EP4378094A1

EP4378094A1 - Client device and network access node for transport block based channel reporting

Info

Publication number: EP4378094A1
Application number: EP21754968.2A
Authority: EP
Inventors: Thorsten Schier; Shurong Jiao; Ruijie LI
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-08-03
Filing date: 2021-08-03
Publication date: 2024-06-05
Also published as: WO2023011705A1; CN117795876A

Abstract

The disclosure relates to a client device (100) and a network access node (300) for transport block based channel reporting. The client device (100) receives a set of PDSCH repetitions of a transport block. Based on a channel report configuration, the client device (100) determines a channel report by e.g. decoding the PDSCH repetitions indicated by the channel report configuration. The channel report is thereafter transmitted to the network access node (300) which uses the channel report and information about the channel report configuration for determining transmission parameters for the next transmission of PDSCH repetitions to the client device (100). Thereby, improved throughput is possible in the communication system. Furthermore, the disclosure also relates to corresponding methods and a computer program.

Description

CLIENT DEVICE AND NETWORK ACCESS NODE FOR TRANSPORT BLOCK BASED

CHANNEL REPORTING

Technical Field

Embodiments of the disclosure relate to a client device and a network access node for transport block based channel reporting in a communication system. Furthermore, embodiments of the disclosure also relate to corresponding methods and a computer program.

Background

In 3GPP 5G communication systems, also called new radio (NR), two transmission mechanisms are used, i.e. link adaptation and physical downlink shared channel (PDSCH) repetition.

Link adaption plays an important role in wireless communication systems such as NR. The scheduler at a next generation NodeB (gNB) takes the radio conditions perceived by a user equipment (UE) into account when selecting transmission resources. The better the radio conditions, the more aggressive can the scheduler's decision be in order to keep a certain reliability. Hence, less redundancy is added to protect data transmissions which increases the system capacity in terms of number of supported UEs and/or in terms of throughput to a given UE. In order to enhance the outer-loop link adaptation, 3GPP has recently started (in Rel-17) to study channel reporting based on PDSCH measurements.

PDSCH repetition on the other hand is a mechanism that has been designed to increase the reliability and/or coverage of ultra-reliable and low latency communication (URLLC) services. With PDSCH repetition a preconfigured number of multiple copies with the same or different redundancy versions of the same TB are sent to the UE on different PDSCHs upon one scheduling decision in case of dynamic transmission, or during one series of semi-persistent scheduling (SPS) occasions. During the decoding of PDSCH repetitions, the UE will typically combine the decoding results from the different copies of the TB to enhance the likelihood of a successful detection. The UE only has to decode as many copies as needed until it has successfully decoded the TB.

In case the UE will not be able to correctly decode a TB using all PDSCH repetitions, the UE will send a negative acknowledgment (NACK) to the gNB which typically invokes a retransmission. In case the TB is decoded correctly the UE will send an acknowledgment (ACK) after the last PDSCH repetition has been received. If the UE has decoded the TB correctly before the last PDSCH repetition, the UE can skip to decode the remaining copies. This is also what the UE typically would do to save power. For the gNB, it has no information of the decoding and channel information of the UE.

Summary

An objective of embodiments of the disclosure is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions.

Another objective of embodiments of the disclosure is to provide a communication system having a higher throughput and better spectral efficiency compared to conventional systems.

The above and further objectives are solved by the subject matter of the independent claims. Further advantageous embodiments of the disclosure can be found in the dependent claims.

According to a first aspect of the disclosure, the above mentioned and other objectives are achieved with a client device for a communication system, the client device being configured to receive a set of physical downlink shared channel, PDSCH, repetitions of a transport block transmission from a network access node; determine a channel report for the transport block transmission based on a channel report configuration, wherein the channel report configuration indicates which PDSCH repetitions in the set of PDSCH repetitions that are used by the client device for determining the channel report; and transmit the channel report to the network access node.

The channel report configuration comprises or indicates information how the client device should determine the channel report for the transport block transmission in respect of used PDSCH repetitions. The set of PDSCH repetitions may include one or more PDSCH repetitions. The number of PDSCH repetitions used for determining the channel report is given by the channel report configuration and may include one or more PDSCH repetitions depending on the application.

The channel report can for example be a channel state information (CSI), an achievable modulation and coding scheme (MCS), or channel quality indicator (CQI), and may be represented by e.g. delta-MCS, delta-CQI or any other suitable metric. An advantage of the client device according to the first aspect is that important schemes to enhance the performance for LIRLLC applications, such as improved link adaptation based PDSCH reception result, PDSCH repetition or also re-transmissions due to negative HARQ feedback, can be operated together. Another advantage is that it also allows PDSCH based reporting for HARQ re-transmission regardless of PDSCH repetitions or just a single PDSCH is used.

In an implementation form of a client device according to the first aspect, the channel report configuration indicates that only the first PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report; or only the last PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report.

According to this implementation form only the first or only the last PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report.

An advantage with this implementation form is that it is easy to implement. Also, this implementation form may be implemented as a generic solution that is independent from the number of PDSCHs that are contained in PDSCH repetition, e.g. regardless whether there is only one or multiple PDSCHs. Also, the channel report may be sent as early as possible to the network access node which gives the network access node some processing time margin to take the report into account when the network access node determines the parameters of the next transmission.

In an implementation form of a client device according to the first aspect, the channel report configuration indicates that the n-th PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report.

The n-th PDSCH repetition denotes the n-th PDSCH repetition index and may have the value between 2, 3,... , N where N denotes the total number of PDSCH repetitions in the set of PDSCH repetitions.

An advantage with this implementation form is that it provides flexibility to the network to configure or indicate suitable repetition numbers for the given requirements. It is a trade off between available processing time margin at the network access node side and actuality of the channel report. With a large value, e.g. with value N or a value close to N, very up-to-date channel information is obtained which provides the scheduler with better information to select a suitable MCS.

In an implementation form of a client device according to the first aspect, the channel report configuration further indicates that at least one previous PDSCH repetition in the set of PDSCH repetitions is used together with the n-th PDSCH repetition for determining the channel report.

Hence, with this implementation form two or more PDSCH repetition may be used for determining the channel report.

An advantage with this implementation form is that it is consistent in client device implementation with PDSCH decoding. Also, for PDSCH decoding, multiple PDSCHs for the same TB may be combined to increase the probability for a successful reception. Another advantage is that more data is used to obtain the channel report, which results in more accurate channel reports.

In an implementation form of a client device according to the first aspect, the client device is configured to receive a first control message from the network access node, the first control message indicating the channel report configuration.

An advantage with this implementation form is that the client device may be dynamically configured by the network via the network access node. This e.g. allows for more flexibility and gives the possibility to dynamically adopt to processing load at the network access node or to varying channel conditions.

In an implementation form of a client device according to the first aspect, the channel report configuration is at least partially pre-configured in the client device.

An advantage with this implementation form is that it requires less signalling and also avoids the risk of otherwise missing the reception of dynamical transmitted control information.

