Channel state information with denoising mechanisms

Abstract

A method, apparatus and computer program is described comprising: receiving configuration information relating to a device of a wireless communication system; determining activation and distribution of channel state information error processing modules based, at least in part, on the received configuration information and setting a channel state information processing mode of operation accordingly; providing a mode of operation message defining a channel state information processing mode of operation for use by the device; and receiving channel state information from the device in accordance with the defined mode of operation.

Description

[0001] CHANNEL STATE INFORMATION WITH DENOISING MECHANISMS

[0002] Field

[0003] The present specification relates to channel state information in wireless communication systems.

[0004] Background

[0005] The present specification relates to channel state information in wireless communication systems. For example, an estimate of channel state information maybe transmitted from a device (e.g. a user device) over a channel of the wireless communication system.

[0006] Summary

[0007] In a first aspect, this specification describes an apparatus (e.g. a network node of the wireless communication system) comprising: means for receiving (e.g. over a channel of a wireless or mobile communication system) configuration information relating to a device of a wireless communication system, said configuration information including channel state information acquisition capabilities of the device (e.g. whether low and / or high complexity modes are available) and channel state information processing modes of operation supported by the device; means for determining activation and distribution of one or more channel state information error processing modules based, at least in part, on the received configuration information and setting a channel state information processing mode of operation accordingly; means for providing a mode of operation message, said mode of operation message defining a channel state information processing mode of operation for use by the device; and means for receiving channel state information (e.g. encoder channel state information) from the device in accordance with the defined mode of operation.

[0008] The channel state information processing modes of operation may include at least one of a first mode, a second mode and a third mode. The first mode may be an energy efficient mode. The second mode maybe a moderate energy mode. The second mode may be a minimal support mode. The third mode may be a high energy mode. The third mode may be a maximal support mode. The channel state information error processing modules may comprise an error detection module that identifies errors in a codeword received from the device over said channel. The channel state information error processing modules may comprise a first error correction module that corrects errors detected in the codeword received from the device over said channel. The channel state information error processing modules may comprise a second error correction module that corrects for errors in a codeword generated at the device resulting from errors in channel estimation.

[0009] Some example embodiments further comprise means for receiving a suggested channel state information processing mode of operation from the device, wherein said mode of operation message includes an indication of whether or not the suggested mode of operation is accepted.

[0010] Some example embodiments further comprise means for rescheduling transmission of channel state information from the device in the event that an error is said channel state information is identified.

[0011] Some example embodiments further comprise means for correcting the received channel state information in the event that an error is said channels state information is identified. In a second aspect, this specification describes a device (e.g. a user device of the mobile communication system) comprising: means for providing, to a network node of a wireless communication system (e.g. over a channel of the wireless communication system), configuration information relating to the device, wherein said configuration information includes channel state information acquisition capabilities of the device and channel state information processing modes of operation supported by the device; means for receiving a mode of operation message from the network node; means for generating channel state information in accordance with a channel state information processing mode of operation defined by the mode of operation message; and means for providing the generated channel state information (e.g. encoded channel state information) to the network node.

[0012] The device may further comprise means for providing a suggested channel state information processing mode of operation to the network node, wherein said mode of operation message includes an indication of whether or not the suggested mode of operation is accepted. The channel state information processing modes of operation may include at least one of a first mode, a second mode and a third mode. The first mode may be an energy efficient mode. The second mode maybe a moderate energy mode. The second mode maybe a minimal support mode. The third mode maybe a high energy mode. The third mode may be a maximal support mode.

[0013] The device may further comprise means for activating and distributing one or more channel state information error processing modules based, at least in part, on said mode of operation message. The channel state information error processing modules may comprise an error detection module that identifies errors in a codeword received from the device over said channel. The channel state information error processing modules may comprise a first error correction module that corrects errors detected in the codeword received from the device over said channel. The channel state information error processing modules may comprise a second error correction module that corrects for errors in a codeword generated at the device resulting from errors in channel estimation.

[0014] Some example embodiments further comprise means for rescheduling transmission of channel state information from the device in the event that an error is said channel state information is identified.

[0015] Some example embodiments further comprise means for correcting the received channel state information in the event that an error is said channels state information is identified.

[0016] In a third aspect, this specification describes a method comprising: receiving (e.g. over a channel of a wireless communication system) configuration information relating to a device of a wireless communication system, said configuration information including channel state information acquisition capabilities of the device and channel state information processing modes of operation supported by the device; determining activation and distribution of one or more channel state information error processing modules based, at least in part, on the received configuration information and setting a channel state information processing mode of operation accordingly; providing a mode of operation message, said mode of operation message defining a channel state information processing mode of operation for use by the device; and receiving channel state information from the device in accordance with the defined mode of operation. The channel state information processing modes of operation may include at least one of a first mode, a second mode and a third mode. The first mode may be an energy efficient mode. The second mode maybe a moderate energy mode. The second mode may be a minimal support mode. The third mode may be a high energy mode. The third mode may be a maximal support mode.

