Compressed pdcch reception feedback

Abstract

Systems, methods, apparatuses, and computer program products for compressed PDCCH reception feedback A method may include determining whether at least one downlink data transmission of a transport block is correctly received and generating a hybrid-ARQ codebook based on whether the at least one downlink data transmission of a transport block is correctly received. The method may also include determining PDCCH reception feedback information corresponding to each entry of the generated hybrid- ARQ codebook based on whether a downlink control transmission was correctly received corresponding to each entry of the generated hybrid-ARQ codebook and compressing the PDCCH reception feedback information. The method may also include transmitting, to a network entity, uplink control information comprising: the hybrid-ARQ codebook, and the compressed PDCCH reception feedback information.

Description

COMPRESSED PDCCH RECEPTION FEEDBACKCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of US provisional application No. 63 / 693,381 , filed September 11 , 2024. The content of which are hereby incorporated by reference in their entirety.TECHNICAL FIELD

[0002] The examples and non-limiting example embodiments relate generally to communications and, more particularly, to compressed PDCCH reception feedback.BACKGROUND

[0003] It is known for a communication device to gain access to a communication network through an access network node.SUMMARY

[0004] In general, exemplary embodiments of the present disclosure provide a solution for compressed PDCCH reception feedback.

[0005] In a first aspect, there is provided an apparatus. The apparatus may include at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine whether at least one downlink data transmission of a transport block is correctly received; generate a hybrid-ARQ codebook based on whether the at least one downlink data transmission of a transport block is correctly received; determine PDCCH reception feedback information corresponding to each entry of the generated hybrid-ARQ codebook based on whether a downlink control transmission was correctly received corresponding to each entry of the generated hybrid- ARQ codebook; compress the PDCCH reception feedback information based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received; and transmit, to a network entity, uplink control information comprising: the hybrid-ARQ codebook, and the compressed PDCCH reception feedback information.

[0006] In a second aspect, there is provided an apparatus. The apparatus may include at least one processor; and at least one memory storing instructions that, when executed by the at least one processor,cause the apparatus at least to: transmit, to the user equipment, data with at least one downlink data transmission of a transport block; transmit, to the user equipment, at least one downlink control transmission; and receive, from the user equipment, uplink control information comprising: a hybrid-ARQ codebook, and compressed PDCCH reception feedback information; wherein the compressed PDCCH reception feedback information received from the user equipment is based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received .

[0007] In a third aspect, there is provided a method. The method may include determining whether at least one downlink data transmission of a transport block is correctly received; generating a hybrid-ARQ codebook based on whether the at least one downlink data transmission of a transport block is correctly received; determining PDCCH reception feedback information corresponding to each entry of the generated hybrid-ARQ codebook based on whether a downlink control transmission was correctly received corresponding to each entry of the generated hybrid-ARQ codebook; compressing the PDCCH reception feedback information based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received; and transmitting, to a network entity, uplink control information comprising: the hybrid-ARQ codebook, and the compressed PDCCH reception feedback information.

[0008] In a fourth aspect, there is provided a method. The method may include transmitting, to the user equipment, data with at least one downlink data transmission of a transport block; transmitting, to the user equipment, at least one downlink control transmission; and receiving, from the user equipment, uplink control information comprising: a hybrid-ARQ codebook, and compressed PDCCH reception feedback information; wherein the compressed PDCCH reception feedback information received from the user equipment is based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is notcorrectly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The foregoing aspects and other features are explained in the following description, taken in connection with the accompanying drawings.

[0010] FIG. 1 is a block diagram of one possible and non-limiting system in which the example embodiments may be practiced.

[0011] FIG. 2 shows an example of HARQ-ACK and PDCCH reception feedback without compression.

[0012] FIG. 3 shows an example of PDSCH PDCCH reception feedback bundling.

[0013] FIG. 4 shows an example of PDCCH reception feedback mechanism option 2 for a Type 1 HARQ-ACK codebook.