In an implementation form of a client device according to the first aspect, the channel report configuration is at least partially pre-configured in the client device and dependent on a decoding outcome of the transport block. The decoding outcome may e.g. be successful decoding, not successful decoding, first successful decoding, etc.

An advantage with this implementation form is that the client device does not to perform further measurements on later PDSCHs once it has correctly received the TB. This saves power and is also consistent with the PDSCH decoding in case of PDSCH repetition, where the client device does not need to decode the remaining repetitions after a successful reception.

In an implementation form of a client device according to the first aspect, the client device is configured to transmit a second control message to the network access node, the second control message indicating the channel report configuration.

An advantage with this implementation form is that the network access node is informed about the channel report configuration used by the client device, which is for example important if the network wants to treat received reports consistently.

In an implementation form of a client device according to the first aspect, the channel report configuration further indicates which HARQ transmissions in a set of HARQ transmissions that are used for the channel report.

Thereby, also HARQ transmissions are considered when informing about the channel conditions of the client device. Hence, also improved information in the outer loop link adaptation is provided for re-transmission triggered by a negative HARQ feedback, i.e. when the previous transmission of the TB could not be successfully decoded and the HARQ feedback mechanism sends a NACK to the network access node.

According to a second aspect of the disclosure, the above mentioned and other objectives are achieved with a network access node for a communication system, the network access node being configured to transmit a set of PDSCH repetitions of a transport block transmission to a client device; receive a channel report for the transport block transmission from the client device, the channel report being determined based on a channel report configuration, wherein the channel report configuration indicates which PDSCH repetitions in the set of PDSCH repetitions that are used by the client device for determining the channel report; and determine one or more transmission parameters for a subsequent transmission of a set of PDSCH repetitions based on the channel report. The one or more transmission parameters are used for the transmission of the subsequent transmission of a set of PDSCH repetitions. Hence, the transmission parameters may relate to the MCS, to the frequency domain resources (e.g. PRBs), to the time domain resources (e.g. OFDM symbols) or transmission on certain pre-configured sets on transmission resources, e.g. on different semi-statically configured PDSCH transmission sets.

An advantage of the network access node according to the second aspect is that important schemes to enhance the performance for LIRLLC applications, such as improved link adaptation based PDSCH reception result, PDSCH repetition or also re-transmissions due to negative HARQ feedback, can be operated together. Another advantage is that it also allows PDSCH based reporting for HARQ re-transmission regardless of PDSCH repetitions or just a single PDSCH is used.

In an implementation form of a network access node according to the second aspect, the channel report configuration indicates that only the first PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report; or only the last PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report.

In an implementation form of a network access node according to the second aspect, the channel report configuration indicates that the n-th PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report.

In an implementation form of a network access node according to the second aspect, the channel report configuration further indicates that at least one previous PDSCH repetition in the set of PDSCH repetitions is used together with the n-th PDSCH repetition for determining the channel report.

In an implementation form of a network access node according to the second aspect, the network access node is configured to transmit a first control message to the client device, the first control message indicating the channel report configuration.

In an implementation form of a network access node according to the second aspect, the network access node is configured to receive a second control message from the client device, the second control message indicating the channel report configuration.

In an implementation form of a network access node according to the second aspect, the channel report configuration further indicates which HARQ transmissions in a set of HARQ transmissions that are used for the channel report. Thereby, also HARQ transmissions are considered when informing about the channel conditions of the client device. Hence, also improved information in the outer loop link adaptation is provided for re-transmission triggered by a negative HARQ feedback, i.e. when the previous transmission of the TB could not be successfully decoded and the HARQ feedback mechanism sends a NACK to the network access node.

According to a third aspect of the disclosure, the above mentioned and other objectives are achieved with a method for a client device, the method comprises: receiving a set of physical downlink shared channel, PDSCH, repetitions of a transport block transmission from a network access node; determining a channel report for the transport block transmission based on a channel report configuration, wherein the channel report configuration indicates which PDSCH repetitions in the set of PDSCH repetitions that are used by the client device for determining the channel report; and transmitting the channel report to the network access node.

The method according to the third aspect can be extended into implementation forms corresponding to the implementation forms of the client device according to the first aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the client device.

The advantages of the methods according to the third aspect are the same as those for the corresponding implementation forms of the client device according to the first aspect.

According to a fourth aspect of the disclosure, the above mentioned and other objectives are achieved with a method for a network access node, the method comprises: transmitting a set of PDSCH repetitions of a transport block transmission to a client device; receiving a channel report for the transport block transmission from the client device, the channel report being determined based on a channel report configuration, wherein the channel report configuration indicates which PDSCH repetitions in the set of PDSCH repetitions that are used by the client device for determining the channel report; and determining one or more transmission parameters for a subsequent transmission of a set of PDSCH repetitions based on the channel report.

The method according to the fourth aspect can be extended into implementation forms corresponding to the implementation forms of the network access node according to the second aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the network access node.

The advantages of the methods according to the fourth aspect are the same as those for the corresponding implementation forms of the network access node according to the second aspect.

According to a fifth aspect of the disclosure, the above mentioned and other objectives are achieved with a client device for a communication system, the client device being configured to receive a set of HARQ transmissions of a transport block transmission from a network access node; determine a channel report for the transport block transmission based on a channel report configuration, wherein the channel report configuration indicates which HARQ transmissions in the set of HARQ transmissions that are used by the client device for determining the channel report; and transmit the channel report to a network access node.

The set of HARQ transmissions may include an initial transmission, first re-transmission, second re-transmission, etc.

According to a sixth aspect of the disclosure, the above mentioned and other objectives are achieved with a network access node for a communication system, the network access node being configured to transmit a set of HARQ transmissions of a transport block transmission to a client device; receive a channel report for the transport block transmission from the client device, the channel report being determined based on a channel report configuration, wherein the channel report configuration indicates which HARQ transmissions in the set of HARQ transmissions that are used by the client device for determining the channel report; and determine one or more transmission parameters for a subsequent transmission of a set of PDSCH repetitions based on the channel report.

According to a seventh aspect of the disclosure, the above mentioned and other objectives are achieved with a method for a client device, the method comprising receiving a set of HARQ transmissions of a transport block transmission from a network access node; determining a channel report for the transport block transmission based on a channel report configuration, wherein the channel report configuration indicates which HARQ transmissions in the set of HARQ transmissions that are used by the client device for determining the channel report; and transmitting the channel report to a network access node.

According to an eight aspect of the disclosure, the above mentioned and other objectives are achieved with a method for a network access node, the method comprising transmitting a set of HARQ transmissions of a transport block transmission to a client device; receiving a channel report for the transport block transmission from the client device, the channel report being determined based on a channel report configuration, wherein the channel report configuration indicates which HARQ transmissions in the set of HARQ transmissions that are used by the client device for determining the channel report; and determining one or more transmission parameters for a subsequent transmission of a set of PDSCH repetitions based on the channel report.