[0017] Some example embodiments further comprise receiving a suggested channel state information processing mode of operation from the device, wherein said mode of operation message includes an indication of whether or not the suggested mode of operation is accepted.

[0018] Some example embodiments further comprise rescheduling transmission of channel state information from the device in the event that an error is said channel state information is identified.

[0019] Some example embodiments further comprise correcting the received channel state information in the event that an error is said channels state information is identified. In a fourth aspect, this specification describes a method comprising: providing, to a network node of a wireless communication system (e.g. over a channel of the wireless communication system), configuration information relating to a device, wherein said configuration information includes channel state information acquisition capabilities of the device and channel state information processing modes of operation supported by the device; receiving a mode of operation message from the network node; generating channel state information in accordance with a channel state information processing mode of operation defined by the mode of operation message; and providing the generated channel state information to the network node. The method may further comprise providing a suggested channel state information processing mode of operation to the network node, wherein said mode of operation message includes an indication of whether or not the suggested mode of operation is accepted. The method may further comprise activating and distributing one or more channel state information error processing modules based, at least in part, on said mode of operation message. Some example embodiments further comprise rescheduling transmission of channel state information from the device in the event that an error is said channel state information is identified.

[0020] Some example embodiments further comprise correcting the received channel state information in the event that an error is said channels state information is identified.

[0021] In a fifth aspect, this specification describes computer-readable instructions which, when executed by a computing apparatus, cause the computing apparatus to perform (at least) any method as described herein (including the methods of the third or fourth aspects described above).

[0022] In a sixth aspect, this specification describes a computer-readable medium (such as a non-transitory computer-readable medium) comprising program instructions stored thereon for performing (at least) any method as described herein (including the methods of the third or fourth aspects described above).

[0023] In a seventh aspect, this specification describes an apparatus comprising: at least one processor; and at least one memory including computer program code which, when executed by the at least one processor, causes the apparatus to perform (at least) any method as described herein (including the method of the third or fourth aspects described above).

[0024] In an eighth aspect, this specification describes an apparatus comprising: at least one processor; and at least one memoiy storing instructions that, when executed by the at least one processor, causes the apparatus to perform (at least) any method as described herein (including the method of the third or fourth aspects described above).

[0025] In a ninth aspect, this specification describes a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to: receive (e.g. over a channel of a wireless communication system) configuration information relating to a device of the wireless communication system, said configuration information including channel state information acquisition capabilities of the device and channel state information processing modes of operation supported by the device; determine activation and distribution of channel state information error processing modules based, at least in part, on the received configuration information and setting a channel state information processing mode of operation accordingly; provide a mode of operation message, said mode of operation message defining a channel state information processing mode of operation for use by the device; and receive channel state information from the device in accordance with the defined mode of operation. In a tenth aspect, this specification describes a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to: provide, to a network node of a wireless communication system (e.g. over a channel of the wireless communication system), configuration information relating to a device, wherein said configuration information includes channel state information acquisition capabilities of the device and channel state information processing modes of operation supported by the device; receive a mode of operation message from the network node; generate channel state information in accordance with a channel state information processing mode of operation defined by the mode of operation message; and provide the generated channel state information to the network node.

[0026] In an eleventh aspect, this specification describes a receiver input (or some other means) for receiving (e.g. over a channel of a wireless communication system) configuration information relating to a device of a wireless communication system, said configuration information including channel state information acquisition capabilities of the device and channel state information processing modes of operation supported by the device; a processor (or some other means) for determining activation and distribution of one or more channel state information error processing modules based, at least in part, on the received configuration information and setting a channel state information processing mode of operation accordingly; a mode controller (or some other means) for providing a mode of operation message, said mode of operation message defining a channel state information processing mode of operation for use by the device; and a / the receiver input (or some other means) for receiving channel state information from the device in accordance with the defined mode of operation. In a twelfth aspect, this specification describes an output (or some other means) for providing, to a network node of a wireless communication system (e.g. over a channel of the wireless communication system), configuration information relating to a device, wherein said configuration information includes channel state information acquisition capabilities of the device and channel state information processing modes of operation supported by the device; an input (or some other means) for receiving a mode of operation message from the network node; a processor (or some other means) for generating channel state information in accordance with a channel state information processing mode of operation defined by the mode of operation message; and a / the output (or some other means) for providing the generated channel state information to the network node.

[0027] Brief description of the drawings

[0028] Example embodiments will now be described, by way of non-limiting examples, with reference to the following schematic drawings, in which: FIGS. 1 to 5 are block diagrams showing systems in accordance with example embodiments;

[0029] FIG. 6 is a flow chart showing an algorithm in accordance with an example embodiment;

[0030] FIGS. 7 and 8 are message flow sequences showing algorithms in accordance with example embodiments;

[0031] FIGS. 9 and 10 are flow charts showing algorithms in accordance with example embodiments;

[0032] FIG. 11 is a schematic diagram of components of one or more of the example embodiments described previously; and FIG. 12 shows tangible media for storing computer-readable code which when run by a computer may perform methods according to example embodiments described herein.