[0014] FIG. 5 shows an example of PDCCH reception feedback mechanism option 2 for a Type 2 HARQ- ACK codebook.

[0015] FIG. 6 shows an example flow chart of an example implementation, based on the methods described herein.

[0016] FIG. 7 is an example apparatus configured to implement the examples described herein.

[0017] FIG. 8 shows a representation of an example of non-volatile memory media used to store instructions that implement the examples described herein.

[0018] FIG. 9 is an example method, based on the examples described herein.

[0019] FIG. 10 is an example method, based on the examples described herein.DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0020] Turning to FIG. 1 , this figure shows a block diagram of one possible and non-limiting example in which the examples may be practiced. A user equipment (UE) 110, radio access network (RAN) node 170, and network element(s) 190 are illustrated. In the example of FIG. 1 , the user equipment (UE) 110 is in wireless communication with a wireless network 100. A UE is a wireless device that can access the wireless network 100. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected through one or more buses 127. Each of the one or more transceivers 130 includes a receiver, Rx, 132 and a transmitter, Tx, 133. The one or more buses 127 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, and the like. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. The UE 110 includes a module 140, comprising oneof or both parts 140-1 and / or 140-2, which may be implemented in a number of ways. The module 140 may be implemented in hardware as module 140-1 , such as being implemented as part of the one or more processors 120. The module 140-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the module 140 may be implemented as module 140-2, which is implemented as computer program code 123 and is executed by the one or more processors 120. For instance, the one or more memories 125 and the computer program code 123 may be configured to, with the one or more processors 120, cause the user equipment 110 to perform one or more of the operations as described herein. The UE 110 communicates with RAN node 170 via a wireless link 111.

[0021] The RAN node 170 in this example is a base station that provides access for wireless devices such as the UE 110 to the wireless network 100. The RAN node 170 may be, for example, a base station for 5G, also called New Radio (NR). In 5G, the RAN node 170 may be a NG-RAN node, which is defined as either a gNB or an ng-eNB. A gNB is a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface (such as connection 131) to a 5GC (such as, for example, the network element(s) 190). The ng-eNB is a node providing E-UTRA user plane and control plane protocol terminations towards the UE, and connected via the NG interface (such as connection 131) to the 5GC. The NG-RAN node may include multiple gNBs, which may also include a central unit (CU) (gNB-CU) 196 and distributed unit(s) (DUs) (gNB-DUs), of which DU 195 is shown. Note that the DU 195 may include or be coupled to and control a radio unit (RU). The gNB-CU 196 is a logical node hosting radio resource control (RRC), SDAP and PDCP protocols of the gNB or RRC and PDCP protocols of the en-gNB that control the operation of one or more gNB-DUs. The gNB-CU 196 terminates the F1 interface connected with the gNB-DU 195. The F1 interface is illustrated as reference 198, although reference 198 also illustrates a link between remote elements of the RAN node 170 and centralized elements of the RAN node 170, such as between the gNB-CU 196 and the gNB-DU 195. The gNB-DU 195 is a logical node hosting RLC, MAC and PHY layers of the gNB or en-gNB, and its operation is partly controlled by gNB-CU 196. One gNB-CU 196 supports one or multiple cells. One cell may be supported with one gNB-DU 195, or one cell may be supported / shared with multiple DUs under RAN sharing. The gNB-DU 195 terminates the F1 interface 198 connected with the gNB-CU 196. Note that the DU 195 is considered to include the transceiver 160, e.g., as part of a RU, but some examples of this may have the transceiver 160 as part of a separate RU, e.g., under control of and connected to the DU 195. The RAN node 170 may also be an eNB (evolved NodeB) base station, for LTE (long term evolution), or any other suitable base station or node.

[0022] The RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N / W l / F(s)) 161 , and one or more transceivers 160 interconnected through oneor more buses 157. Each of the one or more transceivers 160 includes a receiver, Rx, 162 and a transmitter, Tx, 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The CU 196 may include the processor(s) 152, one or more memories 155, and network interfaces 161. Note that the DU 195 may also contain its own memory / memories and processor(s), and / or other hardware, but these are not shown.