The disclosure also relates to a computer program, characterized in program code, which when run by at least one processor causes said at least one processor to execute any method according to embodiments of the disclosure. Further, the disclosure also relates to a computer program product comprising a computer readable medium and said mentioned computer program, wherein said computer program is included in the computer readable medium, and comprises of one or more from the group: ROM (Read-Only Memory), PROM (Programmable ROM), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically EPROM) and hard disk drive.

Further applications and advantages of the embodiments of the disclosure will be apparent from the following detailed description.

Brief Description of the Drawings

The appended drawings are intended to clarify and explain different embodiments of the disclosure, in which:

- Fig. 1 shows an example of channel tracking based on delta-MCS reports;

- Fig. 2 shows that using different number of PDSCH repetitions to obtain channel status information can lead to different results;

- Fig. 3 shows a client device according to an embodiment of the disclosure;

- Fig. 4 shows a method for a client device according to an embodiment of the disclosure; - Fig. 5 shows a network access node according to an embodiment of the disclosure;

- Fig. 6 shows a method for a network access node according to an embodiment of the disclosure;

- Fig. 7 shows a communication system according to an embodiment of the disclosure;

- Fig. 8 illustrates different signalling schemes for channel reporting;

- Fig. 9 shows a signalling diagram according to an embodiment of the disclosure; and

- Fig. 10 shows a signalling diagram according to a further embodiment of the disclosure.

Detailed Description

Previously, link adaptation and PDSCH repetition in NR was briefly discussed. Link adaptation usually comprises of an inner loop which typically is channel state information reference signal (CSI-RS) based and an outer-loop which is HARQ-ACK/NACK based.

The gNB scheduler has an estimate about e.g. the signal to noise and interference ratio (SINR) or another channel metric that can be used at the receiver (i.e. UE) and uses the SINR for resource selection/allocation when for example a transport block (TB) shall be sent in a PDSCH to the UE.

The inner loop component of the SINR is typically based on measurements that the UE performs on predefined reference symbols (RSs), such as the mentioned CSI-RS. The outerloop on the other hand is typically based on HARQ-ACK which means that if the received PDSCH has been decoded correctly, the UE will send an ACK to the gNB. The gNB uses this information and will increase the assumed SINR for scheduling with some (typically small) offset. This means that for each successfully transmitted and received PDSCH, the gNB will make the next scheduling slightly more aggressive, i.e. a higher modulation and coding scheme (MCS) will be selected for transmissions to the UE. This gradually improves the spectrum efficiency but also increases the risk of a transmission failure for the next subsequent transmission.

Once a PDSCH decoding has failed, the UE will send a NACK to the gNB which means that the gNB will decrease the SINR for the scheduling with a (typically large) offset. As a result, a much more conservative scheduling decision will be made for the transmission of the next PDSCH, i.e. the next PDSCH would be scheduled with a (much) lower MCS.

The above-described outer loop link adaptation concept works well for enhanced mobile broadband (eMBB) where the block error rate (BLER) of TBs typically is set to 10%. That means that in average, out of 10 HARQ-ACK feedbacks, there are 9 small SINR increments when an ACK is received at the gNB and 1 larger decrement when a NACK is received at the gNB. However, for LIRLLC it is extremely important to guarantee a very high reliability, i.e. the radio packets shall in principle be decoded correctly and only failure rates in the order of 1e-5 or even lower are tolerable. The initial specifications for NR have therefore targeted to guarantee the high reliability requirements. This came at the cost of system capacity, e.g. in the number of supported devices and/or throughput. That means that in principle too many ACKs will be received compared to the number of NACKs. This unfavourable ratio of ACK/NACK makes the currently used outer-loop link adaptation performing badly for LIRLLC and enhancements are therefore needed.

One possibility is that the UE would measure the channel based on PDSCH decoding. The UE can for example obtain information about the decoding margin, i.e. how easy or difficult it was to decode a received PDSCH correctly. If the channel was really good, then there could be a large margin in the decoding and the UE could also have been scheduled with a more aggressive resource selection, a high MCS could have been selected. This would provide the gNB with more information and the gNB could update its scheduling decisions with a much better granularity than if it would be based on HARQ feedback.

The UE can provide additional information to the gNB. The UE may generate a so-called delta- MCS based on the PDSCH decoding and send the delta-MCS information to the gNB. The delta-MCS could either be sent together with the HARQ-ACK or on separate control resources depending on application. Delta-MCS is used as the reported channel status for the UE and may be represented by an integer value. It shall however be understood that this is for exemplary purposes only and other reporting metrics, such as delta-CQI or any other suitable metric shall not be precluded. Also, it may be assumed for exemplary purposes that the UE calculates the SINR based on the PDSCH decoding to obtain a channel estimate. However, other measures to obtain the channel estimate to base the delta-MCS on shall not be precluded, such as log likelihood ratio (LLR), raw bit error rate (BER), flipped bits, low density parity check (LDPC) iterations, BLEP, number of fail parity checks, etc.

The delta-MCS may be used by the gNB to track the radio conditions at the UE and to utilize this information for efficient scheduling of TBs that are transmitted to the UE. The purpose is to provide additional information to the gNB that cannot be conveyed in the conventional HARQ-ACK signalling. An example is given in Fig. 1 in which the SNIR as a function of time at the UE is shown. When TB1 is received with MCS 10 by the UE the channel conditions are such that TB1 can be decoded, but the margin is low, i.e. the SINR is low. Therefore, the UE sends delta-MCS=O to the gNB. The next TB2 is therefore also scheduled with MCS 10. However, the channel conditions have improved at the UE and TB2 is decoded with a larger margin by the UE. Therefore, delta-MCS=+1 is sent to the gNB. As a response to the previously received delta-MCS=+1 , the gNB is scheduling the next TB3 with a higher MCS, i.e. MCS 11. Since the channel conditions have improved further, also TB3 can be decoded with good error margin and the UE again sends delta-MCS=+1 to the gNB. The gNB increases the MCS for scheduling and uses MCS 12 for scheduling of TB4. When the UE is decoding TB4, the channel conditions have however become worse at the UE, and the MCS used for transmission should be reduced, which means that the UE is sending a delta-MCS=-2 to the gNB so as to adapt to the changing channel condition.

A drawback with delta-MCS based channel tracking comes when re-transmissions or also PDSCH repetitions are used. It is important for URLLC that all these features shall be possible to operate together which is ensured with the present solution.

For PDSCH repetition, different copies of a TB, possibly with the same or different redundancy versions, are transmitted in a predefined manner. The UE only needs to decode as many PDSCH repetitions until it has detected the TB correctly.

Usually, when the UE is decoding the TB that is received during a PDSCH repetition other than the initial PDSCH repetition, the UE will combine the result with previous PDSCH repetitions to increase the signal power at the receiver and thereby to increase the likelihood of a successful decoding. In conventional solutions it is transparent to the gNB which and how many repetitions have been used by the UE to decode the TB.