[0033] Detailed description

[0034] The scope of protection sought for various embodiments of the invention is set out by the independent claims. The embodiments and features, if any, described in the specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the invention. In the description and drawings, like reference numerals refer to like elements throughout. FIG. i is a block diagram showing a system, indicated generally by the reference numeral to, in accordance with an example embodiment. The system comprises a device (such as a user equipment (UE)) 12, a channel 14 and a network node 16. The device 12 and the network node 16 are in two-way communication with each other via the channel 14.

[0035] In systems such as the system 10, channel state information (CSI) maybe required for many purposes, such as accurate precoding in massive multiple-input multiple-output (MIMO) communications with frequency division duplex (FDD) schemes. Accurate CSI can be used, for example, to enable a base station (BS) to obtain higher signal-to-noise- ratio (SNR) and to improve channel capacity. However, in many implementations of the system 10 (such as FDD networks), only the device 12 can estimate downlink CSI.

[0036] In such systems, the estimated CSI is typically shared with the network node 16 over the channel 14, which introduces an overhead to the communication system.

[0037] To reduce this overhead, the CSI may be compressed and / or quantized prior to transmission. For example, the CSI data maybe compressed (e.g. using vector quantization) to generate a codebook that achieves a high compression rate (CR), i.e., the ratio of compressed size to uncompressed size. (The compression rate may be a scalar in the range of (o, 1], where a lower CR means more compression.) Alternatively, or in addition, the CSI data may be quantized such that, for example, the device 12 communicates quantized bits over the channel 14, with the network node 16 including a de-quantizer to generate signals that a decoder can use to reconstruct the original channel state information estimate.

[0038] Schemes (such as data compression and / or data quantization) for reducing transmission overheads often limit the accuracy of CSI reconstruction. FIG. 2 is a block diagram showing a system, indicated generally by the reference numeral 20, in accordance with an example embodiment. The system 20 comprises a channel estimator 22, an encoder 24 and a transmitter 26 that are an example implementation of the device 12 described above. The channel estimator 22 can be used to estimate downlink channel state information (CSI). An encoded version of the estimated CSI is transmitted (for example from the device 12 to the network node 16 over the channel 14). FIG. 3 is a block diagram showing a system, indicated generally by the reference numeral 30, in accordance with an example embodiment. The system 30 comprises a receiver 32 and a decoder 34 that are an example implementation of the network node 16 described above. The receiver 32 may receive the encoded CSI data as transmitted by the system 20. The decoder 34 decodes the encoded and transmitted CSI in order to reconstruct the CSI as estimated by the channel estimator 22.

[0039] The encoder 24 and the decoder 34 may together act as an autoencoder (AE), with the encoder 24 being used to generate a compressed representation of the input CSI and the decoder 34 being used to reconstruct the CSI from the compressed information.

[0040] The encoder and decoder of an autoencoder-based CSI compression arrangement may be implemented using artificial intelligence or machine learning models. Such models may be trained in a number of ways, for example:

[0041] • Joint training of the two-sided autoencoder model at a single side / entity, e.g., at the UE / device side or at the network side. This may be referred to a type 1 training.

[0042] • Joint training of the two-sided autoencoder model at the network side and the UE / device side, respectively. This maybe referred to as type 2 training. • Separate training at network side and UE / device side, where the UE / device-side

[0043] CSI generation part and the network-side CSI reconstruction part are trained by the UE / device side and the network side, respectively. This maybe referred to as type 3 training. Joint training may refer to the code generation model (encoder) and the reconstruction model (decoder) being trained in the same loop for forward propagation and backward propagation. Joint training could be implemented at a single node or across multiple nodes (e.g. through gradient exchange between nodes). Separate training typically includes sequential training starting with UE side training, or sequential training starting with network side training at the UE.

[0044] In the system 20, the output of the channel estimator 22 provides an imperfect channel estimation denoted by eCSI as follows: eCSI = CSI + e , Where e±is an error term introduced by the imperfect downlink channel estimation.

[0045] Note that e1is typically the main source of error in CSI feedback.

[0046] The eCSI is then encoded by the encoder 24 (that may form part of an AIML autoencoder) into a bit vector C.

[0047] The code C is prepared for transmission by the transmitter module 26. For example, the code C may undergo a typical OFDM transmission over an uplink control channel (e.g., the bits maybe encoded using Polar codes, modulated onto QAM symbols, and then into an OFDM waveform).