[0023] The RAN node 170 includes a module 150, comprising one of or both parts 150-1 and / or 150-2, which may be implemented in a number of ways. The module 150 may be implemented in hardware as module 150-1 , such as being implemented as part of the one or more processors 152. The module 150-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the module 150 may be implemented as module 150-2, which is implemented as computer program code 153 and is executed by the one or more processors 152. For instance, the one or more memories 155 and the computer program code 153 are configured to, with the one or more processors 152, cause the RAN node 170 to perform one or more of the operations as described herein. Note that the functionality of the module 150 may be distributed, such as being distributed between the DU 195 and the CU 196, or be implemented solely in the DU 195.

[0024] The one or more network interfaces 161 communicate over a network such as via the links 176 and 131. Two or more gNBs 170 may communicate using, e.g., link 176. The link 176 may be wired or wireless or both and may implement, for example, an Xn interface for 5G, an X2 interface for LTE, or other suitable interface for other standards.

[0025] The one or more buses 157 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, wireless channels, and the like. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE or a distributed unit (DU) 195 for gNB implementation for 5G, with the other elements of the RAN node 170 possibly being physically in a different location from the RRH / DU 195, and the one or more buses 157 could be implemented in part as, for example, fiber optic cable or other suitable network connection to connect the other elements (e.g., a central unit (CU), gNB-CU 196) of the RAN node 170 to the RRH / DU 195. Reference 198 also indicates those suitable network link(s).

[0026] A RAN node / gNB can comprise one or more TRPs to which the methods described herein may be applied. FIG. 1 shows that the RAN node 170 comprises TRP 51 and TRP 52, in addition to the TRP represented by transceiver 160. Similar to transceiver 160, TRP 51 and TRP 52 may each include a transmitter and a receiver. The RAN node 170 may host or comprise other TRPs not shown in FIG. 1 .

[0027] A relay node in NR is called an integrated access and backhaul node. A mobile termination part of the IAB node facilitates the backhaul (parent link) connection. In other words, the mobile termination partcomprises the functionality which carries UE functionalities. The distributed unit part of the IAB node facilitates the so called access link (child link) connections (i.e. for access link UEs, and backhaul for other IAB nodes, in the case of multi-hop IAB). In other words, the distributed unit part is responsible for certain base station functionalities. The IAB scenario may follow the so called split architecture, where the central unit hosts the higher layer protocols to the UE and terminates the control plane and user plane interfaces to the 5G core network.

[0028] It is noted that the description herein indicates that "cells” perform functions, but it should be clear that equipment which forms the cell may perform the functions. The cell makes up part of a base station. That is, there can be multiple cells per base station. For example, there could be three cells for a single carrier frequency and associated bandwidth, each cell covering one-third of a 360 degree area so that the single base station's coverage area covers an approximate oval or circle. Furthermore, each cell can correspond to a single carrier and a base station may use multiple carriers. So if there are three 120 degree cells per carrier and two carriers, then the base station has a total of 6 cells.

[0029] The wireless network 100 may include a network element or elements 190 that may include core network functionality, and which provides connectivity via a link or links 181 with a further network, such as a telephone network and / or a data communications network (e.g., the Internet). Such core network functionality for 5G may include location management functions (LMF(s)) and / or access and mobility management function(s) (AMF(S)) and / or user plane functions (UPF(s)) and / or session management function(s) (SMF(s)). Such core network functionality for LTE may include MME (mobility management entity) / SGW (serving gateway) functionality. Such core network functionality may include SON (self- organizing / optimizing network) functionality. These are merely example functions that may be supported by the network element(s) 190, and note that both 5G and LTE functions might be supported. The RAN node 170 is coupled via a link 131 to the network element 190. The link 131 may be implemented as, e.g., an NG interface for 5G, or an S1 interface for LTE, or other suitable interface for other standards. The network element 190 includes one or more processors 175, one or more memories 171 , and one or more network interfaces (N / W l / F(s)) 180, interconnected through one or more buses 185. The one or more memories 171 include computer program code 173. Computer program code 173 may include SON and / or MRO functionality 172.

