Rate-splitting multiple access and automatic repeat request

Abstract

A wireless communication device (121) communicates with a cellular network (119) using a rate-splitting multiple access, RSMA, transmission (140). The RSMA transmission is protected by an automatic repeat request, ARQ, scheme (180). A common part (230) of RSMA messages encodes ARQ information (4200).

Description

[0001] D E S C R I P T I O N

[0002] RATE-SPLITTING MULTIPLE ACCESS AND AUTOMATIC REPEAT REQUEST

[0003] TECHNICAL FIELD

[0004] Various examples generally relate to protocols for wirelessly transmitting in a communication system. Various examples of the disclosure specifically relate to a multipleaccess transmission in combination with automatic repeat request scheme.

[0005] BACKGROUND

[0006] The Third Generation Partnership Project (3GPP) provides standardization of communication between wireless communication devices (also referred to as user equipment, UE) and a cellular network. There are multiple standards available or in development, including the upcoming 6G standard.

[0007] A particular technique is multiple access (MA). MA allows multiple UEs to transmit or receive information simultaneously over a shared communication channel. This ensures efficient use of available bandwidth by managing the allocation of the channel among various users without interference.

[0008] A special form of MA is rate-splitting multiple access (RSMA)which uses RSMA messages including two parts: a common part, decodable by every user, and a private part, decodable only by the intended user. Each user first decodes the common message and then decodes its private message by applying successive interference cancellation (SIC). This increases performance by mitigating inter-user interference in a broad range of interference regimes.

[0009] SUMMARY

[0010] There is a need for advanced RSMA techniques. In particular, there is a need for increasing performance in RSMA transmissions.

[0011] This need is met by the features of the independent claims. The features of the dependent claims define embodiments.

[0012] Hereinafter, techniques of wirelessly communicating between a base station of a cellular network and multiple UEs are disclosed.

[0013] A method for use in a wireless communication device is disclosed. The wireless communication device communicates with a cellular network using a rate-splitting multiple access, RSMA, transmission. The RSMA transmission is protected by an automatic repeat request, ARQ, scheme. The method includes receiving a first RSMA message comprising a first common part, a first private part associated with the wireless communication device and one or more further first private parts associated with one or more further wireless communication devices. The first common part encodes a portion associated with the wireless communication device and further encodes one or more further portions associated with the one or more further wireless communication devices. The method further includes, upon failing to decode the first common part, receiving a second RSMA message comprising a second common part, the second common part encoding ARQ information of the first common part.A respective wireless communication device comprises a control circuitry configured to perform such method.

[0014] A method for use in an access node of a cellular network is disclosed. A plurality of wireless communication devices communicate with the cellular network through the access node using a rate-splitting multiple access, RSMA, transmission protected by an automatic repeat request, ARQ, scheme. The method includes transmitting a first RSMA message to the plurality of wireless communication devices. The first RSMA message includes a first common part and multiple private parts associated with each of the plurality of wireless communication devices. The first common part encodes multiple portions associated with each of the plurality of wireless communication devices. The method also includes, upon at least one of the plurality of wireless communication devices failing to decode the first common part, transmitting a second RSMA message to the plurality of wireless communication devices. The second RSMA message includes a second common part, the second common part encoding an ARQ information for the first common part.

[0015] A respective access node comprises a control circuitry configured to perform such method.

[0016] A communication system comprises such access node and wireless communication device.

[0017] It is to be understood that the features mentioned above and those yet to be explained below may be used not only in the respective combinations indicated, but also in other combinations or in isolation without departing from the scope of the invention.

[0018] BRIEF DESCRIPTION of the DRAWINGS

[0019] FIG. 1 schematically illustrates a communication system including multiple UEs connected to a cellular network through a base station of the cellular network according to various examples.

[0020] FIG. 2A schematically illustrates a transmitter-side operation for an RSMA transmission according to various examples.

[0021] FIG. 2B schematically illustrates an RSMA message according to various examples. FIG. 3 schematically illustrates receiver-side operation for an RSMA transmission according to various examples.

[0022] FIG. 4 is a signaling diagram illustrating an Automatic Repeat Request scheme facilitating error protection through at least partial re-transmission according to various examples.

[0023] FIG. 5 is a flowchart of a method for use in the UE according to various examples.

[0024] FIG. 6 schematically illustrates a mapping of Automatic Repeat Request information to an RSMA message according to various examples.

[0025] FIG. 7 schematically illustrates decoding failures concurrently reoccurring for a given common part of an RSMA message or multiple UEs according to various examples.

[0026] FIG. 8 schematically illustrates receiver-side operation for an RSMA transmission according to various examples.

[0027] FIG. 9 is a flowchart of a method for use in a BS according to various examples.

[0028] FIG. 10 is a signaling diagram according to various examples.FIG. 11 is a signaling diagram according to various examples.

[0029] FIG. 12 is a signaling diagram according to various examples.

[0030] FIG. 13 schematically illustrates a BS according to various examples.

[0031] FIG. 14 schematically illustrates a UE according to various examples.

[0032] DETAILED DESCRIPTION

[0033] Some examples of the present disclosure generally provide for a plurality of circuits or other electrical devices. All references to the circuits and other electrical devices and the functionality provided by each are not intended to be limited to encompassing only what is illustrated and described herein. While particular labels may be assigned to the various circuits or other electrical devices disclosed, such labels are not intended to limit the scope of operation for the circuits and the other electrical devices. Such circuits and other electrical devices may be combined with each other and / or separated in any manner based on the particular type of electrical implementation that is desired. It is recognized that any circuit or other electrical device disclosed herein may include any number of microcontrollers, a graphics processor unit (GPU), a tensor processing unit (TPU), integrated circuits such as application-specific integrated circuits or field-programmable gate array (FPGA) circuitrs, memory devices (e.g., FLASH, random access memory (RAM), read only memory (ROM), electrically programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), or other suitable variants thereof), and software which co-act with one another to perform operation(s) disclosed herein. In addition, any one or more of the electrical devices may be configured to execute a program code that is embodied in a non-transitory computer readable medium programmed to perform any number of the functions as disclosed.

[0034] In the following, embodiments of the invention will be described in detail with reference to the accompanying drawings. It is to be understood that the following description of embodiments is not to be taken in a limiting sense. The scope of the invention is not intended to be limited by the embodiments described hereinafter or by the drawings, which are taken to be illustrative only.

[0035] The drawings are to be regarded as being schematic representations and elements illustrated in the drawings are not necessarily shown to scale. Rather, the various elements are represented such that their function and general purpose become apparent to a person skilled in the art. Any connection or coupling between functional blocks, devices, components, or other physical or functional units shown in the drawings or described herein may also be implemented by an indirect connection or coupling. A coupling between components may also be established over a wireless connection. Functional blocks may be implemented in hardware, firmware, software, or a combination thereof.

