments of the present disclosure, the processor 304 may be configured to perform the link adaptation using the current value of the MCS by skipping updating the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is less than the current value of the MCS.
[0119] In another embodiment, during uplink transmission in a Physical Uplink Control Channel (PUCCH)/ a Physical Uplink Shared Channel (PUSCH), an uplink packet may be received by the BS 202 to determine if the MCS to be used to guarantee the target BLER has changed between transmissions. The target BLERs may be pre-defined BLERs and may vary based on given channel conditions.
[0120] The uplink packet may include a value of the MCS and a Cyclic Redundancy Check (CRC) information/ status in a slot of plurality of slots of the PUSCH or the PUCCH, to indicate transmission at a higher target BLERs. Based on the CRC status, an offset value may be continuously adapted aiming to converge a current value of the BLERs to the pre-defined target BLERs. A CRC pass status for a previous transmission may indicate that the last transmission was successful at the current value of the BLERs, and the offset value may be increased by a pre-defined positive constant. A CRC failure status for a previous transmission may indicate that the last transmission was unsuccessful at the current value of the BLERs, and the offset value may be decreased by a pre-defined negative constant. The offset value may be added to the current value of the MCS to ensure that a current value of the BLERs achieved in the downlink channel is closer to the target BLERs.
[0121] FIG. 7 illustrates a process flow diagram 700 depicting a communication between the BS 202 and the UE 204 for link adaptation in an uplink channel in the wireless communication network, in accordance with an embodiment of the present disclosure.
[0122] At block 702, the reception module 322 of the BS 202 may receive the uplink packet including the CRC information and the value of the MCS from the UE 204. The CRC information may be received in the PUSCH or the PUCCH. The value of the MCS may be determined based on the pre-defined target BLER.
[0123] At block 704, the comparison module 324 of the BS 202 may compare the received value of the MCS with the current value of the MCS in the BS 202. The determination module 326 of the BS 202 may determine if the value of the MCS reported by the UE 204 matches with the current value of the MCS in the BS 202. If the determination module 326determine that the received value of the MCS is same as the current value of the MCS, then the current value of the MCS may be used by the BS 202 for further transmissions.
[0124] In a non-limiting example, if the target BLER is 10 %, a ratio of step-up and step-down is pre-configured as 1:10. The value of MCS may be updated aggressively upon receiving the CRC pass status in the uplink packet and the value of MCS may be downgraded slowly upon receiving the CRC fail status in the uplink packet. To increase the average value of the MCS, the value of the MCS is slowly downgraded upon receiving the CRC fail status in the uplink packet.
[0125] At block 706, if the determination module 326 determine that the received value of the MCS is greater than the current value of the MCS, then only CRC pass status received may be considered for stepping up the current value of the MCS by a third offset value or a positive offset value. The positive offset value may be determined by a weighted factor of number of CRC pass status received in the plurality of slots. The weighted factor may be pre-configured or based on the value of the target BLERs. In a non-limiting example, the BS 202 may use 2500Mhz frequency spectrum of the TDD carrier to perform uplink communication. The BS 202 may use the current value of the MCS equal to 24. The value of the MCS may be based on a type of modulation used by the BS 202. The value of the MCS for the 2500 MHz frequency spectrum may not be greater than or equal to 25. Hence, if the value of the MCS may be updated only if the value is lesser than 25. When the BS 202 receive the CRC pass status in the uplink packet, the weighted factor for CRC pass may be +1. The third offset value may be +1. The third offset value may be added to the current value of the MCS to update the value of the MCS. The BS 202 may step-up the value of the MCS to 25. The value of the MCS to be used by the UE 204 may be updated with a stepped-up value of the MCS for further transmissions. The adaptation module 328 of the BS 202 may perform link adaptation by using the updated value of the MCS.
[0126] In another aspect, if the determination module 326determine that the received value of the MCS is greater than the current value of the MCS, then the current value of the MCS may not be updated. In a non-limiting example, the BS 202 may use the current value of the MCS equal to 25. When the BS 202 receives the CRC pass status in the uplink packet, the third offset value may be +1. The BS 202 may have to step-up the value of the MCS to 26. However, since the value of the MCS for the 2500 MHz frequency spectrum is not updated more than 25, the BS 202 may use the current value of the MCS as 25 instead of updating the value of the MCS. The adaptation module 328 of the BS 202 may perform link adaptation by using the current value of the MCS.