[0048] The transmitted waveform (e.g. an OFDM waveform) travels over a wireless propagation channel (e.g. the channel 14) to the receiver 32 of the system 30. During transmission, the waveform is contaminated by noise and interference. At the receiver 32, the signal may undergo an OFDM reception (using receiver 32), including decoding

[0049] (using decoder 34), so that an estimated code C is produced, where the estimation quality depends on the wireless conditions and the robustness of the transmission scheme:

[0050] Here e2is the error at the input of the decoder 34. In some example embodiments, e2maybe a rare event, due to very high error detection / correction probability using legacy channel coding with CRC check. However, depending on the received signal’s signal-to-noise ratio (SNR) and the considered codelength and code rate for the legacy channel coding, e2may be more frequent. In case e2is available in C, if we manage to correct the received code, there is no need to schedule a retransmission, which results in reducing latency and saving resources.

[0051] The estimated code is decoded by the decoder 34 and a reconstructed eCSI (denoted by eCST) is output. Thus, eCSI is an imperfect estimate of the true CSI, where the imperfections have broadly two causes:

[0052] • DL-based errors due to the imperfect downlink channel estimation in the UE, i.e., the first block of which produces eCSI.

[0053] • UL-based errors e2due to the imperfect uplink OFDM reception which introduces error on the estimated code C in the gNB. The imperfect reconstruction eCSl may be used to select a precoder, where the selection itself may become suboptimal, depending on how inaccurate eCSl ultimately is. To provide an accurate CSI feedback architecture which is relatively agnostic to the severity of channel conditions (in both DL and UL), it is this desirable that the network node 16 reconstructs an accurate version of the CSI.

[0054] FIG. 4 is a block diagram of a system, indicated generally by the reference numeral 40, in accordance with an example embodiment. The system 40 comprises an encoder 42 and a decoder 44 that operate together as an autoencoder. The autoencoder of the system 40 may be used to encoder and decoder of the systems described above.

[0055] The encoder and decoder may further implement a CSI denoising framework in which the denoising mechanisms:

[0056] • can be decoupled from the CSI compression task, and thus do not impact the training or management of the CSI autoencoder; and

[0057] • target correcting errors due to both imperfect channel estimation and UL reception. The CSI denoising framework may include co-ordinating the use of one or more of the following modules between the UE and the gNB:

[0058] • An error detection block (code-EDB) that identifies the errors in the received codeword C. The error detection block is provided to target uplink errors.

[0059] • An error correction block (code-ECB) that corrects the errors in the received codeword C. The error correction block is provided to target uplink errors.

[0060] • A CSI error correction block (CSI-ECB) that corrects the errors introduced by the imperfect DL channel estimation.

[0061] The error detection block (code-EDB) and the error correction block (code-ECB) are provided to target uplink errors. The CSI error correction block is provided to target downlink errors.

[0062] Note that in the code-EDB block, the network may identify the UL errors based on the code-EDB of the decoded CSI codeword that comes after a cyclic redundancy code (CRC) check, i.e., decoded UCI payload with no errors. In one variant, after applying code-EDB, if the CSI codeword is in error, the gNB can reschedule the UL transmission. In another variant, after applying code-EDB, if the CSI codeword is in error, the gNB may consider the code-ECB to correct decoded CSI codeword.

[0063] The code-EDB, code-ECB and CSI-ECB blocks may be combined and integrated with the autoencoder architecture 40 in different ways. For example, one or more of those blocks may be distributed between the device side (e.g. as part of the encoder 42) and one or more of those blocks maybe distributed on the network side (e.g. as part of the decoder 44). Alternatively, the blocks maybe implemented exclusively at the network side.

[0064] Some or all the code-EDB, code-ECB and CSI-ECB blocks can be dynamically switched on / off by the network as part of life cycle management (LCM). The output of one or more of said blocks maybe used as input to the other blocks. FIG. 5 is a block diagram showing a system, indicated generally by the reference numeral 50, in accordance with an example embodiment. In the system 50, error detection and correction modes are all provided on the network side; as noted above, this is not essential to all example embodiments. The system comprises a channel estimator 51, an encoder 52, an OFDM transmitter module 53, a wireless channel 54, an OFDM receiver module 55, a decoder 56, an error detection module 57 and an error correction module 58. The system 50 shows one configuration of error detection and correction blocks. As discussed in detail below, alternative configuration are possible and can be selected and controlled in accordance with the principles described herein.

[0065] The channel estimator 51, encoder 52 and transmitter module 53 are similar to the channel estimator 22, encoder 24 and transmitter 26 and may form part of the device 12 of the system 10 described above. The receiver module 55, decoder 56, error detection module 57 and error correction module 58 may form part of the network node 16 of the system 10 described above.

[0066] The OFDM receiver 55 implements a means for receiving data transmitted by a device (e.g. the device 12) of a wireless communication system over the channel 54 of a wireless communication system. The data encodes a first estimate of a channel state information of the wireless channel as determined at said device (i.e. as determined at the channel estimator 51).