[0036] Hereinafter, techniques are disclosed for wirelessly communicating between multiple devices of a wireless communication system. Specifically, techniques are disclosed that facilitate an MA transmission from a transmitter device to multiple receiver devices. The techniques are disclosed in a cellular framework, i.e. , the multiple receiver devices are UEs connected to a cellular network and the MA transmission is a downlink MA transmission from a BS of the cellular network to the multiple UEs. However, similar techniques may also be employed for other types of wireless communication systems.Various disclosed techniques combine an MA transmission with an Automatic Repeat Request (ARQ) scheme for protecting the MA transmission against transmission errors by facilitating on-demand retransmission. According to the ARQ scheme, ARQ information is provided to the receiver device that facilitates a further decoding attempt of data for which decoding has previously failed is transmitted upon detection of a decoding error.

[0037] Specifically, various techniques are based on the finding that encapsulating the ARQ information in the common part of an RSMA message can facilitate higher data throughput and efficiency.

[0038] More specifically, various techniques are based on the finding that upon multiple UEs participating in the RSMA transmission each encountering a decoding error for a given common part of a given RSMA message, by splitting the ARQ information into multiple fractions and spreading these multiple fractions across multiple partitions of the common part conventionally associated with these different UEs, a higher data throughput and efficiency can be obtained.

[0039] FIG. 1 schematically illustrates a communication system 100. The communication system 100 includes a BS 120 of a cellular network 119. For instance, the cellular network 119 may operate according to the 3GPP 6G protocol. The BS 120 may communicate with each of multiple UEs 121 , 122, 123 via an RSMA transmission 140, e.g., specified by the 3GPP 6G protocol. Specifically, the RSMA transmission 140 is a downlink RSMA transmission 140 from the BS 120 to the UEs 121, 122, 123.

[0040] Also illustrated in FIG. 1 is a further UE 124. The further UE 124 does not participate in the RSMA transmission 140; however, the further UE 124 communicates with the BS 120 via a separate single-access transmission 141. For instance, certain time-frequency resource blocks of a Physical Downlink Shared Channel (PDSCH) may be allocated to RSMA messages of the RSMA transmission 140 and other, orthogonal resources on the PDSCH may be allocated to messages of the single-access transmission 141.

[0041] FIG. 2A schematically illustrates aspects with respect to the downlink RSMA transmission 140. While the RSMA transmission 140 is illustrated to be from the BS 120 to the three UEs 121, 122, 123, as a general rule, more or fewer UEs may participate in RSMA transmissions in accordance with the present disclosure.

[0042] User messages 211, 221, 231 (labeled xltx2, and x3) are to be transmitted to the three UEs 121, 122, 123, respectively, by the BS 120. The user message 211 includes payload data for the UE 121 ; while the user message 221 includes payload data for the UE 122 and the user message 231 includes payload data for the UE 123.

[0043] Each user message 211 , 221 , 231 x{

[0044]

[0045] = 1,2,3) is partitioned into a private part 212, 222, 232 xpand a common portion 213, 223, 233 xC){. The common portions are combined into a single, larger, common part 230 xc. These are the constituents of the RSMA message 240: the common part 230 and the private parts 212, 222, 232. Thus, the common part 230 includes multiple portions 213, 223, 233 associated - e.g., in accordance with a predefined mapping of a configuration of the RSMA transmission - with the multiple UEs participating in the RSMA transmission. Each private part 212, 222, 232 is then encoded using a private codebook, known to the corresponding user only. The common part 230 including the user-specific portions 213, 223, 233 is jointly encoded using a codebook known to all users. Error correction encodingof the four constituents 212, 222, 232, 230 %p,i> %p,2,p,3>c'sperformed. The BS 120 selects multi-antenna precoders (amplitude and phase of each antenna element) for four spatial streams (exploiting spatial diversity), illustrated by the antenna ports 251, 252, 253, 254. Thus, as will be appreciated, a feature of RSMA is to split individual users’ messages 211, 221, 231 into a common portion and a private part, thereafter to construct a common RSMA message by jointly encoding the common portions (common part 230 of the RSMA message 240) and separately encoding each of the private parts.

[0046] As a general rule, according to the RSMA transmission 140, a relative size of the common part 230 relative to a size of the private parts 212, 222, 232 is adjustable. For instance, in an extreme scenario, a size of the private parts 212, 222, 232 may be much smaller than a size of the common part 230. This scenario may be compared to Non-Orthogonal MA (NOMA). In NOMA, a certain user may fully decode other users’ messages, also referred to as joint decoding. If, on the other hand, the size of the common part 230 tends to be negligible of compared to the sizes of the private parts 212, 222, 232, the RSMA corresponds to a Spatial Division (SDMA) multiple-input Multiple-output (MIMO) transmission in which each UE is served via a separate spatial stream, addressed by the respective precoders of the respective antenna port. As will be appreciated, RSMA may be seen as a combination of NOMA (for the common part 230) and SDMA (for the private parts 212, 222, 232). Thus, benefits of the RSMA transmission include efficiency and robustness and flexibility in various scenarios such as varying number of UEs and varying channel conditions.

[0047] FIG. 2B illustrates the resulting RSMA message 299.

[0048] Next, operation at the receiver side of the downlink RSMA transmission 140 - e.g., at the UE 121 - will be discussed.

[0049] FIG. 3 schematically illustrates receiver-side operation of a receiver of the RSMA transmission. FIG. 3 schematically illustrates operation of the UE 121. However, techniques illustrated in FIG. 3 are equally applicable to, e.g., the UE 122 and the UE 123. Briefly, a receiving device of data in RSMA transmission employs SIC: Initially, each UE decodes the common part 230 and then removes an associated signal waveform from the received signal waveform.

[0050] In detail, the UE 121 picks up the received signal y* at box 6005; and, at box 6010 decodes the common part 230 xcfrom the received signal yiby treating other signal components (associated with other spatial streams) including the private part 212

[0051]

[0052] las interference / noise.

[0053] At box 6010, it may be determined whether a decoding error is present. A cyclic redundancy checksum (CRC) may be used to verify whether or not the sequence of bits obtained from the decoding process has been decoded correctly. The CRC, at the transmitter side, is added before error correction encoding. After decoding of the error correcting code, one checks if the CRC is valid for the decoded bits or not.