[0127] At block 708, if the determination module 326 determine that the value of the MCS is lesser than the current value of the MCS, then only CRC failure status received may be considered for stepping down the current value of the MCS by a fourth offset value or a negative offset value. The negative offset value may be determined by a weighted factor of number of CRC failure status in the plurality of slots. The weighted factor may be pre-configured or based on the value of the target BLERs. In a non-limiting example, the BS 202 may use the current value of the MCS equal to 25. When the BS 202 receive CRC fail status in the uplink packet, the weighted factor for each transmission may be -0.1 (pre-configured). To increase the average value of the MCS, the BS 202 may use the current value of the MCS for at least ten transmissions. After 10 transmissions, if the BS 202 receives the CRC fail status in the uplink packet, the weighted factor may be -1 due to the ratio 1:10 between the CRC pass and the CRC fail received in the uplink packet. The fourth offset value may be -1. The fourth offset value may be subtracted from the current value of the MCS to update the value of the MCS. The BS 202 may step-down the value of the MCS to 24. The value of the MCS to be used by the UE 204 may be updated with a stepped down value of the MCS for further transmissions. The adaptation module 328 of the BS 202 may perform link adaptation by using the updated value of the MCS.
[0128] In another aspect, if it is determined by the BS 202 that the received value of the MCS is lesser than the current value of the MCS, then the current value of the MCS may not be updated. In a non-limiting example, the BS 202 may use the current value of the MCS equal to 25. When the BS 202 receives the CRC fail status in the uplink packet, the weighted factor may be -0.1. The fourth offset value may be -0.1. As subtracting the fourth offset value from the current value of the MCS may not have significant impact on the current value of the MCS, the BS 202 may use the current value of the MCS as 25 instead of downgrading the value of the MCS. The adaptation module 328 of the BS 202 may perform link adaptation by using the current value of the MCS.
[0129] FIG. 8 illustrates a process flow diagram depicting a method 800 for link adaptation in the uplink channel in the wireless communication network, in accordance with an embodiment of the present disclosure. The method 800 comprises a series of operation steps indicated by blocks 802 through 808.
[0130] At block 802, the processor 304 may be configured to receive, from the UE 204, the uplink packet including the CRC status and a value of MCS for uplink transmission. At block 804, the processor 304 may be configured to compare the value of the MCS in the uplink packet with a current value of the MCS in a network node. At block 806, the processor 304 may be configured to determine whether the value of the MCS in the uplink packet is same or different from the current value of the MCS based on a result of the comparison. At block 608, the processor 304 may be configured to perform the link adaptation, using the current value of the MCS or an updated value of the MCS, based on the determination whether the value of the MCS in the uplink packet is same or different from the current value of the MCS.
[0131] In some embodiments of the present disclosure, the processor 304 may be configured to perform the link adaptation using the current value of the MCS based on the result of the determination that the value of the MCS in the uplink packet is same as the current value of the MCS.
[0132] In some embodiments of the present disclosure, the processor 304 may be configured to update the current value of the MCS based on the result of the determination that the value of the MCS in the uplink packet is different from the current value of the MCS and perform the link adaptation using the updated value of the MCS.
[0133] In some embodiments of the present disclosure, for updating the current value of the MCS, the processor 304 may be configured to increase the current value of the MCS by a third offset value based on the result of the determination that the value of the MCS in the uplink packet is greater than the current value of the MCS. The third offset value may correspond to a number of CRC pass statuses in the uplink packet.
[0134] In some embodiments of the present disclosure, for updating the current value of the MCS, the processor 304 may be configured to decrease the current value of the MCS by a fourth offset value based on the result of the determination that the value of the MCS in the uplink packet is less than the current value of the MCS. The fourth offset value may correspond to a number of CRC fail statuses in the uplink packet.
[0135] In some embodiments of the present disclosure, the processor 304 may be configured to determine the third offset value based on a weighted factor of the number of the CRC pass statuses in the uplink packet. Further, the processor 304 may be configured to determine the fourth offset value based on the weighted factor of the number the CRC fail statuses in the uplink packet.