[0067] As described above with reference to the system 20, the channel estimator 51 is an imperfect channel estimator that provides an imperfect channel estimation denoted by eCSI as follows: eCSI = CSI + ex,

[0068] Where eris an error term introduced by the imperfect downlink channel estimation. The eCSI is then encoded by the encoder 52 into a bit vector C.

[0069] The code C is prepared for transmission by the OFDM transmitter module 53. At the OFDM receiver 45, an estimated code C is produced, where the estimation quality depends on the wireless conditions and the robustness of the transmission scheme: C = C + e2,

[0070] The estimated code C is passed through the decoder 56 (which forms a decoder part of an AIML autoencoder with the encoder 42) to produce a reconstructed CSI estimate eCSI which is then sent to an error correction module 58 that aims to remove some or all uplink and downlink error from the reconstructed code.

[0071] The reconstructed code C is also routed to the error detection module 57 which detects the errors in the reconstructed code and outputs a scalar e e [0, 1], where e = 1 if C = C. The error correction module 58 receives:

[0072] • the reconstructed code C output by the OFDM receiver 55;

[0073] • the reconstructed eCSI output by the decoder 56; and

[0074] • the detected error e output by the error detection module 57. The error correction module 58 seeks to remove the uplink and downlink errors discussed above in the reconstructed CSI estimate (eCST) to produce an estimate CSI that closely approaches the true CSI.

[0075] Thus, the decoder 56 decodes generates a second estimate (eCST) of the channel state information of the wireless channel and the error correction module generates a channel state information output (CS7) by modifying the second estimate of the channel state information based, at least in part, on the first error indication (e). The first error indication may be indicative of estimated errors in the first channel state information estimate as generated at the device (i.e. downlink error). Alternatively, or in addition, the first error indication may be indicative of uplink errors introduced in the data transmitted over the wireless connection between the device and the network node.

[0076] It should be noted that although the decoder 56, the error detection module 57 and the error correction module 58 are shown as three separate modules, two or more of those modules could be merged into a single module (e.g. into a single neural network). For example, the error detection module 57 and the error correction module 58 could be integrated. Nevertheless, there maybe advantages to separating the modules, not least as the training of the modules can then be more easily separated. The error correction module 58 may be a neural network or machine learning module that can trained to distinguish between:

[0077] • DL channel estimation errors (at the channel estimation module 51); and

[0078] • UL reception errors. The error detection module 57 (for generating the first error indication) may also be implemented using a neural network or a machine learning module.

[0079] As discussed further below, depending on where error correction and detection blocks are provided, user device can be configured with different operational modes associated to the CSI feedback. These may include:

[0080] • A first mode. The first mode may be an energy efficient mode (EEM). In the first mode, the user device (e.g. using channel estimator 51) may implement low complexity DL channel estimation e.g., assumes high SNR conditions. The user device may implement a simple interpolation / extrapolation to construct CSI at missing entries e.g., without attempting to estimate or harness channel correlation in time / frequency / space domains.

[0081] • A second mode. The second mode may be a moderate energy mode, such as a minimal support mode (mSM). In the second mode, the user device may implement a higher complexity channel estimation (e.g. using channel estimator 51) including SINR estimation and interference cancellation. The user device may implement a CSI reconstruction using estimated time / frequency / space channel correlation. The user device may assist the network side (e.g. gNB) with CSI-ECB configuration; for example the user device may transfer a CSI quality metric together with the CSI feedback.

[0082] • A third mode. The third mode may be a high energy mode, such as a maximal support mode (MSM). In the third mode, the user device may implement some or all of the elements of the second mode (e.g. the minimal support mode (mSM) described above) and additionally applies CSI-ECB prior to encoding.

[0083] FIG. 6 is a flow chart showing an algorithm, indicated generally by the reference numeral 60, in accordance with an example embodiment.

[0084] The algorithm 60 starts at operation 62 where configuration information is reported by a user device to a network node over a channel (e.g. the channel 54) of a wireless communication system. The configuration information includes information such as the channel state information acquisition capabilities of the device and channel state information processing modes of operation supported by the device. For example, the channel state information acquisition capabilities may indicate whether the device can operate in a low complexity mode and / or in a high complexity mode. In one example embodiment, the low complexity mode is a mode without noise or interference cancellation and / or in which reference signals are linearly interpolated to reconstruct missing entries. In one example embodiment, the high complexity mode is a mode with noise and interference cancellation and / or in which Doppler and excess delay estimation is available for enhanced reference signal interpolation for recovering missing entries. Of course, these modes are provided by way of example only. Different modes could be provided (include a different number of modes). The processing modes of operation supported by the device may include one or more of first, second and third modes described above (e.g. an energy efficient mode; a moderate energy or a minimal support mode; and / or a high energy or maximal support mode). Note that one or more of the operational modes may include the requirement that the UE is able to provide assistance for network-side CSI error correction. Then, with the CSI compressed codeword, the UE feedbacks possible error levels of the CSI estimation. For example, the UE may indicate any CSI error levels (e.g., indications such as low / medium / high error levels, or a standard deviation of the CSI estimate) so that the network can use such indication when applying ML models. At operation 64, the network (e.g. the network 16) configures the system. For example, the network may determine activation and distribution of channel state information error processing modules based, at least in part, on the configuration information receives in the operation 62. A channel state information processing mode of operation is set accordingly. The channel state information processing mode of operation may include at least one of: a first mode (e.g. an energy efficient mode); a second mode (e.g. a moderate energy or a minimal support mode); and a third mode (e.g. a high energy or maximal support mode), as discussed above.