[0054] If a decoding error is detected at box 6010, the UE buffers (box 6011) certain information obtained from box 6005 and / or from box 6010 of box 6005 in internal buffer and requests ARQ information for a subsequent decoding attempt; respective details with respect to an ARQ scheme will be explained later on.For example, the UE may buffer the received signal and / or log-likelihood ratios (LLRs) of encoded bits or similar indicators of the encoded bits obtained from the decoding attempt of box 6010. The first step of a receiver is to perform demodulation of the received signal according to the constellation. The result of this is one LLR per codebit. This is typically more efficient to store (and also sufficient) than the recieved signal itself.

[0055] If no decoding error is detected at box 6010, the UE 121 then extracts (6015) the particular portion 213 %C 1directed to the UE 121 from the common part 230, xc; and disregards the other portions 223, 233 xC;2and xC;3(6016). These other portions 223, 233 of the common part 230 include payload data directed to the other UEs 122, 123; and, as such, are to be discarded by the UE 121.

[0056] At box 6020, the UE 121 cancels the signal component due to the common part xcfrom the received signal of box 6005.

[0057] At box 6025, the UE 121 decodes the private part 212 xpfrom the interference-cancelled received signal (obtained from box 6020) by treating signal components associated with other data streams (i.e., xP; 2,xp 3) as noise / interference.

[0058] As will be appreciated from the above, the receiver-side operation illustrated in FIG. 3 includes decoding, at box 6010, using a coding codebook known to all users of UEs 121, 122, 123; as well as decoding at box 6025 using a decoding codebook only known to the user associated with the UE 121.

[0059] At box 6030, the user-specific message 211 is reconstructed, by combining the respective user-specific portion 213 of the common part 230 with the private part 212 xP;1. This user-specific message 211 can then be passed onto a higher layers of the Open Systems Interconnection (OSI) transmission protocol stack for further processing.

[0060] The OSI transmission protocol stack is a conceptual framework that defines a structured set of protocols for network communication, organized into seven distinct layers. Each layer serves a specific function and interfaces only with the layers directly above and below it, thereby simplifying the complexities of network interactions and ensuring interoperability among heterogeneous systems. The stack begins with the Physical Layer (Layer 1), which manages the physical transmission of raw bit streams over a communication medium, including tasks such as signal transmission and reception, and modulation and demodulation processes. The Data Link Layer (Layer 2) above it ensures reliable transmission of data across the physical network by handling error detection and correction, frame synchronization, and flow control. The model progresses up to the Application Layer (Layer 7), which provides protocols for software applications to communicate over a network, completing the architecture that facilitates a wide range of network services and applications. Next, it is explained which layers are involved in the processes illustrated in FIG. 3.

[0061] Physical Layer (Layer 1): This layer is involved when the UE 121 picks up the received signal waveform y±. The physical layer handles the transmission and reception of raw bit streams over a physical medium, which includes the modulation and demodulation of signals on the carrier frequency. Data Link Layer (Layer 2): The processes that involve decoding the common message and the private parts, as well as error detection (decoding checksum), fall under the data link layer. This layer ensures that data frames are error-free by employing errordetection and correction techniques. It is also responsible for the MAC (Media Access Control) sublayer tasks, which manage protocol access to the physical network medium.

[0062] Hereinafter, techniques are disclosed that enable mitigating failed decoding at box 6010, i.e., failed decoding of the common part of the RSMA message. Decoding may be detected based on error-coding checksums such as cyclic redundancy checks (CRCs). Upon detection of a decoding failure, ARQ information may be requested in accordance with an ARQ scheme. An ARQ scheme is shown in Fig. 4.

[0063] FIG. 4 schematically illustrates aspects with respect to an ARQ scheme 180. FIG. 4 schematically illustrates the ARQ scheme 180 with respect to downlink communication from the BS 120 to the UE 121; similar ARQ schemes may be implemented with respect to downlink communication from the BS 120 to each of the remaining UEs 122, 123.

[0064] The ARQ scheme 180 may operate on Layer 2 of the OSI transmission protocol stack. As such, when a message 4005 is transmitted, this can be a message including data encoded on Layer 2. The message 4005 may be, e.g., the common part 230 of the RSMA transmission 140 (cf. FIG. 2A). Likewise, the message 4005 may be the private part 212 of the RSMA transmission 140 (however, error protection of the private parts of the RSMA transmission 140 is out of scope of the subject disclosure).

[0065] At 5005, a scheduling message 4004 is transmitted by the BS 120. For instance, this may be Downlink Control Information (DCI) transmitted on a Physical Downlink Control Channel (PDCCH). The scheduling message 4004 allocates resources in time and frequency domain for the subsequently transmitted message 4005. The message 4005 is transmitted at 5010.

[0066] Upon a decoding failure, the UE 121 sends a negative acknowledgment to the BS 120, at 5015. It is not required in all scenarios that a negative acknowledgment 4010 is transmitted; alternatively, the BS 120 may check whether a positive acknowledgment is received within a predefined time duration.

[0067] Then, ARQ information 4020 is transmitted at 5025; on the time-frequency resources indicated by a respective scheduling message 4004 transmitted by the BS 120 at 5020. The scheduling information 4004 includes an indicator that is indicative of the message transmitted next at 5025 being or including ARQ information.

[0068] The ARQ information 4020 may be a redundancy version of the initial message 4005 or may be incremental redundancy information for the initial message 4005. The term "redundancy version" may refer to a duplicate or replicate copy of an original message. In the context of error control coding and correction, a redundancy version of a message can be generated by adding redundant information to the original message, such that if errors occur during transmission, the original message can still be recovered from the received data. This is often achieved through techniques such as checksums Forward Error Correct (FEC) check bits or other forms of forward error correction. By transmitting a redundancy version of a message, the receiver can detect and correct errors that may have occurred during transmission. On the other hand, "incremental redundancy information" refers to additional redundant data that is transmitted in addition to an original message, but which does not duplicate the entire message. Instead, incremental redundancy information provides supplementary error correction capabilities. For incremental redundancy information, decoding at the receiver typically involves combining theoriginal message with the additional redundant data. On the other hand, for a complete redundancy version of the initial message, the receiver may discard the initial message after decoding has failed and re-attempt decoding of the encoded data based on the redundancy version of the message only; alternatively, also a combination of the initial message may be helpful to obtain better decoding results. Typically, the amount of information bits required for providing a complete redundancy version is significantly larger if the amount of information bits required for incremental redundancy information. Furthermore, by adjusting a redundancy factor of the incremental redundancy information, a number of information bits, i.e., a size of the incremental redundancy information can be flexibly adjusted.

[0069] In addition to transmitting redundancy versions or incremental redundancy information, an ARQ scheme may also employ hybrid ARQ techniques. Hybrid ARQ (HARQ) refers to a combination of different error control strategies, such as forward error correction (FEC) and ARQ, to provide reliable data transmission. In a hybrid ARQ scheme, the BS 120 may initially transmit a message with a moderate level of FEC coding, which provides some degree of error protection. If errors occur during transmission, the UE 121 may detect these errors using techniques such as cyclic redundancy checks (CRCs) or checksums. Upon detecting errors, the UE 121 may request retransmission of the message, and the BS 120 may respond by transmitting additional incremental redundancy information to aid in error correction; again FEC information may be included.