[0030] The wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single, softwarebased administrative entity, or a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as either external, combining many networks, or parts of networks, into a virtual unit, or internal, providing network-like functionality to software containers on a single system. Note that the virtualized entities that result fromthe network virtualization are still implemented, at some level, using hardware such as processors 152 or 175 and memories 155 and 171 , and also such virtualized entities create technical effects.

[0031] The computer readable memories 125, 155, and 171 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, non-transitory memory, transitory memory, fixed memory and removable memory. The computer readable memories 125, 155, and 171 may be means for performing storage functions. The processors 120, 152, and 175 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multi-core processor architecture, as non-limiting examples. The processors 120, 152, and 175 may be means for performing functions, such as controlling the UE 110, RAN node 170, network element(s) 190, and other functions as described herein.

[0032] In general, the various example embodiments of the user equipment 110 can include, but are not limited to, cellular telephones such as smart phones, tablets, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback devices having wireless communication capabilities, internet appliances including those permitting wireless internet access and browsing, tablets with wireless communication capabilities, head mounted displays such as those that implement virtual / augmented / mixed reality, as well as portable units or terminals that incorporate combinations of such functions. The UE 110 can also be a vehicle such as a car, or a UE mounted in a vehicle, a UAV such as e.g. a drone, or a UE mounted in a UAV. The user equipment 110 may be a terminal device, such as mobile phone, mobile device, sensor device etc., the terminal device being a device used by the user or not used by the user.

[0033] UE 110, RAN node 170, and / or network element(s) 190, (and associated memories, computer program code and modules) may be configured to implement (e.g. in part) the methods described herein. Thus, computer program code 123, module 140-1 , module 140-2, and other elements / features shown in FIG. 1 of UE 110 may implement user equipment related aspects of the examples described herein. Similarly, computer program code 153, module 150-1 , module 150-2, and other elements / features shown in FIG. 1 of RAN node 170 may implement gNB / TRP related aspects of the examples described herein. Computer program code 173 and other elements / features shown in FIG. 1 of network element(s) 190 may be configured to implement network element related aspects of the examples described herein.

[0034] Having thus introduced a suitable but non-limiting technical context for the practice of theexample embodiments, the example embodiments are now described with greater specificity.

[0035] The examples described herein relate to current and especially future radio standards, such as 6G and beyond. More specifically, the examples described herein relate to HARQ feedback and coping with missed detection of PDCCH DL assignments.

[0036] In addition to HARQ-ACK feedback, where the UE reports either ACK (when a DL PDSCH transmission has been received correctly) and NACK (PDSCH transmission has not been received correctly), it is also beneficial for the base station to know whether the UE has received correctly the DL assignment that scheduled the PDSCH, or not. This information is denoted as PDCCH reception feedback information. The benefits of such information are two-fold (1-2):

[0037] 1) If the network knows that the UE has missed the PDCCH scheduling PDSCH, it is also aware that the UE cannot combine the previous PDSCH transmission with PDSCH retransmissions to improve the decoding reliability of the data. The network can make use of this knowledge to e.g. choose a more conservative link adaptation parameters (e.g.. modulation and coding scheme) to improve the reliability of the data transmission in case the previous PDSCH was not received by the UE.

[0038] 2) Knowledge of a PDCCH reception failure can also assist the network in adjusting the downlink control channel (PDCCH) link adaptation for the upcoming data transmissions, e.g. by choosing a higher aggregation level (e.g. lower code rate) for the upcoming PDCCH transmissions.