This imposes a problem for the gNB when it has to use a delta-MCS report to schedule the next transmission to the UE, since delta-MCS reports that are based on a different number of PDSCH repetitions can be different from each other. This is true even if the underlying radio channel conditions are the same. Without further information, it is therefore impossible for the gNB to compare sub-sequent delta-MCS reports and to use them consistently to track the radio channel of the UE. This may lead to a not suitable scheduling decisions if sub-sequent delta- MCS reports are based on different numbers of repetitions.

An example to illustrate this problem is shown in Fig 2. Depending on how many PDSCH repetitions 1 , 2, 3,... , N are combined, the perceived channel status (e.g. SINR) at the UE will be different; and different channel information can mean that different delta-MCS values will be generated. As shown in Fig. 2 using PDSCH repetition with index n=1 results in delta- MCS=a; using PDSCH repetitions with index n=1 and index n=2 result in delta-MCS=b and so on.

To overcome the above drawbacks and problems of conventional solutions and to enable to efficiently use of PDSCH based channel estimation and reporting for PDSCH repetition, the following embodiments and implementations are herein disclosed.

Fig. 3 shows a client device 100 according to an embodiment of the disclosure. In the embodiment shown in Fig. 3, the client device 100 comprises a processor 102, a transceiver 104 and a memory 106. The processor 102 may be coupled to the transceiver 104 and the memory 106 by communication means 108 known in the art. The client device 100 may further comprise an antenna or antenna array 110 coupled to the transceiver 104, which means that the client device 100 may be configured for wireless communications in a wireless communication system. That the client device 100 may be configured to perform certain actions can in this disclosure be understood to mean that the client device 100 comprises suitable means, such as e.g. the processor 102 and the transceiver 104, configured to perform said actions.

The client device 100 in this disclosure includes but is not limited to: a UE such as a smart phone, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device having a wireless communication function, a computing device or another processing device connected to a wireless modem, an in-vehicle device, a wearable device, an integrated access and backhaul node (IAB) such as mobile car or equipment installed in a car, a drone, a device-to- device (D2D) device, a wireless camera, a mobile station, an access terminal, an user unit, a wireless communication device, a station of wireless local access network (WLAN), a wireless enabled tablet computer, a laptop-embedded equipment, an universal serial bus (USB) dongle, a wireless customer-premises equipment (CPE), and/or a chipset. In an Internet of things (IOT) scenario, the client device 100 may represent a machine or another device or chipset which performs communication with another wireless device and/or a network equipment.

The UE may further be referred to as a mobile telephone, a cellular telephone, a computer tablet or laptop with wireless capability. The UE in this context may e.g. be portable, pocket- storable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data, via the radio access network, with another entity, such as another receiver or a server. The UE can be a station (STA), which is any device that contains an IEEE 802.11 -conformant media access control (MAC) and physical layer (PHY) interface to the wireless medium (WM). The UE may also be configured for communication in 3GPP related LTE and LTE-Advanced, in WiMAX and its evolution, and in fifth generation wireless technologies, such as NR.

The processor 102 of the client device 100 may be referred to as one or more general-purpose central processing units (CPUs), one or more digital signal processors (DSPs), one or more application-specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more programmable logic devices, one or more discrete gates, one or more transistor logic devices, one or more discrete hardware components, and one or more chipsets. The memory 106 of the client device 100 may be a read-only memory, a random access memory, or a non-volatile random access memory (NVRAM). The transceiver 104 of the client device 100 may be a transceiver circuit, a power controller, an antenna, or an interface which communicates with other modules or devices. In embodiments, the transceiver 104 of the client device 100 may be a separate chipset or being integrated with the processor 102 in one chipset. While in some embodiments, the processor 102, the transceiver 104, and the memory 106 of the client device 100 are integrated in one chipset.

According to embodiments of the disclosure and with reference to Fig. 3 and 7, the client device 100 is configured to receive a set of PDSCH repetitions of a transport block transmission from a network access node 300. The client device 100 is configured to determine a channel report CHR for the transport block transmission based on a channel report configuration, wherein the channel report configuration indicates which PDSCH repetitions in the set of PDSCH repetitions that are used by the client device 100 for determining the channel report CHR. The client device 100 is configured to transmit the channel report CHR to the network access node 300.

Fig. 4 shows a flow chart of a corresponding method 200 which may be executed in a client device 100, such as the one shown in Fig. 3. The method 200 comprises receiving 202 a set of PDSCH repetitions of a transport block transmission from a network access node 300. The method 200 comprises determining 204 a channel report CHR for the transport block transmission based on a channel report configuration, wherein the channel report configuration indicates which PDSCH repetitions in the set of PDSCH repetitions that are used by the client device 100 for determining the channel report CHR. The method 200 comprises transmitting 206 the channel report CHR to the network access node 300.

Fig. 5 shows a network access node 300 according to an embodiment of the disclosure. In the embodiment shown in Fig. 5, the network access node 300 comprises a processor 302, a transceiver 304 and a memory 306. The processor 302 is coupled to the transceiver 304 and the memory 306 by communication means 308 known in the art. The network access node 300 may be configured for both wireless and wired communications in wireless and wired communication systems, respectively. The wireless communication capability is provided with an antenna or antenna array 310 coupled to the transceiver 304, while the wired communication capability is provided with a wired communication interface 312 coupled to the transceiver 304. That the network access node 300 is configured to perform certain actions can in this disclosure be understood to mean that the network access node 300 comprises suitable means, such as e.g. the processor 302 and the transceiver 304, configured to perform said actions.

The network access node 300 in this disclosure includes but is not limited to: a NodeB in wideband code division multiple access (WCDMA) system, an evolutional Node B (eNB) or an evolved NodeB (eNodeB) in LTE systems, or a relay node or an access point, or an in-vehicle device, a wearable device, or a gNB in the fifth generation (5G) networks. Further, the network access node 300 herein may be denoted as a radio network access node, an access network access node, an access point, or a base station, e.g. a radio base station (RBS), which in some networks may be referred to as transmitter, “gNB”, “gNodeB”, “eNB”, “eNodeB”, “NodeB” or “B node”, depending on the technology and terminology used. The radio network access nodes may be of different classes such as e.g. macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby also cell size. The radio network access node can be a station (STA), which is any device that contains an IEEE 802.11 -conformant MAC and PHY interface to the wireless medium. The radio network access node may also be a base station corresponding to the 5G wireless systems.

The processor 302 of the network access node 300 may be referred to as one or more general- purpose CPUs, one or more DSPs, one or more ASICs, one or more FPGAs, one or more programmable logic devices, one or more discrete gates, one or more transistor logic devices, one or more discrete hardware components, and one or more chipsets. The memory 306 of the network access node 300 may be a read-only memory, a random access memory, or a NVRAM. The transceiver 304 of the network access node 300 may be a transceiver circuit, a power controller, an antenna, or an interface which communicates with other modules or devices. In embodiments, the transceiver 304 of the network access node 300 may be a separate chipset or being integrated with the processor 302 in one chipset. While in some embodiments, the processor 302, the transceiver 304, and the memory 306 of the network access node 300 are integrated in one chipset. According to embodiments of the disclosure and with reference to Fig. 5 and 7 the network access node 300 is configured to transmit a set of PDSCH repetitions of a transport block transmission to a client device 100. The network access node 300 is configured to receive a channel report CHR for the transport block transmission from the client device 100, the channel report CHR being determined based on a channel report configuration, wherein the channel report configuration indicates which PDSCH repetitions in the set of PDSCH repetitions that are used by the client device 100 for determining the channel report CHR. The network access node 300 is configured to determine one or more transmission parameters for a subsequent transmission of a set of PDSCH repetitions based on the channel report CHR.