[0085] By way of example, the network may configure and combine blocks such as the code- EDB, code-ECB, CSI-ECB described above. Note that if the network can identify residual uplink errors based on the code-EDB of the decoded CSI codeword that comes after the CRC check (e.g. decoded UCI payload with no errors), then in one variant, the network may reschedule the UL transmission and in another variant, the network may consider the code-ECB to correct decoded CSI codeword.

[0086] At operation 66, a mode of operation message is provided by the network to the device. The mode of operation message defines the mode of operation for use by the device (as defined in the operation 64). At operation 68, channel state information (e.g. encoded channel state information) is received at the network from the device in accordance with the mode of operation set in the operation 66. Note that if the code-ECB block is not activated, but the code-EDB block detects residual error, the network may reconfigure the UL transmission and use a more robust MCS.

[0087] With the operation 68 complete, the network may complete the algorithm by deactivating the UE operational mode.

[0088] FIG. 7 is a message flow sequence, indicated generally by the reference numeral 70, showing an algorithm in accordance with an example embodiment. The message flow sequence 70 shows messages transferred between, and actions taken at, a user equipment (UE) 71 and a gNB 72. The UE 71 and gNB 72 are example implementations of the UE 12 and the network node 16 described above. The message flow sequence 70 is an example implementation of the algorithm 60 described above. As shown in the sequence 70, one or more messages 73 are sent from the UE 71 to the gNB 72. The messages 73 include reports indicating CSI acquisition capabilities of the UE 71 (e.g. whether the low and high complexity modes discussed above are supported) and modes of operation supported by the UE 71 (e.g. whether the first, second or third modes discussed above are supported).

[0089] At operation 74, the gNB 72 distributes CSI processing blocks such as the code-EDB, code-ECB, CSI-ECB block described above. As discussed above, the CSI processing blocks may include one or more of: an error detection module that identifies errors in a codeword received from the device over said channel; a first error correction module that corrects errors detected in the codeword received from the device over said channel; and a second error correction module that corrects for errors in a codeword generated at the device resulting from errors in channel estimation.

[0090] The gNB 72 sends a message 75 to the UE 71 defining the CSI processing mode of operation to be implemented at the UE. The modes may include the first, second or third modes discussed above.

[0091] The defined CSI processing mode of operation is then implemented at the UE 71 in operation 76. The operation 76 includes generating channel state information in accordance with the defined mode of operation.

[0092] At operation 77, obtained (and, for example, encoded) channel state information is communicated to the gNB 72 in accordance with the mode of operation implemented in the operation 76.

[0093] With the operation 77 complete, the gNB sends a message 78 deactivating the selected UE operational mode.

[0094] FIG. 8 is a message flow sequence, indicated generally by the reference numeral 80, showing an algorithm in accordance with an example embodiment. The message flow sequence 80 shows messages transferred between, and actions taken at, a user equipment (UE) 81 and gNB 82 (which are similar to, and may be identical to, the UE 71 and gNB 72 described above). The message flow sequence 70 is an alternative implementation of the algorithm 60 described above. As shown in the sequence 80, one or more messages 83 are sent from the UE 81 to the gNB 82. The messages 83 include reports indicating CSI acquisition capabilities of the UE 81 (e.g. whether the low and high complexity modes discussed above are supported) and modes of operation supported by the UE 81 (e.g. whether the first, second or third modes discussed above are supported). The message(s) 83 may be identical to the message(s) 73 described above.

[0095] At operation 84, the UE 81 sends a message 84 to the gNB requesting that the EEM mode of operation be used. (Note that the message 84 could, in some example embodiments, include a request for a different mode of operation to be used, such as the minimal or maximal support modes discussed above.)

[0096] At operation 85, the gNB 82 distributes CSI processing blocks such as the code-EDB, code-ECB, CSI-ECB block described above. The gNB 82 sends a message 86 to the UE 81 indicating whether the request included in the message 84 is accepted and / or indicating which CSI processing mode of operation is to be implemented at the UE. The modes may include the first, second and third modes discussed above. The defined CSI processing mode of operation is then implemented at the UE 81 in operation 87. The operation 87 includes generating channel state information in accordance with the defined mode of operation.

[0097] At operation 88, obtained (and, for example, encoded) channel state information is communicated to the gNB 82 in accordance with the mode of operation implemented in the operation 87.