[0136] In some embodiments of the present disclosure, the processor 304 may be configured to perform the link adaptation using the current value of the MCS by skipping updating the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is greater than the current value of the MCS.
[0137] In some embodiments of the present disclosure, the processor 304 may be configured to perform the link adaptation using the current value of the MCS by skipping updating the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is less than the current value of the MCS.
[0138] Referring to the technical abilities and advantageous effect of the present disclosure, operational advantages that may be provided by one or more embodiments may include providing the system and the method enable link adaptation based on the MCS for both the downlink and the uplink channels to improve accuracy of the link adaptation and to improve the efficiency of the wireless communication network. Another potential advantage of the one or more embodiments may include efficient resource utilization and optimized convergence of value of BLERs to target BLERs. As the link adaptation is performed based on the target BLER, the downgrading of the value of the MCS is slow, leading to increased average value of the MCS and preventing frequent degradation of the value of the MCS in the network. The stability in the network is improved due to maintenance of the same MCS value for continuous transmissions.
[0139] Those skilled in the art will appreciate that the methodology described herein in the present disclosure may be carried out in other specific ways than those set forth herein in the above disclosed embodiments without departing from essential characteristics and features of the present invention. The above-described embodiments are therefore to be construed in all aspects as illustrative and not restrictive.
[0140] The drawings and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein. Any combination of the above features and functionalities may be used in accordance with one or more embodiments.
[0141] In the present disclosure, each of the embodiments has been described with reference to numerous specific details which may vary from embodiment to embodiment. The foregoing description of the specific embodiments disclosed herein may reveal the general nature of the embodiments herein that others may, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications are intended to be comprehended within the meaning of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and is not limited in scope.
LIST OF REFERENCE NUMERALS
[0142] The following list is provided for convenience and in support of the drawing figures and as part of the text of the specification, which describe innovations by reference to multiple items. Items not listed here may nonetheless be part of a given embodiment. For better legibility of the text, a given reference number is recited near some, but not all, recitations of the referenced item in the text. The same reference number may be used with reference to different examples or different instances of a given item. The list of reference numerals is:
100 - Slot diagram depicting a link adaptation technique in prior art
200 - Wireless communication network
202 - Base Station (BS)
202-1 to 202-N - One or more BSs
204 - User Equipment (UE)
204-1 to 204-N -One or more UEs
206-1 to 206-N - Coverage region
208 - Network
300 - Block diagram of a system for link adaptation 302 - Communication interface of the BS 202
304 - Processor of the BS 202
306 - Memory of the BS 202
308 - Communication interface of the UE 204
310 - Processor of the UE 204
312 - Memory of the UE 204
314 - Transmit antenna of the BS 202
316 - Transmit antenna of the UE 204
318 - Transmission module of the UE 204
320 - Reception module of the UE 204
322 - Reception module of the BS 202
324 - Comparison module of the BS 202
326 - Determination module of the BS 202
328 - Adaptation module of the BS 202
400 - Slot diagram depicting a link adaptation technique
500 - Process flow diagram for link adaptation in a downlink channel
502-506 - Operation steps of the process flow diagram 500
600 - Method for link adaptation in the downlink channel
602-608 - Operation steps of the method 600
700 - Process flow diagram for link adaptation in an uplink channel
702-708 - Operation steps of the process flow diagram 700
800 - Method for link adaptation in the uplink channel
802-808 - Operation steps of the method 800
,CLAIMS:We Claim:
1. A method (600) for link adaptation in a wireless communication network, the method (600) comprising:
receiving (602), by a reception module (322) from a User Equipment (UE) (204), a Hybrid Automatic Repeat Request (HARQ) feedback including a previously scheduled value of Modulation and Coding Scheme (MCS) for downlink transmission;
comparing (604), by a comparison module (324), the previously scheduled value of the MCS with a current value of the MCS in a network node (202);
determining (606), by a determination module (326), whether the previously scheduled value of the MCS is same or different from the current value of the MCS based on a result of the comparison; and
performing (608), by an adaptation module (328), the link adaptation, using the current value of the MCS or an updated value of the MCS, based on the determination whether the previously scheduled value of the MCS is same or different from the current value of the MCS.