Fig. 6 shows a flow chart of a corresponding method 400 which may be executed in a network access node 300, such as the one shown in Fig. 5. The method 400 comprises transmitting 402 a set of PDSCH repetitions of a transport block transmission to a client device 100. The method 400 comprises receiving 404 a channel report CHR for the transport block transmission from the client device 100, the channel report CHR being determined based on a channel report configuration, wherein the channel report configuration indicates which PDSCH repetitions in the set of PDSCH repetitions that are used by the client device 100 for determining the channel report CHR. The method 400 comprises determining 406 one or more transmission parameters for a subsequent transmission of a set of PDSCH repetitions based on the channel report CHR.

Fig. 7 shows a communication system 500 according to an embodiment of the disclosure. The communication system 500 comprises a client device 100 and a network access node 300 configured to operate in the wireless communication system 500. For simplicity, the communication system 500 shown in Fig. 7 only comprises one client device 100 and one network access node 300. However, the communication system 500 may comprise any number of client devices 100 and any number of network access nodes 300 without deviating from the scope of the disclosure.

The network access node 300, such as a gNB, may be part of a radio access network (RAN) that is connected to a core network (CN). The communication between the network access node 300 and the client device 100 may be performed over a downlink (DL) interface from the network access node 300 to the client device and an uplink (UL) interface from the client device 100 to the access network node 300. The network access node 300 is configured to perform a TB transmission by transmitting a set of PDSCH repetitions of a TB transmission to the client device 100. The total number of repetitions N may be defined by a standard. The client device 100 is according to the present solution configured with a channel report configuration which PDSCH repetitions the UE should use for determining a channel report, such as delta-MCS or delta-CQI.

In the following disclosure further embodiments and examples will be described in a 3GPP 5G context hence the terminology, expressions, protocols, system architecture used. Therefore, a client device will be denoted UE and a network access node a gNB. It should however be noted that embodiments of the disclosure are not limited thereto.

In embodiments of the disclosure, the channel report configuration indicates that only the first PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report. Hence, it is specified that the channel report is obtained only on the first PDSCH repetition. This has the advantage that it is very simple to implement in the UE and different channel reports can be easily compared with each other. A drawback with this approach is the delay between channel measurement and when it is received and applied at the gNB. Since the first PDSCH repetition is the least recent PDSCH repetition in the set of PDSCH repetitions, there is a risk that the channel information conveyed in the channel report already is outdated when it shall be applied by the gNB.

The channel report obtained from the PDSCH based channel measurement which could be delta-MCS, delta-CQI or any other suitable measure, can for example be signalled by the UE as shown in Fig. 8:

A. In a specific dedicated physical uplink control channel (PUCCH) directly after the first PDSCH repetition has been received and decoded;

B. The channel report can in another case be multiplexed with other uplink control information (UCI) in the PUCCH. The other UCI may e.g. relate to HARQ feedback from other transport blocks, scheduling requests (SR) or other channel state information, e.g. obtained from measurements on CSI-RS, etc.

C. The channel report can be included in the PUCCH carrying HARQ feedback (e.g. ACK/NACK) for the PDSCH repetition transmission.

In embodiments of the disclosure, information about how the signalling of the channel report should be performed may also be comprised or indicated by the channel report configuration. In general, the signalling of the channel report may be pre-defined, or dynamically indicated (either implicitly or explicitly) as explained above.

In embodiments of the disclosure, only the last PDSCH repetition is used to obtain the channel information for the generation of the channel report. Hence, always the last configured PDSCH repetition, i.e. with PDSCH repetition index N, is used by the UE to obtain the channel information that the channel report is based on. An advantage of this approach is that always the freshest information is used and the risk for outdated channel state information is minimized. Also, this embodiment is simple to specify and implement. A drawback is that the UE might already have stopped the PDSCH decoding earlier. For the decoding operation of a TB, the UE is only expected to process as many PDSCH repetitions until it has successfully decoded the TB. If this is achieved before the N-th repetition, it will typically not pursue any more decoding. This means that the UE might have to go on with PDSCH decoding just for the purpose of channel measurement, which is not desirable from an implementation perspective e.g. in respect of power consumption and processing resources.

The signalling of the channel report can either be in a dedicated PUCCH or it can be multiplexed in the PUCCH with UCI or with HARQ-ACK feedback as discussed previously with reference to Fig. 8. The difference is that the channel report can only be transmitted to the gNB after the last PDSCH repetition has been received and processed by the UE.

In embodiments of the disclosure, the n-th PDSCH repetition is used for determining the channel report. Index n denotes the PDSCH repetition index and may have a value from 1 to N, i.e. n = 1 , 2, 3,... , N.

The n-th PDSCH repetition may be used alone or together with one or more previous PDSCH repetitions for determining the channel report. Therefore, in further embodiments of the disclosure, the n-th PDSCH repetition and at least one previous PDSCH repetition is used for determining the channel report. This means that two or more PDSCH repetitions are used by the UE for determining the channel report.

Further, the method of averaging may be applied when two or more PDSCH repetitions are used. In general, the averaging may be performed over all or an arbitrary subset of the used PDSCH repetitions. The averaging may further be performed between the first used PDSCH repetition and the first successfully decoded PDSCH repetition. The averaging may also be performed between the first used PDSCH repetition and last configured PDSCH repetition, and so on.

Hence, the PDSCH repetitions may be combined to obtain channel information for the generation of the channel report. However, all PDSCH repetitions that are used for determining the channel report may also be used individually without combining to obtain the channel report. Therefore, a reported delta-MCS can be based on the average of the individually obtained channel information or also each individually obtained delta-MCS report can be signalled separately. In the first case only one delta-MCS report is needed after the last configured PDSCH repetition. In the second case, an individual PLICCH carrying the channel report may be for each PDSCH repetition.

Moreover, the channel report may be reported/signalled for each PDSCH repetition from the first used PDSCH repetition until the last used PDSCH repetition. The delta-MCS can either be reported/signalled separately, e.g. one PLICCH for each delta-MCS, or they can be reported in one common channel report. The delta-MCS reports for PDSCH repetitions other than the first used PDSCH repetition, can e.g. be based only on the current PDSCH repetition or can be combined with previous PDSCH repetitions. Whether to combine different PDSCH repetitions or not can be pre-defined by the standard, can be semi-statically configured, e.g. by RRC signalling, or can be dynamically indicated, e.g. by DCI signalling.