[0070] FIG. 5 is a flowchart of a method according to various examples. The flowchart of FIG. 5 is for use in a UE such as the UEs 121, 122, 123 (cf. FIG. 1). The UE communicates with a cellular network using an RSMA transmission. In particular, the UE receives data via a downlink RSMA transmission. The UE is connected to the cellular network via a respective serving BS, such as the BS 120 (cf. FIG. 1).

[0071] The method of FIG. 5 may be executed by a processing circuitry of the UE. For instance, at least parts of the method of FIG. 5 may be executed by a processor upon loading program code from a memory and upon executing the program code. Some parts of the method of FIG.

[0072] 5 may also be implemented by a radio-frequency front end of the UE.

[0073] Hereinafter, for sake of simplicity, it will be assumed that the method of FIG. 5 is executed by the UE 121 that communicates with the cellular network 119 via the BS 120. In particular, the UE 121 participates in the downlink RSMA transmission 140, as previously explained in connection with FIG. 1.

[0074] At box 3005, at timepoint t, the UE 121 receives a first RSMA message. The first RSMA message includes a first common part (cf. FIG. 2A: common part 230) as well as a first private part associated with the UE (cf. FIG. 2A: private part 212) as well as one or more further first private parts associated with one or more further UEs (cf. FIG. 2A: private part 222, 232). The first common part encodes a portion associated with the UE 121 (cf. FIG. 1: portion 213) executing the method of FIG. 5 as well as one or more further portions (cf. FIG. 1: portions 223, 233) associated with one or more further wireless communication devices.

[0075] Aspects with respect to the receiver-side operation have been previously discussed in connection with FIG. 3. In particular, decoding of the common part of decoding of the privatepart have been previously discussed. Box 3005 can include one or more boxes as discussed in FIG. 3.

[0076] Upon a decoding failure (box 3010), at timepoint t', the UE receives a second RSMA message at box 3020. The second RSMA message comprises a respective second common part that encodes ARQ information of the first common part of the first RSMA message received at box 3005. Thus, as will be appreciated, the ARQ information is encapsulated in the common part of an RSMA message.

[0077] Box 3010 may include the UE checking a CRC. Box 3010 may include the UE checking in error checksums for consistency.

[0078] Prior to receiving the second RSMA message at box 3020, the UE may optionally obtain an indication (box 3015) that the subsequent second RSMA message carries the ARQ information.

[0079] The second RSMA message includes a common part (cf. FIG. 2A: common part 230) as well as a second private part associated with the UE (cf. FIG. 2A: private part 212) as well as one or more further second private parts associated with one or more further UEs (cf. FIG. 2A: private part 222, 232). The second common part encodes a portion associated with the UE 121 (cf. FIG. 1: portion 213) executing the method of FIG. 5 as well as one or more further portions (cf. FIG. 1: portions 223, 233) associated with one or more further wireless communication devices.

[0080] The first and second RSMA messages are similarly structured, e.g., in accordance with a configuration of the RSMA transmission.

[0081] The second RSMA message carries the ARQ information (of the common part of the first RSMA message) in its common part.

[0082] As a general rule, various options are conceivable for including the ARQ information in the portions of the common part that are associated with the UEs participating in the RSMA transmission.

[0083] In a first example, the ARQ information for the UE 121 may exclusively be included in the portion of the common part that is associated with that particular UE 121 ; in other words, portions of the common part associated with other UEs do not include the ARQ information used by any particular UE in accordance with the ARQ scheme. Each UE only reads its own portions of the common part. Other common parts are discarded.

[0084] In a second example, while a fraction of the ARQ information is included in the portion of the common part associated with the UE 121, a further fraction of the ARQ information may optionally be included in the private part of the second RSMA message associated with the UE 121 (cf. FIG. 2A: private part 212).

[0085] In a third example, the ARQ information is entirely included in the common part of the second RSMA message - so that the private parts of the second RSMA message do not include any ARQ information. In other words, ARQ information may be consistently carried exclusively by the common part of the RSMA message(s).

[0086] A specific example of including the ARQ information in the RSMA message is illustrated in connection with FIG. 6.FIG. 6 schematically illustrates an example of including ARQ information in an RSMA message. In the scenario of FIG. 6, the ARQ information 4200 used by a particular UE (e.g., the UE 121) is split into multiple fractions 4201, 4202 at box 6305: these fractions 4201, 4202 are then carried by multiple portions 213, 223 of the common part 230 of the respective RSMA message. The remaining portion 233 of the common part 230 may include user-specific data for the other respective UE. Thus, as will be appreciated, from the perspective of the UE 121, upon failing to decode the common part of an initial RSMA message at timepoint t, the RSMA message at timepoint t' > t includes the respective ARQ information not only in the portion 213 of the common part 230 associated with that particular UE 121. Rather, a fraction 4202 of the ARQ information 4200 is included in a portion 223 of the common part 230 associated with another UE (in the present scenario the UE 122).

[0087] This means that the UE 121 does not discard the portion 223 of the common part 230 of the RSMA message; but rather reads the portion 223 of the common part 230 in order to subsequently reconstruct the ARQ information 4200 based on its multiple fractions 4201 , 4202 distributed across these portions 213, 223 of the common part 230 of the RSMA message.

[0088] Such scenario as discussed in connection with FIG. 6 may be in particular applicable to joint decoding failure at multiple UEs, as illustrated in FIG. 7. Here, both the UE 121 as well as the UE 122 fail at decoding the common part (box 6350 at box 6355; these boxes correspond to box 3010 in FIG. 5 as well as box 6010 in FIG. 3); while the UE 123 does not fail in decoding the common part (box 6360) and, accordingly, can commence with decoding the private part at box 6370 (this box corresponds to box 6025 in FIG. 3). As will be appreciated from the above, multiple UEs - here, e.g., the UE 121 and the UE 122 - have failed jointly to decode the common part 230. Since the same codebook is used for both UEs 121, 122, similar ARQ information is required by both UEs 121, 122.