2. The method (600) as claimed in claim 1, further comprising performing, by the adaptation module (328), the link adaptation using the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is same as the current value of the MCS.

3. The method (600) as claimed in claim 1, further comprising:
updating, by the adaptation module (328), the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is different from the current value of the MCS; and
performing, by the adaptation module (328), the link adaptation using the updated value of the MCS.

4. The method (600) as claimed in claim 3, wherein, for updating the current value of the MCS, the method (600) further comprises at least one of:
increasing, by the adaptation module (328), the current value of the MCS by a first offset value based on the result of the determination that the previously scheduled value of the MCS is greater than the current value of the MCS, wherein the first offset value corresponds to a number of Acknowledgements (ACK) in the HARQ feedback; or
decreasing, by the adaptation module (328), the current value of the MCS by a second offset value based on the result of the determination that the previously scheduled value of the MCS is less than the current value of the MCS, wherein the second offset value corresponds to a number of Negative Acknowledgements (NACK) in the HARQ feedback.

5. The method (600) as claimed in claim 4, further comprising at least one of:
determining, by the determination module (326), the first offset value based on a weighted factor of the number of ACKs in the HARQ feedback; or
determining, by the determination module (326), the second offset value based on the weighted factor of the number of NACKs received in the HARQ feedback.

6. The method (600) as claimed in claim 5, wherein the weighted factor corresponds to a value of the target Block Error Rate (BLER), and the target BLERs is one of a pre-defined BLERs or based on channel conditions.

7. The method (600) as claimed in claim 1, wherein the HARQ feedback is received in at least one of a Physical Downlink Shared Channel (PDSCH) and a Physical Downlink Control Channel (PDCCH).

8. The method (600) as claimed in claim 1, further comprising:
skipping, by the adaptation module (328), updating the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is greater than the current value of the MCS; and
performing, by the adaptation module (328), the link adaptation using the current value of the MCS.

9. The method (600) as claimed in claim 1, further comprising:
skipping, by the adaptation module (328), updating the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is less than the current value of the MCS; and
performing, by the adaptation module (328), the link adaptation using the current value of the MCS.

10. A system (300) for link adaptation in a wireless communication network, the system (300) comprising:
a reception module (322) configured to receive, from a User Equipment (UE) (204), a Hybrid Automatic Repeat Request (HARQ) feedback including a previously scheduled value of Modulation and Coding Scheme (MCS) for downlink transmission;
a comparison module (324) configured to compare the previously scheduled value of the MCS with a current value of the MCS in a network node (202);
a determination module (326) configured to determine whether the previously scheduled value of the MCS is same or different from the current value of the MCS based on a result of the comparison; and
an adaptation module (328) configured to perform the link adaptation, using the current value of the MCS or an updated value of the MCS, based on the determination whether the previously scheduled value of the MCS is same or different from the current value of the MCS.

11. The system (300) as claimed in claim 10, wherein the adaptation module (328) is further configured to perform the link adaptation using the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is same as the current value of the MCS.

12. The system (300) as claimed in claim 10, wherein the adaptation module (328) is further configured to:
update the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is different from the current value of the MCS; and
perform the link adaptation using the updated value of the MCS.

13. The system (300) as claimed in claim 12, wherein, for updating the current value of the MCS, the adaptation module (328) is further configured to:
increase the current value of the MCS by a first offset value based on the result of the determination that the previously scheduled value of the MCS is greater than the current value of the MCS, wherein the first offset value corresponds to a number of Acknowledgements (ACK) in the HARQ feedback; or
decrease the current value of the MCS by a second offset value based on the result of the determination that the previously scheduled value of the MCS is less than the current value of the MCS, wherein the second offset value corresponds to a number of Negative Acknowledgements (NACK) in the HARQ feedback.

14. The system (300) as claimed in claim 13, wherein the determination module (326) is further configured to:
determine the first offset value based on a weighted factor of the number of ACKs in the HARQ feedback; or
determine the second offset value based on the weighted factor of the number of NACKs received in the HARQ feedback.

15. The system (300) as claimed in claim 14, wherein the weighted factor corresponds to a value of the target Block Error Rate (BLER), and the target BLERs is one of a pre-defined BLERs or based on channel conditions.

16. The system (300) as claimed in claim 10, wherein the HARQ feedback is received in at least one of a Physical Downlink Shared Channel (PDSCH) and a Physical Downlink Control Channel (PDCCH).

17. The system (300) as claimed in claim 10, wherein the adaptation module (328) is further configured to:
skip updating the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is greater than the current value of the MCS; and
perform the link adaptation using the current value of the MCS.

18. The system (300) as claimed in claim 10, wherein the adaptation module (328) is further configured to:
skip updating the current value of the MCS based on a result of the determination that the previously scheduled value of the MCS is less than the current value of the MCS; and
perform the link adaptation using the current value of the MCS.

19. A method (800) for link adaptation in a wireless communication network, the method (800) comprising:
receiving (802), by a reception module (322) from a User Equipment (UE) (204), an uplink packet including a Cyclic redundancy Check (CRC) status and a value of a Modulation and Coding Scheme (MCS) for uplink transmission;
comparing (804), by a comparison module (324), the value of the MCS in the uplink packet with a current value of the MCS in a network node (202);
determining (806), by a determination module (326), whether the value of the MCS in the uplink packet is same or different from the current value of the MCS based on a result of the comparison; and
performing (808), by an adaptation module (328) the link adaptation, using the current value of the MCS or an updated value of the MCS, based on the determination whether the value of the MCS in the uplink packet is same or different from the current value of the MCS.

20. The method (800) as claimed in claim 19, further comprising performing, by the adaptation module (328), the link adaptation using the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is same as the current value of the MCS.