[0039] In other words, PDCCH reception feedback would allow the network to distinguish whether the unsuccessful reception of a DL PDSCH transmission was due to a failure of PDCCH reception or PDSCH decoding.

[0040] Based on the existing PDSCH HARQ-ACK feedback procedure of 5G / NR, the gNB is not able to distinguish between the cases of (i) the UE did not decode the DL assignment scheduling a PDSCH and (ii) the UE correctly received the PDCCH DL assignment, but was not able to decode the scheduled PDSCH correctly (referring to 1 and 2 immediately below):

[0041] 1) For the (semi-static) Type 1 HARQ-ACK Codebook (CB), in case the HARQ-ACK of more than one scheduled PDSCH is to be mapped to the HARQ-ACK CB, the UE just reports ‘NACK’. Therefore, the gNB is not able to distinguish between these two cases. For the (semi-static) Type 1 HARQ-ACK Codebook (CB), in case only HARQ-ACK of one scheduled PDSCH is to be mapped to the HARQ-ACK CB, when the UE misses the DL assignment it does not report any HARQ-ACK for that HARQ-ACK reporting instance. This could be detected at the gNB as the UE would not correspondingly transmit PUCCH with HARQ-ACK, or the Type 1 HARQ-ACK CB would not be mapped on a PUSCH overlapping with the HARQ-ACK reporting instance.

[0042] For the (dynamic) Type 2 HARQ-ACK Codebook, in case the HARQ-ACK of more than one scheduled PDSCH is to be mapped to the HARQ-ACK CB, the UE is aware due to the C-DAI and / or T-DAIsignaling that it missed a DL assignment scheduling PDSCH, but just reports ‘NACK’. Therefore, the gNB is not able to distinguish between these two cases. For the (dynamic) Type 2 HARQ-ACK Codebook, in case only HARQ-ACK of one scheduled PDSCH is to be mapped to the HARQ-ACK CB, in case the UE missed the DL assignment it does not report any HARQ-ACK for that HARQ-ACK reporting instance. This could be detected at the gNB as the UE would not correspondingly transmit PUCCH with HARQ-ACK. But in case the UE would transmit a PUSCH overlapping with the HARQ-ACK reporting instance, UE would become aware of a missed DL assignment scheduling PDSCH due to UL-DAI signaling in the UL grants scheduling the PUSCH. However, the gNB could not identify the UE missing the DL assignment as the HARQ-ACK information would only contain ‘NACK’.

[0043] To circumvent these shortcomings, PDCCH reception feedback may be considered in addition to simple ACK / NACK feedback consisting of in total 3 states: 1) ACK to indicate PDSCH decoding pass, 2) NACK to indicate PDCCH reception but PDSCH decoding failure, and 3) PDCCH reception feedback to indicate downlink control not received (e.g. downlink control failure / miss or no PDCCH was transmitted). This approach is applicable only to Type 2 CB, where the UE can identify the PDCCH failure / miss based on DAI.

[0044] PDCCH link quality reporting may also be implemented. However, the reporting is separate from the actual HARQ feedback and serves only detection of the PDCCH link quality problem and link adaptation.

[0045] While PDCCH reception feedback has clear benefits, as discussed in the previous sections, it also comes with a drawback: The payload size of the HARQ-ACK feedback consisting of three states increases the feedback payload considerably, which in turn reduces the reliability of decoding of the feedback transmitted in the uplink on PUCCH or PUSCH. Assuming the feedback for S TBs in the spatial domain (according to the rank, for NR S=1 for up to 4 layers and S=2 for >4 spatial layers), T TBs in the time domain, and F TBs in frequency (or carrier / serving DL cell) domain, the number of additional PDCCH reception feedback bits becomes S*T*F. That is, the amount of HARQ feedback would be doubled, which inevitably reduces the uplink coverage of the feedback, and / or increase the uplink overhead (the amount of PUCCH / PUSCH resources that need to be reserved for HARQ-ACK feedback transmissions).