In further implementations, all PDSCH repetitions up to the latest configured or indicated PDSCH repetition may be used individually without combining to obtain the channel report. For example, the reported delta-MCS can be determined based on the average of the individually obtained channel reports or also each individually obtained delta-MCS report can be signalled separately. In the first case only one delta-MCS report is needed after the last PDSCH repetition that is used. In the second case, an individual PLICCH is sent for each PDSCH repetition.

In embodiments of the disclosure, it is implicitly obtained which PDSCH repetition that is the latest repetition to be used for obtaining the channel estimation. The UE may obtain the latest repetition based on the PLICCH allocations to carry the delta-MCS report. All PDSCH repetitions that end before the start of the PLICCH may be used for calculating the channel report. For example, assume that N=4 repetitions are configured. The PLICCH which carries the channel report is configured after the third PDSCH and before the fourth PDSCH. Then, based on this information the UE can derive which PDSCHs the UE shall use to obtain the channel report. In one realization of this embodiment, the report will be based on the last (i.e. the second) PDSCH before the PUCCH (i.e. on the third); and in another realization it can combe the last PDSCH for the PUCCH with at least one earlier PDSCH.

In further embodiments of the disclosure, it is specified that is under the control of the gNB which PDSCH repetitions shall be used for determining the channel report by the UE. The gNB can in this respect send a first control message 510 to the UE for this purpose which is illustrated in Fig. 9. In step I in Fig. 9, the gNB configures the UE by transmitting a first control message 510 comprising a channel report configuration to the UE. The first control message 510 can e.g. be RRC signalling for semi-statically pre-configuration of the PDSCH repetitions to be used by the UE, or the UE can be dynamically configured via DCI signalling from the gNB. In embodiments of the disclosure, the channel report configuration may further include or indicate information and details about the signalling of the first control message 510. It may however be noted that the channel report configuration may in embodiments be pre-defined in the UE. In such cases the first control message 510 is not needed and the steps relating to transmission and reception of the first control message 510 are not performed.

In step II in Fig. 9, the UE receives the first control message 510 and derives the channel report configuration indicated or included in the first control message 510.

In step III in Fig. 9, the gNB transmit a set of PDSCH repetitions of a TB to the UE, e.g. in a downlink data channel. A PDSCH repetition may be understood as a preconfigured number of PDSCH repetitions is used to transmit the same TB. The PDSCH repetitions may e.g. be index from n = 1 , 2, 3,... , N. Possible different redundancy versions of the TB may be used in the different PDSCH repetitions.

In step IV in Fig. 9, the UE receives the set of PDSCH repetitions from the gNB. It should be noted that the UE is not required to decode any further PDSCH after it has successfully decoded the TB. Thus, even if the whole set of PDSCHs is transmitted to the UE, the UE might not need to receive all PDSCHs that are included in this set.

In step V in Fig. 9, the UE determines a channel report based on the set of PDSCH repetitions and according to the channel report configuration received in step II. For determining the channel report the UE firstly determines or estimates the radio channel. This may involve computing channel estimates based on reference signals (RSs) received from the gNB. Or this may be based on the decoding margin of the PDSCH, i.e. when the UE can determine that is was very easy to correctly the decode the TB, good channel conditions can be concluded, and if it was hard (close to an error) worse channel condition can be assumed. As a measure for the channel conditions, the UE can use the SINR based on the PDSCH decoding to obtain a channel estimate or also other measures such as log likelihood ratios (LLR), raw bit error rate (BER), number of flipped bits, low density parity check (LDPC) iterations, BLEP, number of failed parity checks, etc. Based on the channel estimates the UE can determine the channel report such as a delta-MCS. In step VI in Fig. 9, the UE transmits the determined channel report, such as a delta-MCS, to the gNB, e.g. in an uplink control channel.

In step VII in Fig. 9, the gNB receives the channel report from the UE and based on the channel report determines transmission parameters for the transmission of the next subsequent set of PDSCH repetitions to the UE.

Further, a HARQ procedure may be employed in the present system. Hence, in such case a HARQ-ACK/NACK is sent corresponding to the decoding result of the TB. This HARQ- ACK/NACK is sent by the UE after the last PDSCH repetition occasion. To distinguish from HARQ triggered re-transmission, all the repetitions belong to the same HARQ-feedback are regarded as one transmission. Re-transmissions may be triggered by HARQ-NACK feedback. A transmission or re-transmission can consist of one or multiple PDSCHs. In the latter case, the transmission is using PDSCH repetitions. The gNB may also receive HARQ-ACK/NACK feedback from the UE. If the UE transmits a NACK a re-transmission is triggered by the gNB.

The embodiment illustrated in Fig. 9 is flexible and the risk of outdated channel information can be reduced. It also offers more options how to process the different PDSCH repetitions, e.g. whether to combine them or to process them individually. A drawback with this embodiment may be that the UE might already have stopped decoding earlier due to a successful detection of the TB and would need to perform further operations just for the purpose of channel measurements.

The signalling of the channel report may be similar to the previous embodiment shown in Fig. 8.

In the following description embodiments in which the channel report configuration is further dependent on the decoding outcome at the UE are described.

In embodiments of the disclosure, the channel report is determined based on the PDSCH repetition that resulted into a successful decoding of the TB and/or on the last configured PDSCH repetition in case that the TB could not be successfully decoded. An advantage with this solution is that it can be at least partially pre-defined in a specification/standard and that no unnecessary operations, e.g. further decoding, are needed at the UE side. A drawback may be that the gNB needs to know which PDSCH repetitions have been used for obtaining the channel report. To solve this issue the UE can inform the gNB which PDSCH repetition number resulted into a successful decoding or in more general terms: i.e. the UE can inform the gNB about the channel report configuration that has been used by the UE for determining the channel report. Such embodiments are illustrated in Fig. 10.

In step I in Fig. 10, the gNB transmits a set of PDSCH repetitions of a TB transmission to the UE over a data channel.

In step II in Fig. 10, the UE receives the set of PDSCH repetitions and starts processing the set of PDSCH repetitions according to predefined procedures.

In step III in Fig. 10, the UE obtains a channel report configuration which e.g. may fully or at least partially be pre-configured in the UE. The channel report configuration may also be dependent on the decoding outcome of the TB. However, the gNB is not aware of the present channel report configuration used by the UE.

In step IV in Fig. 10, the UE therefore transmits a second control message 520 comprising or indicating the used channel report configuration to the gNB. This information can be signalled together with the channel report or on separate control resources. In embodiments of the disclosure, the channel report configuration may further include or indicate information and details about the signalling of the second control message 520.

In step V in Fig. 10, the gNB receives the second control message 520 and derives the channel report configuration from the second control message 520.

In step VI in Fig. 10, the UE determines a channel report CHR according to the channel report configuration and based on the received set of PDSCH repetitions. The determined channel report CHR is thereafter transmitted to the gNB.

In step VII in Fig. 10, the gNB based on the received channel report configuration and the channel report CHR determines transmission parameters for the transmission of the next subsequent set of PDSCH repetitions to the UE.