[0089] More generally, the following technique of including the ARQ information in the RSMA message is described above using a specific example: Let the ARQ information for an RSMA message xc(t)be denoted by HARQ^', this notation should be read as “ARQ information for the common part transmitted at time t”. Then, that ARQ information HARQ^ can be transmitted in the common part of a future RSMA message (at time t')> in respective portions x^ and x^2The rationale of doing so is that both UEs that earlier failed to decode the common part of the RSMA message transmitted at time t will, at time t', decode

[0090]

[0091] )and thereby obtain x^ and x^ which comprise the required ARQ information HARQ^ needed at both UEs. By splitting the HARQ information across two portions of the common part, the UEs need to disregard as little information as possible and thereby the transmission efficiency is improved. The RSMA technique is combined with a multicast distribution of the HARQ information, thereby increasing the spectral efficiency. Instead of transmitting the HARQ information required by each of multiple UEs separately to each of these multiple UEs, a multicast distribution of the HARQ information is enabled: multiple UEs each use the same information bits that carry the HARQ information jointly applicable to recovering decoding failures at these multiple UEs.

[0092] FIG. 8 schematically illustrates receiver-site operation of a receiver of the RSMA transmission. FIG. 8 schematically illustrates the operation of the UE 121. However, techniques illustrated in FIG. 8 are equally applicable to, e.g., the UE 122 and the UE 123.FIG. 8 may build upon FIG. 3: FIG. 8 describes a scenario in which the UE 121 at box 6010 has detected a decoding error. FIG. 8 pertains to operation at timepoint t' which is later than timepoint t of FIG. 3. FIG. 8, as such, may pertain to operation associated with box 3020 of the method of FIG. 5; while previously, in connection with FIG. 3, operation associated with box 3005 and box 3010 of the method of FIG. 5 have been discussed.

[0093] At box 6605, the UE 121 picks up the respective signal y and at box 6610 decodes the common part 230 from the received signal. Box 6610 thus corresponds to box 6010 as previously explained in connection with FIG. 3.

[0094] It is now assumed that a decoding error is not detected so that the UE 121 obtains the common part 230. It extracts, at 6615, the portion 213 associated with the UE 121 as well as the portion 223 generally associated (e.g., in accordance with a predefined association defined by the RSMA transmission 140) with the UE 122. These portions carry respective fractions 4201, 4202 (cf. FIG. 6) of the ARQ information that is reconstructed at box 6680. The UE 121 only needs to disregard, at 6616, the portion 233 of the common part 230. For instance, this portion 233 may carry payload data directed to the UE 123.

[0095] Based on the ARQ information 4200, the UE 121 then commences at box 6685 to decode the common part of the earlier RSMA message (cf. FIG. 3); this is based on the respective buffered received waveform obtained at box 6604; box 6604 thus reads the data that has been stored at box 6011 (cf. FIG. 3). Upon being able to decode the common part at box 6685, the method can commence at box 6020 as well as box 6015 of FIG. 3.

[0096] Also illustrated in FIG. 8 is box 6620 which corresponds to box 6020; box 6625 which corresponds to box 6025.

[0097] As will be appreciated from the above, when executing FIG. 8, the UE 121 needs to be aware that the ARQ information 4200 is to be reconstructed, at box 6680, from the portions 213, 223 of the common part 230 of the respective RSMA message. In other words, the UE 121 needs to be aware of the ARQ information 4200 not only being included in the portion 213 that is natively associated with the UE 121 ; but a fraction of the ARQ information 4200 also being included in the portion 223 of the common part 230 natively associated with another UE 122. This knowledge enables the UE 121 overriding the normal - i.e. , non-ARQ-retransmission -operation (depicted, e.g., in FIG. 3) according to which it would generally discard the portion 223; but rather read the portion 223 in order to reconstruct the ARQ information 4200, as illustrated in FIG. 8 in connection with 6615.

[0098] For instance, the UE may obtain an indicator that is indicative of these two portions 213, 233 as carrying the ARQ information for 200. The indicator may be included in a scheduling message for the signal picked-up at 6605. The indicator may be included in a DCI. For instance, respective aspects have been previously discussed in connection with the scheduling messages 4004 in FIG. 4.

[0099] FIG. 9 is a flowchart of a method according to various examples. The method of FIG. 9 is for use in a BS such as the BS 120 (cf. FIG. 1). The BS is part of a cellular network and communicates with multiple UEs such as the UEs 121, 122, 123 (cf. FIG. 1) using an RSMA transmission. In particular, the BS transmits data via a downlink RSMA transmission.The method of FIG. 9 may be executed by a processing circuitry of the BS. For instance, at least parts of the method of FIG. 9 may be executed by a processor upon loading program code from a memory and upon executing the program code. Some parts of the method of FIG.

[0100] 9 may also be implemented by a radio-frequency front end of the BS.

[0101] For sake of simplicity, hereinafter, the method of FIG. 9 will be explained in the context of BS 120. The method, however, is generally applicable to other connectivity scenarios and other BSs.

[0102] At box 3105, the BS transmits a first RSMA message. Box 3105 corresponds to box 3005 of the method of FIG. 5. This corresponds to timepoint t, as previously discussed.

[0103] At box 3110, the BS 120 judges whether a decoding failure has occurred at one or more UEs. For instance, box 3110 may include obtaining an indication that two or more of the UEs -e.g., the UE 121 as well as the UE 122, as in the scenario of FIG. 7 - have failed to decode the common part.

[0104] For instance, respective negative acknowledgments may be obtained. These negative acknowledgments may not only indicate that the respective user-specific messages (cf. FIG. 2A: UE messages 211, 221, 231) have failed decoding; rather, the negative acknowledgment may indicate that decoding of the common part of a respective RSMA message carrying the respective UE messages has failed.

[0105] Then, the BS 120, at box 3115, may optionally provide an indication to the UEs 121, 122 that the ARQ information for the common part of the initial, first RSMA message of box 3105 will be included in the partitions of the subsequently transmitted second RSMA message associated with those UEs 121, 122 that have reported decoding failure. This enables those UEs 121, 122 that have experienced a decoding failure to appropriately reconstruct the ARQ information by considering the relevant portions of the common part of the subsequent RSMA message transmitted at box 3120. Each of these portions includes different fractions of the ARQ information. Thus, box 3115 corresponds to box 3015 and box 3120 corresponds to box 3020.

[0106] As will be appreciated from the above, the more UEs jointly fail to decode the common part of the RSMA message, the more partitions of the common part can be used for accommodating the ARQ information. Thus, in other words, the more UEs jointly fail to decode the common part of the RSMA message, the larger the respective information fields that can carry the ARQ information. Accordingly, the BS 120 may configure the size of the ARQ information based on the count of the multiple UEs that have failed to decode the common part of the preceding RSMA message, at box 3115 before providing a respective indication. A redundancy factor of incremental redundancy information may be adjusted to tailor the size of the ARQ information. Such redundancy factor may also be signaled to the UEs so that they can appropriately adjust a decoding process. For instance, such redundancy factor or other decoding-related information may be included in the indication provided at box 3115 for the UEs.