[0046] As a simple example, consider the scenario shown in FIG. 2, where HARQ feedback is provided for two time instances (TTIs, 7=2) TT 1 and TT2, and four component carriers (CCs, F=4) CC1 , CC2, CC3, and CC4. Assuming S=1 , altogether 8 PDSCH Transport Blocks (TBs) are transmitted by the network to the UE and HARQ-ACK feedback 202 consisting of two states (ACK / NACK) requires 8 bits. If PDCCH reception feedback (denoted as ‘D’) 204 is additionally embedded to the feedback report, the number of required bits doubles, making decoding of the feedback transmitted on PUCCH / PUSCH significantly less reliable and / or resource consuming.

[0047] Described herein are methods for compressing the PDCCH reception feedback 204, such that the key benefits of three-state HARQ / PDCCH reception feedback are preserved while keeping the additional UL signaling overhead at a reasonable level.

[0048] The idea is to combine or otherwise compress PDCCH reception feedback for two or more transport blocks such that the number of PDCCH reception feedback bits can be reduced or otherwise limit / compress the size of PDCCH reception feedback. Two mechanisms for feedback combining are described herein: using logical AND (or logical OR) operation (aka. Bundling) or reporting a count of received or missed PDCCHs for a set of TBs, depending on the HARQ-ACK codebook type.

[0049] In an example, the following definition (Definition 1) for the PDCCH reception feedback (FB) is assumed:

[0050] That is, when bundling PDCCH reception feedback with logical AND, if all corresponding PDCCHs are not received, the value of the bundled PDCCH reception feedback bit is 1 ; otherwise, if at least one PDCCH is received correctly, the value of PDCCH reception feedback bit is 0.

[0051] An alternative definition (Definition 2) is as below:

[0052] There, assuming logical AND operation, the PDCCH reception feedback specifically indicates the case where at least one PDCCH is received correctly, but the reception of the corresponding PDSCH is not successful.

[0053] For the first table, the mapping could be defined in the opposite way as well, i.e. PDCCH reception feedback bits in the tables above are switched from 0 to 1 and 1 to 0. In that case, logical OR operation may be used instead of AND.

[0054] Furthermore, the following parameters are defined:L = the number of PDSCH candidates considered in the bundling (corresponds to ACK / NACK bits after spatial bundling)N = the number of PDCCH reception feedback blocks (i.e. DRX bits) i.e. the number of bundling windowsK = the number of PDSCHs or PDSCH candidates in each PDCCH reception feedback block, for which PDCCH reception feedback is bundled to one bit

[0055] For Mechanism / Option 1 PDCCH reception feedback bundling, the following options are considered:

[0056] As in normal operation, ACK / NACK feedback is provided according to the configuration (for each TB, or possibly with some ACK / NACK bundling in spatial / frequency / time domains). In case ACK / NACK bundling is applied for some of the TBs in ACK / NACK feedback, PDCCH reception feedback bundling can be applied for the same bundled TBs as well.

[0057] For each TB, the UE determines PDCCH reception feedback according to the tables shown above. In one alternative, the PDCCH reception feedback (FB) is determined only for TBs for which NACK is reported and, correspondingly,

[0058] Bundling is applied for the PDCCH reception feedback corresponding to different TBs as follows (as a combination of one or more of the following), see FIG. 3.

[0059] The PDCCH reception feedback for the different TBs of a SU-MIMO transmission with multiple TBs is bundled (not shown in the figure), since they are scheduled by the same PDCCH anyway. This bundling is performed first, if combined with any other bundling mechanism.

[0060] PDCCH reception feedback for TBs on different component carriers (CCs) and / or slots / TTIs may be bundled. Alt 1 shows the option with PDCCH reception feedback time domain bundling, where feedback corresponding to different PDSCH transport blocks transmitted on the same carrier (e.g. TB1 and TB5 for CC1), but in different time instances, are bundled. Alt 2 illustrates an option, where bundling is applied for PDCCH reception feedback in both time and frequency (CC) domains. Alt. 3 illustrates an option, where there is fixed number N of PDCCH reception feedback bits allocated for feedback (e.g. N=4 bits in case of FIG. 3) and PDCCH reception feedback is provided for N first TBs with "NACK”. The order of N first TBs may be defined e.g. in frequency first, time second manner.