[0098] With the operation 88 complete, the gNB sends a message 89 deactivating the selected UE operational mode. Thus, in the message sequence 80, the UE may be the one requesting an operational mode, with the gNB accepting and configuring said mode, or conversely rejecting the mode. Such situation may occur when the UE itself temporarily needs to transition to an energy saving model, or when the UE has learnt (e.g., from current DL detection) that channel conditions are favourable (e.g., high SL SINR), therefore a low complexity mode is sufficient for a successful CSI feedback.

[0099] As discussed above, example embodiments may include blocks for detecting and correcting errors in channel state information.

[0100] Figure 9 is a flow chart showing an algorithm, indicated generally by the reference numeral 90, in accordance with an example embodiment. The algorithm 90 starts at operation 92, where an error in a channel state error is detected (e.g. using the code- EDB block discussed above). At operation 94 of the algorithm 90, the error is corrected (or at least partially corrected) in response to the identification of the error. The error maybe corrected using the code-ECB and / or the CSI-ECB blocks described above.

[0101] Figure 10 is a flow chart showing an algorithm, indicated generally by the reference numeral too, in accordance with an example embodiment. The algorithm too starts at operation 102, where an error in a channel state error is detected (e.g. using the code-

[0102] EDB block discussed above). At operation 104 of the algorithm too, transmission of channel state information from the device is rescheduled in response to the identification of the error. For completeness, FIG. 11 is a schematic diagram of components of one or more of the example embodiments described previously, which hereafter are referred to generically as a processing system 300. The processing system 300 may, for example, be the apparatus referred to in the claims below. The processing system 300 may have a processor 302, a memoiy 304 closely coupled to the processor and comprised of a RAM 314 and a ROM 312, and, optionally, a user input 310 and a display 318. The processing system 300 may comprise one or more network / apparatus interfaces 308 for connection to a network / apparatus, e.g. a modem which may be wired or wireless. The network / apparatus interface 308 may also operate as a connection to other apparatus such as device / apparatus which is not network side apparatus. Thus, direct connection between devices / apparatus without network participation is possible.

[0103] The processor 302 is connected to each of the other components in order to control operation thereof.

[0104] The memory 304 may comprise a non-volatile memory, such as a hard disk drive (HDD) or a solid state drive (SSD). The ROM 312 of the memory 304 stores, amongst other things, an operating system 315 and may store software applications 316. The RAM 314 of the memory 304 is used by the processor 302 for the temporary storage of data. The operating system 315 may contain code which, when executed by the processor implements aspects of the algorithms and sequences 60, 70. 80, 90 and too described above. Note that in the case of small device / apparatus the memory can be most suitable for small size usage i.e. not always a hard disk drive (HDD) or a solid state drive (SSD) is used.

[0105] The processor 302 may take any suitable form. For instance, it may be a microcontroller, a plurality of microcontrollers, a processor, or a plurality of processors.

[0106] The processing system 300 maybe a standalone computer, a server, a console, or a network thereof. The processing system 300 and needed structural parts may be all inside device / apparatus such as loT device / apparatus i.e. embedded to very small size. In some example embodiments, the processing system 300 may also be associated with external software applications. These may be applications stored on a remote server device / apparatus and may run partly or exclusively on the remote server device / apparatus. These applications maybe termed cloud-hosted applications. The processing system 300 may be in communication with the remote server device / apparatus in order to utilize the software application stored there.

[0107] FIG. 12 shows a tangible media, in the form of a removable memory unit 365, storing computer-readable code which when run by a computer may perform methods according to example embodiments described above. The removable memory unit 365 may be a memory stick, e.g. a USB memory stick, having internal memory 366 storing the computer-readable code. The internal memory 366 may be accessed by a computer system via a connector 367. Of course, other forms of tangible storage media may be used, as will be readily apparent to those of ordinary skilled in the art. Tangible media can be any device / apparatus capable of storing data / information which data / information can be exchanged between devices / apparatus / network.

[0108] Embodiments of the present invention may be implemented in software, hardware, application logic or a combination of software, hardware and application logic. The software, application logic and / or hardware may reside on memory, or any computer media. In an example embodiment, the application logic, software or an instruction set is maintained on any one of various conventional computer-readable media. In the context of this document, a “memory” or “computer-readable medium” may be any non-transitory media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer.

[0109] Reference to, where relevant, “computer-readable medium”, “computer program product”, “tangibly embodied computer program” etc., or a “processor” or “processing circuitry” etc. should be understood to encompass not only computers having differing architectures such as single / multi-processor architectures and sequencers / parallel architectures, but also specialised circuits such as field programmable gate arrays

[0110] FPGA, application specify circuits ASIC, signal processing devices / apparatus and other devices / apparatus. References to computer program, instructions, code etc. should be understood to express software for a programmable processor firmware such as the programmable content of a hardware device / apparatus as instructions for a processor or configured or configuration settings for a fixed function device / apparatus, gate array, programmable logic device / apparatus, etc.