[0107] A redundancy factor of incremental redundancy information refers to a parameter that controls the amount of redundant data added to an original message for error correction purposes. The redundancy factor is typically a value that indicates how much redundant data is added to an original message relative to its original size. For example, a redundancy factor of1 / 2 may indicate that half as many bits are added as redundant data compared to the original message size.

[0108] FIG. 10 is a signaling diagram of communication between the BS 120 and the UE 121, the UE 122, the UE 123, as well as the UE 124 (cf. FIG. 1). FIG. 10 illustrates aspects with respect to configuration and execution of the RSMA transmission 140.

[0109] Initially, each of the UEs 121, 122, 123, 124 provides a respective capability message 4205 to the BS 120 (5205, 5210, 5215, 5220).

[0110] The capability message 4205 indicates whether the particular UE supports or does not support including theARQ information in the common part of the RSMA message. The capability message 4205 may specifically indicate whether the particular UE supports or does not support fractioning of the ARQ information across multiple portions of the common part of an RSMA message. For instance, in the scenario FIG. 10, this is supported by each of the UEs 121, 122, 123; but not supported by the UE 124. Accordingly, the BS 120 groups the UEs 121, 122, 123 to participate in the RSMA transmission 140; while the UE 124 is served via a single access transmission.

[0111] More generally, the BS 120 may group multiple UEs into an RSMA transmission group depending on their capability to support fractionating of theARQ information across multiple portions of the common part of RSMA messages.

[0112] The BS 120 provides a configuration message 4210 to each of the UEs 121, 122, 123 (5225, 5230, 5235). The configuration message 4210 includes a configuration of the RSMA transmission. The configuration of the RSMA transmission 140 may include such properties as a size ratio between the common part and the private parts of each RSMA message. The configuration of the RSMA transmission 140 also includes an indication indicative of a scheme for communicating theARQ information. For instance, this scheme may indicate how the RFQ information is fractioned and distributed across multiple partitions of the common part.

[0113] While in the scenario of FIG. 10, the configuration of the RSMA transmission is determined by the BS 120 and then provided to each of the participating UEs 121 , 122, 123 which obtain that configuration from the BS 120, in other scenarios, the configuration may be predefined or may be determined at one or more of the UEs 121 , 122, 123.

[0114] Then, the BS 120 schedules a first RSMA message 4250 using respective DCI 4240 (an example of a scheduling message) transmitted, at 5240, 5245, 5250, to each of the UEs 121, 122, 123.

[0115] The RSMA message 4250 is then transmitted at 5255. Decoding of the common part fails at the UE 121 and the UE 122 (similar to what has been previously exemplified in connection with FIG. 7). Accordingly, these UEs 121, 122 provide a respective negative acknowledgment 4255 at 5260, 5265 to the BS 120.

[0116] The BS 120 then, at 5270, 5275, 5280, provides DCI 4240 for a subsequent, second RSMA message 4251. The DCI 4240 transmitted to the UE 121 and the UE 122 each comprises an indicator 5284 indicative of the respective partitions of the common part of the second RSMA message 4251 associated with the UE 121 and the UE 122 carrying respective fractions of the ARQ information for the common part of the first RSMA message 4250; while the partition of the common part of the second RSMA message 4251 associated with the UE123 carries proprietary data for that user (this is symbolized with the filled / open circles, respectively in the indicator 4252 in FIG. 10).

[0117] Then, the second RSMA message 4251 is transmitted at 5285.

[0118] The second RSMA message 4251 includes the ARQ information that is used by the UE 121 as well as by the UE 122 for decoding the common part 230 of the first RSMA message 4250.

[0119] In connection with FIG. 10 the following is noted: as illustrated, single-access transmissions are used for communicating the capability message 4205, the configuration message 4210, and the scheduling message 4240. The particular delivery mode of such messages is out-of-scope of the subject disclosure. It would be possible that also a multicast transmission is used for delivering the scheduling message 4240, for example. Furthermore, the number of UEs of participating in an RSMA transmission that jointly failing decoding the common part has been illustrated to be two in the scenario FIG. 10 as well as in other scenarios previously. However, this is for illustrative purposes only and the number of UEs that jointly or even individually fail in decoding the common part of an RSMA message may vary. This is illustrated next.

[0120] FIG. 11 is a variant of FIG. 10. The signaling of FIG. 11 corresponds to the signaling of FIG. 10; however, in contrast to the scenario of FIG. 10, at 5266, also the UE 123 indicates that it failed and decoding the common part of the RSMA message 4250. Accordingly, all partitions of the common part of the second RSMA message 4251 transmitted at 5285 carry a respective fraction of the ARQ information. This is also reflected by the indicator 5284 in FIG. 11 that differs from the respective indicator 5284 of the signaling in FIG. 10. The indicator 5284 in FIG. 11 indicates that all portions 213, 223, 233 of the common part 230 carry respective fractions of the ARQ information. FIG. 12 is yet another variant of FIG. 10 and FIG. 11. In the variant of FIG. 12, only the UE 121 fails in decoding the common part of the RSMA message 4250 that is transmitted at 5255. Accordingly, the DCI 4240 transmitted, at 5270, to that UE 121 includes a respective indicator 5299 that is indicative of the ARQ information being included only in the partition of the common part associated with the UE 121 of the RSMA message 4251 or even in the private part of the RSMA message 4251.

[0121] FIG. 13 schematically illustrates details with respect to the BS 120. The BS 120 includes a processor 911 and a memory 912. The BS 120 also includes an RF front-end 913d coupled to an array of antennas. The processor 911 can load program code from the memory 912 and execute the program code. The processor 911, upon executing the program code, can control the RF interface 913 to transmit and / or receive. The RF interface 913 can set antenna weights for selecting certain spatial streams. For instance, the processor 911 based on the program code and in combination with the RF interface 913 can execute the method according to FIG. 9.

[0122] FIG. 14 schematically illustrates details with respect to the UE 121. The remaining UEs 122-124 can be configured similarly. The UE 121 includes a processor 951 and a memory 952. The UE 121 also includes an RF front-end 953 coupled to a single antenna. Also, multi-antenna UEs would be possible. The processor 951 can load program code from the memory 952 and execute the program code. The processor 951, upon executing the program code, can control the RF interface 953 to transmit and / or receive. The processor 951, based on program codeloaded and executed, and in combination with the RF interface 953 can execute the method according to FIG. 3.