21. The method (800) as claimed in claim 19, further comprising:
updating, by the adaptation module (328), the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is different from the current value of the MCS; and
performing, by the adaptation module (328), the link adaptation using the updated value of the MCS.

22. The method (800) as claimed in claim 21, wherein, for updating the current value of the MCS, the method (800) further comprises at least one of:
increasing, by the adaptation module (328), the current value of the MCS by a third offset value based on the result of the determination that the value of the MCS in the uplink packet is greater than the current value of the MCS, wherein the third offset value corresponds to a number of CRC pass statuses in the uplink packet; or
decreasing, by the adaptation module (328), the current value of the MCS by a fourth offset value based on the result of the determination that the value of the MCS in the uplink packet is less than the current value of the MCS, wherein the fourth offset value corresponds to a number of CRC fail statuses in the uplink packet.

23. The method (800) as claimed in claim 22, further comprising at least one of:
determining, by the determination module (326), the third offset value based on a weighted factor of the number of the CRC pass statuses in the uplink packet; or
determining, by the determination module (326), the fourth offset value based on the weighted factor of the number the CRC fail statuses in the uplink packet.

24. The method (800) as claimed in claim 23, wherein the weighted factor corresponds to a value of the target Block Error Rate (BLER), and the target BLERs is one of a pre-defined BLERs or based on channel conditions.

25. The method (800) as claimed in claim 19, wherein the uplink packet is received in at least one of a Physical Uplink Shared Channel (PUSCH) and a Physical Uplink Control Channel (PUCCH).

26. The method (800) as claimed in claim 19, further comprising:
skipping, by the adaptation module (328), updating the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is greater than the current value of the MCS; and
performing, by the adaptation module (328), the link adaptation using the current value of the MCS.

27. The method (800) as claimed in claim 19, further comprising:
skipping, by the adaptation module (328), updating the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is less than the current value of the MCS; and
performing, by the adaptation module (328), the link adaptation using the current value of the MCS.

28. A system (300) for link adaptation in a wireless communication network, the system (300) comprising:
a reception module (322) configured to receive, from a User Equipment (UE) (204), a uplink packet including a Cyclic redundancy Check (CRC) status and a value of a Modulation and Coding Scheme (MCS) for uplink transmission;
a comparison module (324) configured to compare the value of the MCS in the uplink packet with a current value of the MCS in a network node (202);
a determination module (326) configured to determine whether the value of the MCS in the uplink packet is same as or different from the current value of the MCS based on a result of the comparison; and
an adaptation module (328) configured to perform the link adaptation, using the current value of the MCS or an updated value of the MCS, based on the determination whether the value of the MCS in the uplink packet is same as or different from the current value of the MCS.

29. The system (300) as claimed in claim 28, wherein the adaptation module (328) is further configured to perform the link adaptation using the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is same as the current value of the MCS.

30. The system (300) as claimed in claim 28, wherein the adaptation module (328) is further configured to:
update the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is different from the current value of the MCS; and
perform the link adaptation using the updated value of the MCS.

31. The system (300) as claimed in claim 30, wherein, for updating the current value of the MCS, the adaptation module (328) is further configured to:
increase the current value of the MCS by a third offset value based on the result of the determination that the value of the MCS in the uplink packet is greater than the current value of the MCS, wherein the third offset value corresponds to a number of CRC pass statuses in the uplink packet; or
decrease the current value of the MCS by a fourth offset value based on the result of the determination that the value of the MCS in the uplink packet is less than the current value of the MCS, wherein the fourth offset value corresponds to a number of CRC fail statuses in the uplink packet.

32. The system (300) as claimed in claim 31, wherein the determination module (326) is further configured to:
determine the third offset value based on a weighted factor of the number of the CRC pass statuses in the uplink packet; or
determine the fourth offset value based on the weighted factor of the number the CRC fail statuses in the uplink packet.

33. The system (300) as claimed in claim 32, wherein the weighted factor corresponds to a value of the target Block Error Rate (BLER), and the target BLERs is one of a pre-defined BLERs or based on channel conditions.

34. The system (300) as claimed in claim 28, wherein the uplink packet is received in at least one of a Physical Uplink Shared Channel (PUSCH) and a Physical Uplink Control Channel (PUCCH).

35. The system (300) as claimed in claim 28, wherein the adaptation module (328) is further configured to:
skip updating the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is greater than the current value of the MCS; and
perform the link adaptation using the current value of the MCS.

36. The system (300) as claimed in claim 28, wherein the adaptation module (328) is further configured to:
skip updating the current value of the MCS based on a result of the determination that the value of the MCS in the uplink packet is less than the current value of the MCS; and
perform the link adaptation using the current value of the MCS.