[0111] If desired, the different functions discussed herein may be performed in a different order and / or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined. Similarly, it will also be appreciated that the flow diagrams and sequences of Figures 6 to 10 are examples only and that various operations depicted therein may be omitted, reordered and / or combined. It will be appreciated that the above described example embodiments are purely illustrative and are not limiting on the scope of the invention. Other variations and modifications will be apparent to persons skilled in the art upon reading the present specification.

[0112] Moreover, the disclosure of the present application should be understood to include any novel features or any novel combination of features either explicitly or implicitly disclosed herein or any generalization thereof and during the prosecution of the present application or of any application derived therefrom, new claims may be formulated to cover any such features and / or combination of such features. Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described example embodiments and / or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims. It is also noted herein that while the above describes various examples, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims.

Claims

Claims1. An apparatus comprising: means for receiving configuration information relating to a device of a wireless communication system, said configuration information including channel state information acquisition capabilities of the device and channel state information processing modes of operation supported by the device; means for determining activation and distribution of one or more channel state information error processing modules based, at least in part, on the received configuration information and setting a channel state information processing mode of operation accordingly; means for providing a mode of operation message, said mode of operation message defining a channel state information processing mode of operation for use by the device; and means for receiving channel state information from the device in accordance with the defined mode of operation.

2. An apparatus as claimed in claim 1, wherein the channel state information processing mode of operation includes at least one of: a first or energy efficient mode; a second or moderate energy mode; and a third or high energy mode.

3. An apparatus as claimed in claim 1 or claim 2, wherein the channel state information error processing modules comprise at least one of: an error detection module that identifies errors in a codeword received from the device over said channel; a first error correction module that corrects errors detected in the codeword received from the device over said channel; and a second error correction module that corrects for errors in a codeword generated at the device resulting from errors in channel estimation.

4. An apparatus as claimed in any one of claims 1 to 3, further comprising: means for receiving a suggested channel state information processing mode of operation from the device, wherein said mode of operation message includes an indication of whether or not the suggested mode of operation is accepted.

5. An apparatus as claimed in any one of the preceding claims, further comprising: means for rescheduling transmission of channel state information from the device in the event that an error is said channel state information is identified.

6. An apparatus as claimed in any one of the preceding claims, further comprising: means for correcting the received channel state information in the event that an error is said channels state information is identified. . An apparatus as claimed in any one of the preceding claims, wherein the apparatus is a network node of the wireless communication system.

8. A device comprising: means for providing, to a network node of a wireless communication system, configuration information relating to the device, wherein said configuration information includes channel state information acquisition capabilities of the device and channel state information processing modes of operation supported by the device; means for receiving a mode of operation message from the network node; means for generating channel state information in accordance with a channel state information processing mode of operation defined by the mode of operation message; and means for providing the generated channel state information to the network node.

9. A device as claimed in claim 8, further comprising: means for providing a suggested channel state information processing mode of operation to the network node, wherein said mode of operation message includes an indication of whether or not the suggested mode of operation is accepted.

10. A device as claimed in claim 8 or claim 9, wherein the channel state information processing mode of operation includes at least one of: a first or energy efficient mode; a second or moderate energy mode; and a third or high energy mode.

11. A device as claimed in any one of claims 8 to 10, further comprising:means for activating and distributing one or more channel state information error processing modules based, at least in part, on said mode of operation message.

12. A device as claimed in any one of claims 8 to 11, wherein the device is a user device of the mobile communication system.

13. A method comprising: receiving configuration information relating to a device of a wireless communication system, said configuration information including channel state information acquisition capabilities of the device and channel state information processing modes of operation supported by the device; determining activation and distribution of one or more channel state information error processing modules based, at least in part, on the received configuration information and setting a channel state information processing mode of operation accordingly; providing a mode of operation message, said mode of operation message defining a channel state information processing mode of operation for use by the device; and receiving channel state information from the device in accordance with the defined mode of operation.

14. A method comprising: providing, to a network node of a wireless communication system, configuration information relating to a device, wherein said configuration information includes channel state information acquisition capabilities of the device and channel state information processing modes of operation supported by the device; receiving a mode of operation message from the network node; generating channel state information in accordance with a channel state information processing mode of operation defined by the mode of operation message; and providing the generated channel state information to the network node.

15. A computer program comprising instructions which, when executed by an apparatus, cause the apparatus to:receive configuration information relating to a device of the wireless communication system, said configuration information including channel state information acquisition capabilities of the device and channel state information processing modes of operation supported by the device; determine activation and distribution of channel state information error processing modules based, at least in part, on the received configuration information and setting a channel state information processing mode of operation accordingly; provide a mode of operation message, said mode of operation message defining a channel state information processing mode of operation for use by the device; and receive channel state information from the device in accordance with the defined mode of operation.

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