However, in alternative embodiments of the disclosure, the gNB can implicitly determine which PDSCH repetition(s) resulted into a successful decoding at the UE. For such cases, separate PUCCHs can be configured, each corresponding to a different PDSCH repetition. The UE may transmit the channel report on the PUCCH that corresponds to the PDSCH repetition that resulted into a successful PDSCH decoding. The gNB then performs blind detection on the possible occasions and thereby detects which PDSCH repetition led to a successful decoding. These embodiments require however more processing power and processing time due to the blind decoding steps.

As previously described, the channel report may be determined based on PDSCH repetitions that have been needed by the UE to successfully decode the TB. But since this number can vary from TB to TB and is unknown to the gNB, the UE may add different offset values to the channel report to compensate for the number of repetitions that were used. The offset values may e.g. be given in the specification, or the UE may determine the offset values autonomously and report them to the gNB. In another option, the UE may apply different offset values that are transparent to the gNB.

For example, if the TB already has been decoded correctly after the first PDSCH repetition, the decoding margin for this particular PDSCH repetition might be small and the delta-MCS may also be small, but there are still multiple PDSCH repetitions remaining that could have been used. To take such considerations into account, the UE could change the obtained channel information based on the number of remaining PDSCH repetitions after successful decoding. For example, if the TB is decoded correctly after the first PDSCH repetition, and there are one or several remaining PDSCH repetitions, the reported delta-MCS value may be increased with an offset value compared to the result which is based on the first PDSCH repetition only. In general, how much the reported delta-MCS value can be changed with an offset may depend on the number of remaining PDSCH repetitions after successful decoding.

How much the delta-MCS value is changed due to the offset value or the offset value per see, may be signalled by the gNB to the UE, or may be determined independently by the UE and reported to the gNB via suitable control signalling.

Yet another solution would be that the change of the delta-MCS by an offset is up to UE implementation and not reported nor signalled to the gNB. In this case it is up to the UE to ensure that channel reports are comparable (or compensated) regardless of how many PDSCH repetitions that have been used for determining the channel report(s). The latter approach would have drawbacks as it gives the gNB very little control to efficiently use this feature, though.

In yet further embodiments of the disclosure, the reported channel report is only based on the number of required PDSCH repetitions to successfully decode the TB. The fewer repetitions that were used, the better channel conditions can be assumed and the more aggressively the MCS used for transmission can be adjusted.

For example, if the TB has already been received successfully after the first repetition, a very good channel can be assumed and a larger delta-MCS can be reported. But if all PDSCH repetitions had to be used by the UE, then the channel conditions are not so good, and it is better to not further increase the delta-MCS. In this situation, i.e. after an ACK after the last PDSCH repetition, it might be better to keep the MCS on the same level as previously.

Following that logic, predefined values for the MCS can be used depending on the number of remaining PDSCH repetitions after the successful decoding. These predefined values could be specified in the specification, or semi-statically signalled from the gNB to the UE via RRC, or dynamically signalled from the gNB to the UE via DCI, or autonomously be obtained by the UE.

For example, for pre-defined values, if the ACK is after the last PDSCH repetition, the delta- MCS would be 0, it would mean that the MCS of the next TB shall not change. If there is one remaining PDSCH repetition that was not used for decoding, the MCS could be increased somewhat and the more PDSCH repetitions that were not needed, the more the MCS can be increased.

Aspects and embodiments of the disclosure also relates to the present channel reporting mechanism set when a HARQ procedure is employed in the system. The channel report configuration can indicate which HARQ transmissions among a set of HARQ transmissions that are to be used by the UE for determining the channel report. The set of HARQ transmissions includes: an initial transmission, a first re-transmission, a second retransmission, etc. until the last re-transmission. The number of re-transmissions may be dependent on the number of NACKs received and a pre-configured maximum number of retransmissions that often is defined by a standard.

It has previously been illustrated how the computed channel characteristics change if multiple PDSCH repetitions are combined for decoding at the UE, e.g. the SINR at the UE will be increased. The gNB should have information for a given delta-MCS report on how many PDSCHs it is based, or alternatively the UE should compensate the reports, if different channel reports can be based on different repetitions. The compensation may then be of such character that it is not necessary for the gNB to know the applied channel measurement configuration. If different configurations were used for different TBs (for example due to varying decoding outcomes), it may be up to the UE to ensure that different channel reports are comparable at the gNB side. Mechanisms to solve the above problem have been disclosed for PDSCH repetitions and it is understood that similar concepts also may be applied for HARQ retransmission(s). This is regardless of if the initial HARQ transmission is based on a single PDSCH repetition or on multiple PDSCH repetitions.

The concept of a re-transmission may be translated to the concept of PDSCH repetitions. This example is for the case if there is only one configured repetition, i.e. when N=1 , which can also be regarded as: no PDSCH repetition is used. However, the same is also valid for the case of PDSCH repetitions. In such situations, at least one of an initial transmission or a retransmission may include multiple PDSCH repetitions. If the initial transmission is not decoded correctly and consequently a NACK is sent to the gNB, the UE may still send a PDSCH based CSI report (e.g. containing delta-MCS) to the gNB. Thus, even if it is the typical case that delta- MCS reports are sent for successfully decoded TBs, there are also embodiments where a delta-MCS report is sent when the PDSCH decoding resulted into a NACK.

Based on reception of a NACK, the gNB will typically perform a re-transmission of an erroneously decoded TB according to the HARQ procedure. The UE will combine the received re-transmission with a previous transmission for which the decoding failed. Thus, similar to the case described for PDSCH repetitions, the channel report corresponding to the re-transmission might not be comparable with the channel report that only is based on the initial transmission and so on. In conventional solutions, the gNB is not aware of whether the channel report for the re-transmission is based only on the re-transmission or, similar to the PDSCH decoding, if it is based on the re-transmission and previous HARQ transmissions.

In an embodiment, it is specified that the PDSCH based CSI report (e.g. delta-MCS) is only based on the current HARQ (re)-transmission regardless if the current HARQ (re)-transmission is a single PDSCH with N=1 or a set of PDSCH repetitions with N>1. That means generally that different HARQ (re)-transmissions are not combined for the channel report. Within each HARQ (re)-transmission the rules and embodiments for the case of PDSCH repetitions described earlier in this disclosure apply regardless of the value of N. Hence, in embodiments of the disclosure, the channel report configuration may comprise or indicate information how the client device should determine the channel report for transport block transmission in respect of used PDSCH repetitions and/or potential HARQ re-transmissions.

From the above discussion it is implied that the principles and embodiments disclosed previously in regards of channel report and PDSCH repetitions are also applicable to HARQ transmissions. For example, only the initial transmission may be used, only the last retransmission may be used, or a combination of two or more HARQ transmissions for determining the channel report. To exemplify such aspects further the following non-limiting examples are given.

In embodiments of the disclosure, it is under the gNB control if the PDSCH based channel report, e.g. delta-MCS or delta-CQI, is obtained from different (re)-transmissions independently or if different re-transmissions shall be combined. The gNB can configure/instruct the UE for example semi-statically with RRC signalling or also dynamically indicated by DCI. It is understood that a (re)-transmission can consist of one PDSCH or, in case of PDSCH repetition of multiple PDSCH repetitions.