[0123] Summarizing, at least the following EXAMPLES have been disclosed:

[0124] EXAMPLE 1. A method for use in a wireless communication device (121) communicating with a cellular network (119) using a rate-splitting multiple access, RSMA, transmission (140) protected by an automatic repeat request, ARQ, scheme (180), the method comprising:

[0125] - receiving (3005) a first RSMA message (299, 4250) comprising a first common part (230), a first private part (212) associated with the wireless communication device (121) and one or more further first private parts (222, 232) associated with one or more further wireless communication devices (122, 123), the first common part (230) encoding a portion (213) associated with the wireless communication device (121) and further encoding one or more further portions (223, 233) associated with the one or more further wireless communication devices (122, 123), and

[0126] - upon failing to decode the first common part, receiving (3020) a second RSMA message (299, 4251) comprising a second common part (230), the second common part (230) encoding ARQ information (4200) of the first common part (230).

[0127] EXAMPLE 2. The method of EXAMPLE 1,

[0128] wherein the RSMA transmission (140) is based on predefined associations of the portions (213, 223, 233) of the common parts (230) of the RSMA messages to a plurality of wireless communication devices (121, 122, 123),

[0129] wherein the portion (213) of the second common part (230) associated with the wireless communication device (121) carries a fraction (4201) of the ARQ information (4200), wherein at least one portion (223) of the second common part (230) associated with at least one of the one or more further wireless communication devices (122) carries another fraction (4202) of the ARQ information (4200).

[0130] EXAMPLE 3. The method of EXAMPLE 2, further comprising:

[0131] - upon failing to decode the first common part, obtaining (3015) an indicator indicative of the at least one portion (223) of the second common part (230) associated with the at least one (122) of the one or more further wireless communication devices (122, 123) carrying the another fraction (4202) of the ARQ information (4200).

[0132] EXAMPLE 4. The method of EXAMPLE 3,

[0133] wherein the indicator is included in a scheduling message (4004) that schedules resources for the second RSMA message.

[0134] EXAMPLE 5. The method of any one of EXAMPLES 2 to 4,

[0135] wherein at least one further portion (233) of the second common part (230) associated with at least one further (123) of the one or more wireless communication devices (121 , 122, 123) carries payload data for the at least one further (123) of the one or more wireless communication devices (121, 122, 123).

[0136] EXAMPLE 6. A method for use in an access node (120) of a cellular network (119), a plurality of wireless communication devices (121, 122, 123) communicating with the cellular network (119) through the access node (120) using a rate-splitting multiple access, RSMA,transmission (140) protected by an automatic repeat request, ARQ, scheme (180), the method comprising:

[0137] - transmitting (3105) a first RSMA message to the plurality of wireless communication devices, the first RSMA message comprising a first common part and multiple private parts associated with each of the plurality of wireless communication devices, the first common part encoding multiple portions associated with each of the plurality of wireless communication devices, and

[0138] - upon at least one of the plurality of wireless communication devices failing to decode the first common part, transmitting (3120) a second RSMA message to the plurality of wireless communication devices, the second RSMA message comprising a second common part, the second common part encoding an ARQ information for the first common part.

[0139] EXAMPLE 7. The method of EXAMPLE 6, further comprising:

[0140] - obtaining an indication (4010) that two or more (121, 122) of the plurality of wireless communication devices (121, 122, 123) failed to decode the first common part (230), wherein two or more portions (213, 223) of the second common part (230) associated with the two or more (121, 122) of the plurality of wireless communication devices (121, 122, 123) that failed to decode the first common part (230) comprise the ARQ information (4200).

[0141] EXAMPLE 8. The method of EXAMPLE 7,

[0142] wherein the two or more portions (213, 223) of the second common part 8230) associated with the two or more (121, 122) of the plurality of wireless communication devices (121, 122, 123) that failed to decode the first common part (230) comprise respectively different fractions (4201, 4202) of the ARQ information (4200).

[0143] EXAMPLE 9. The method of EXAMPLE 7 or 8,

[0144] wherein the at least one further portion of the second common part associated with at least another one of the plurality of wireless communication devices different than the two or more of the plurality of wireless communication devices that failed to decode the first common part carries payload data for the at least another one of the plurality of wireless communication devices.

[0145] EXAMPLE 10. The method of any one of EXAMPLES 6 to 9, further comprising:

[0146] - obtaining an indication that at least one of the plurality of wireless communication devices failed to decode the first common part, and

[0147] - configuring a size of the ARQ information based on a count of the at least one of the plurality of wireless communication devices.

[0148] EXAMPLE 11. The method of any one of the preceding EXAMPLES,

[0149] wherein the ARQ information comprises incremental redundancy information of the first common part.

[0150] EXAMPLE 12. The method of any one of the preceding EXAMPLES,

[0151] wherein the ARQ information comprises a redundancy version of the first common part. EXAMPLE 13. The method of any one of the preceding EXAMPLES, further comprising: - establishing a configuration of the RSMA transmission, the configuration being indicative a scheme for communicating the ARQ information.

[0152] EXAMPLE 14. The method of EXAMPLE 13,wherein the scheme for communicating the ARQ information is indicative of how the ARQ information is fractioned and distributed across multiple portions of the common part.

[0153] EXAMPLE 15. A wireless communication device (121) configured for communicating with a cellular network (119) using a rate-splitting multiple access, RSMA, transmission (140) protected by an automatic repeat request, ARQ, scheme (180), the wireless communication device (121) comprising a control circuitry configured to:

[0154] - receive (3005) a first RSMA message (299, 4250) comprising a first common part (230), a first private part (212) associated with the wireless communication device (121) and one or more further first private parts (222, 232) associated with one or more further wireless communication devices (122, 123), the first common part (230) encoding a portion (213) associated with the wireless communication device (121) and further encoding one or more further portions (223, 233) associated with the one or more further wireless communication devices (122, 123), and

[0155] - upon failing to decode the first common part, receive (3020) a second RSMA message (299, 4251) comprising a second common part (230), the second common part (230) encoding ARQ information (4200) of the first common part (230).

[0156] EXAMPLE 16. The wireless communication device (121) of EXAMPLE 15, wherein the control circuitry is configured to execute the method of EXAMPLES 1 to 5 or 11 to 14.

[0157] EXAMPLE 17. An access node (120) for a cellular network (119), the cellular network (119) configured for communicating with a plurality of wireless communication devices (121, 122, 123) using a rate-splitting multiple access, RSMA, transmission (140) protected by an automatic repeat request, ARQ, scheme (180), the access node comprising a control circuitry configured to:

[0158] - transmitting (3105) a first RSMA message to the plurality of wireless communication devices, the first RSMA message comprising a first common part and multiple private parts associated with each of the plurality of wireless communication devices, the first common part encoding multiple portions associated with each of the plurality of wireless communication devices, and

[0159] - upon at least one of the plurality of wireless communication devices failing to decode the first common part, transmitting (3120) a second RSMA message to the plurality of wireless communication devices, the second RSMA message comprising a second common part, the second common part encoding an ARQ information for the first common part.