If the UE is instructed to combine multiple re-transmissions, the UE may compensate the channel report of the re-transmissions (e.g. by reducing the delta MCS) so that it can be compared with channel reports that are not based on the combination of different HARQ transmissions. Further, the UE may compensate the channel reports (e.g. by increasing the delta-MCS) that are only based on one single (re)-transmission.

In embodiments of the disclosure, it is up the UE to decide whether to combine multiple (re)- transmissions to obtain the channel report or not. The UE can signal this information to the gNB in control signalling, e.g. comprising a control message. The control signalling may be jointly encoded in the channel report, separately encoded but sent on the same physical channel as the channel report, or may be sent on a separate physical channel.

As previously, if the UE combines multiple re-transmissions, the UE may compensate the channel report of the re-transmissions (e.g. by reducing the delta MCS) so that it can be compared with channel reports that are not based on the combination of different transmissions. In another realization of this embodiment, the UE shall compensate the channel reports (e.g. by increasing the delta-MCS) that are only based on one single (re)-transmission.

Furthermore, any method according to embodiments of the disclosure may be implemented in a computer program, having code means, which when run by processing means causes the processing means to execute the steps of the method. The computer program is included in a computer readable medium of a computer program product. The computer readable medium may comprise essentially any memory, such as a ROM (Read-Only Memory), a PROM (Programmable Read-Only Memory), an EPROM (Erasable PROM), a Flash memory, an EEPROM (Electrically Erasable PROM), or a hard disk drive. Moreover, it is realized by the skilled person that embodiments of the client device 100 and the network access node 300 comprises the necessary communication capabilities in the form of e.g., functions, means, units, elements, etc., for performing the solution. Examples of other such means, units, elements and functions are: processors, memory, buffers, control logic, encoders, decoders, rate matchers, de-rate matchers, mapping units, multipliers, decision units, selecting units, switches, interleavers, de-interleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiver units, transmitter units, DSPs, MSDs, TCM encoder, TCM decoder, power supply units, power feeders, communication interfaces, communication protocols, etc. which are suitably arranged together for performing the solution.

Especially, the processor(s) of the client device 100 and the network access node 300 may comprise, e.g., one or more instances of a Central Processing Unit (CPU), a processing unit, a processing circuit, a processor, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions. The expression “processor” may thus represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones mentioned above. The processing circuitry may further perform data processing functions for inputting, outputting, and processing of data comprising data buffering and device control functions, such as call processing control, user interface control, or the like.

Finally, it should be understood that the disclosure is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the appended independent claims.

Claims

1. A client device (100) for a communication system (500), the client device (100) being configured to receive a set of physical downlink shared channel, PDSCH, repetitions of a transport block transmission from a network access node (300); determine a channel report (CHR) for the transport block transmission based on a channel report configuration, wherein the channel report configuration indicates which PDSCH repetitions in the set of PDSCH repetitions that are used by the client device (100) for determining the channel report (CHR); and transmit the channel report (CHR) to the network access node (300).

2. The client device (100) according to claim 1 , wherein the channel report configuration indicates that only the first PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report (CHR); or only the last PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report (CHR).

3. The client device (100) according to claim 1 , wherein the channel report configuration indicates that the n-th PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report (CHR).

4. The client device (100) according to claim 3, wherein the channel report configuration further indicates that at least one previous PDSCH repetition in the set of PDSCH repetitions is used together with the n-th PDSCH repetition for determining the channel report (CHR).

5. The client device (100) according to any one of the preceding claims, configured to receive a first control message (510) from the network access node (300), the first control message (510) indicating the channel report configuration.

6. The client device (100) according to any one of the preceding claims, wherein the channel report configuration is at least partially pre-configured in the client device (100).

29

7. The client device (100) according to claim 6, wherein the channel report configuration is at least partially pre-configured in the client device (100) and dependent on a decoding outcome of the transport block.

8. The client device (100) according to claim 7, configured to transmit a second control message (520) to the network access node (300), the second control message (520) indicating the channel report configuration.

9. The client device (100) according to any one of the preceding claims, wherein the channel report configuration further indicates which HARQ transmissions in a set of HARQ transmissions that are used for the channel report (CHR).

10. A network access node (300) for a communication system (500), the network access node (300) being configured to transmit a set of PDSCH repetitions of a transport block transmission to a client device (100); receive a channel report (CHR) for the transport block transmission from the client device (100), the channel report (CHR) being determined based on a channel report configuration, wherein the channel report configuration indicates which PDSCH repetitions in the set of PDSCH repetitions that are used by the client device (100) for determining the channel report (CHR); and determine one or more transmission parameters for a subsequent transmission of a set of PDSCH repetitions based on the channel report (CHR).

11. The network access node (300) according to claim 10, wherein the channel report configuration indicates that only the first PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report (CHR); or only the last PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report (CHR).

12. The network access node (300) according to claim 10, wherein the channel report configuration indicates that the n-th PDSCH repetition in the set of PDSCH repetitions is used for determining the channel report (CHR).

13. The network access node (300) according to claim 12, wherein the channel report configuration further indicates that at least one previous PDSCH repetition in the set of PDSCH

30 repetitions is used together with the n-th PDSCH repetition for determining the channel report (CHR).

14. The network access node (300) according to any one of claims 10 to 13, configured to transmit a first control message (510) to the client device (100), the first control message (510) indicating the channel report configuration.

15. The network access node (300) according to any one of claims 10 to 13, configured to receive a second control message (520) from the client device (100), the second control message (520) indicating the channel report configuration.

16. The network access node (300) according to any one of claims 10 to 15, wherein the channel report configuration further indicates which HARQ transmissions in a set of HARQ transmissions that are used for the channel report (CHR).

17. A method (200) for a client device (100), the method (200) comprising: receiving (202) a set of physical downlink shared channel, PDSCH, repetitions of a transport block transmission from a network access node (300); determining (204) a channel report (CHR) for the transport block transmission based on a channel report configuration, wherein the channel report configuration indicates which PDSCH repetitions in the set of PDSCH repetitions that are used by the client device (100) for determining the channel report (CHR); and transmitting (206) the channel report (CHR) to the network access node (300).

18. A method (400) for a network access node (300), the method (400) comprising: transmitting (402) a set of PDSCH repetitions of a transport block transmission to a client device (100); receiving (404) a channel report (CHR) for the transport block transmission from the client device (100), the channel report (CHR) being determined based on a channel report configuration, wherein the channel report configuration indicates which PDSCH repetitions in the set of PDSCH repetitions that are used by the client device (100) for determining the channel report (CHR); and determining (406) one or more transmission parameters for a subsequent transmission of a set of PDSCH repetitions based on the channel report (CHR).

19. A device comprising: a processor, and a memory coupled to the processor and having processor-executable instructions stored thereon, which when executed by the processor, cause the processor to perform the method of claim 17 or 18.