[0160] EXAMPLE 18. The access node (120) of EXAMPLE 17, the control circuitry configured for executing the method of any one of EXAMPLES 6 to 14.

[0161] EXAMPLE 19. A wireless communication system (100) comprising the access node of EXAMPLE 17 and the wireless communication device (121) of EXAMPLE 15.

[0162] Although the invention has been shown and described with respect to certain preferred embodiments, equivalents and modifications will occur to others skilled in the art upon the reading and understanding of the specification. The present invention includes all such equivalents and modifications and is limited only by the scope of the appended claims.

Claims

C L A I M S1. A method for use in a wireless communication device communicating with a cellular network using a rate-splitting multiple access, RSMA, transmission protected by an automatic repeat request, ARQ, scheme, the method comprising:- receiving a first RSMA message comprising a first common part, a first private part associated with the wireless communication device and one or more further first private parts associated with one or more further wireless communication devices, the first common part encoding a portion associated with the wireless communication device and further encoding one or more further portions associated with the one or more further wireless communication devices, and- upon failing to decode the first common part, receiving a second RSMA message comprising a second common part, the second common part encoding ARQ information of the first common part.

2. The method of claim 1 ,wherein the RSMA transmission is based on predefined associations of the portions of the common parts of the RSMA messages to a plurality of wireless communication devices, wherein the portion of the second common part associated with the wireless communication device carries a fraction of the ARQ information,wherein at least one portion of the second common part associated with at least one of the one or more further wireless communication devices carries another fraction of the ARQ information.

3. The method of claim 2, further comprising:- upon failing to decode the first common part, obtaining an indicator indicative of the at least one portion of the second common part associated with the at least one of the one or more further wireless communication devices carrying the another fraction of the ARQ information.

4. The method of claim 3,wherein the indicator is included in a scheduling message that schedules resources for the second RSMA message.

5. The method of claim 2,wherein at least one further portion of the second common part associated with at least one further of the one or more wireless communication devices carries payload data for the at least one further of the one or more wireless communication devices.

6. A method for use in an access node of a cellular network, a plurality of wireless communication devices communicating with the cellular network through the access node using a rate-splitting multiple access, RSMA, transmission protected by an automatic repeat request, ARQ, scheme, the method comprising:- transmitting a first RSMA message to the plurality of wireless communication devices, the first RSMA message comprising a first common part and multiple private parts associated with each of the plurality of wireless communication devices, the first common part encoding multiple portions associated with each of the plurality of wireless communication devices, and- upon at least one of the plurality of wireless communication devices failing to decode the first common part, transmitting a second RSMA message to the plurality of wireless communication devices, the second RSMA message comprising a second common part, the second common part encoding an ARQ information for the first common part.

7. The method of claim 6, further comprising:- obtaining an indication that two or more of the plurality of wireless communication devices failed to decode the first common part,wherein two or more portions of the second common part associated with the two or more of the plurality of wireless communication devices that failed to decode the first common part comprise the ARQ information.

8. The method of claim 7,wherein the two or more portions of the second common part 8230) associated with the two or more of the plurality of wireless communication devices that failed to decode the first common part comprise respectively different fractions of the ARQ information.

9. The method of claim 7,wherein the at least one further portion of the second common part associated with at least another one of the plurality of wireless communication devices different than the two or more of the plurality of wireless communication devices that failed to decode the first common part carries payload data for the at least another one of the plurality of wireless communication devices.

10. The method of claim 6, further comprising:- obtaining an indication that at least one of the plurality of wireless communication devices failed to decode the first common part, and- configuring a size of the ARQ information based on a count of the at least one of the plurality of wireless communication devices.

11. The method of claim 1,wherein the ARQ information comprises incremental redundancy information of the first common part.

12. The method of claim 1 ,wherein the ARQ information comprises a redundancy version of the first common part.

13. The method of any one of the preceding claim 1 , further comprising:- establishing a configuration of the RSMA transmission, the configuration being indicative a scheme for communicating the ARQ information.

14. The method of claim 13,wherein the scheme for communicating the ARQ information is indicative of how the ARQ information is fractioned and distributed across multiple portions of the common part.

15. A wireless communication device configured for communicating with a cellular network using a rate-splitting multiple access, RSMA, transmission protected by an automatic repeat request, ARQ, scheme, the wireless communication device comprising a control circuitry configured to:- receive a first RSMA message comprising a first common part, a first private part associated with the wireless communication device and one or more further first private partsassociated with one or more further wireless communication devices, the first common part encoding a portion associated with the wireless communication device and further encoding one or more further portions associated with the one or more further wireless communication devices, and- upon failing to decode the first common part, receive a second RSMA message comprising a second common part, the second common part encoding ARQ information of the first common part.

16. An access node for a cellular network, the cellular network configured for communicating with a plurality of wireless communication devices using a rate-splitting multiple access, RSMA, transmission protected by an automatic repeat request, ARQ, scheme, the access node comprising a control circuitry configured to:- transmitting a first RSMA message to the plurality of wireless communication devices, the first RSMA message comprising a first common part and multiple private parts associated with each of the plurality of wireless communication devices, the first common part encoding multiple portions associated with each of the plurality of wireless communication devices, and - upon at least one of the plurality of wireless communication devices failing to decode the first common part, transmitting a second RSMA message to the plurality of wireless communication devices, the second RSMA message comprising a second common part, the second common part encoding an ARQ information for the first common part.

17. A wireless communication system, comprising an access node for a cellular network, the cellular network configured for communicating with a plurality of wireless communication devices using a rate-splitting multiple access, RSMA, transmission protected by an automatic repeat request, ARQ, scheme, and a wireless communication device configured for communicating with the cellular network using the rate-splitting multiple access, RSMA, transmission protected by an automatic repeat request, ARQ, scheme,the access node comprising a control circuitry configured to:- transmitting a first RSMA message to the plurality of wireless communication devices, the first RSMA message comprising a first common part and multiple private parts associated with each of the plurality of wireless communication devices, the first common part encoding multiple portions associated with each of the plurality of wireless communication devices, and - upon at least one of the plurality of wireless communication devices failing to decode the first common part, transmitting a second RSMA message to the plurality of wireless communication devices, the second RSMA message comprising a second common part, the second common part encoding an ARQ information for the first common part,the wireless communication comprising a control circuitry configured to:- receive the first RSMA message comprising the first common part, the first private part associated with the wireless communication device and one or more further first private parts associated with one or more further wireless communication devices, the first common part encoding a portion associated with the wireless communication device and further encoding one or more further portions associated with the one or more further wireless communication devices, and- upon failing to decode the first common part, receive the second RSMA message comprising a second common part, the second common part encoding ARQ information of the first common part.

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