[0061] For Alt.1 and 2, the PDCCH reception feedback bundling may be performed across TBs for which either ACK or NACK is reported or, alternatively, only across TBs for which NACK is reported.

[0062] All alternatives 1 , 2, and 3 are applicable with all HARQ-ACK Codebook types and are particularly suited for the Type 2 HARQ-ACK codebook. In case of Type 1 HARQ-ACK codebook, if PDCCH reception feedback bundling is performed across TBs for which either ACK or NACK is reported, the PDCCH reception feedback definition option 2 (Definition 2) with logical AND is well suited, i.e. the UE reports 0 ifat least one PDCCH is received correctly but the reception of the corresponding PDSCH is not successful.

[0063] The use of bundling results in coarser granularity for PDCCH reception feedback, i.e. the gNB can no longer be fully certain for which of the TBs with joint PDCCH reception feedback the decoding of the PDCCH has failed. However, this is not an issue, since the PDCCH decoding errors on e.g. adjacent slots / TTIs are expected to be correlated. Furthermore, for the PDCCH link adaptation it suffices to know that at least one of the PDCCH receptions was not successful, so that gNB may select a more robust coding (e.g. higher aggregation level) for the next PDCCH transmissions. The same applies also for PDSCH retransmissions: gNB can choose a more conservative link adaptation parameters (e.g.. MCS) and / or self-decodable redundancy version, e.g. RVO for the set of TBs / PDSCHs for which a joint PDCCH reception feedback was indicated, to enable successful PDSCH reception of the retransmission.

[0064] In FIG. 3, b1 .. b16 denote uplink control information bits (collectively UCI bits 302), where b1 ...b8 are the ACK / NACK bits corresponding to transport blocks 1... 8, and b9 ... b16 are the PDCCH reception feedback bits. Compared to providing PDCCH reception feedback information for each TB of FIG. 2 requiring 8 PDCCH reception feedback bits, the required number of bits for PDCCH reception feedback is reduced to 4 bits for Alt. 1 and Alt. 3 (where PDCCH reception feedback is provided using bits b9, b10, b11 , and b12), and to 2 bits for Alt. 2 (where PDCCH reception feedback is provided using bits b9 and b10).

[0065] Mechanism / Option 2: Combined PDCCH reception feedback with a count of received or missed PDCCHs

[0066] The mechanism is specific for each HARQ codebook (CB) type:

[0067] In case of Type 1 HARQ-ACK CB, the UE (e.g. UE 110) does not know when it has missed a PDCCH. Type 1 HARQ-ACK CB comprises of ACK / NACK feedback for PDSCH candidates. As used within this description, a PDSCH candidate refers to a set of time / frequency resources which may or may not contain a PDSCH scheduled for the UE and have its ACK / NACK transmitted in the Type 1 HARQ-ACK CB in question. For example, a such set of time / frequency resources may be a time slot on a carrier, DL serving cell, or active BWP (the set covers all RBs of the carrier / cell / BWP as UE can be scheduled only one PDSCH at a time on each carrier / cell / BWP). UE reports NACK in Type 1 HARQ-ACK CB for a PDSCH candidate for which UE did not receive any corresponding DCI.

[0068] Based on the HARQ-ACK CB content, only those PDSCH candidates with NACK-only feedback are considered in the next step (i.e. if ACK is reported for any TB or CBG, the PDSCH is not considered). These NACKs-only PDSCH candidates are divided into N about equal sized blocks, where N is predetermined or configured. Alternatively, the number of blocks N may be determined based on the size of Type 1 HARQ-ACK codebook and maximum size K of a block, where K is predetermined or configured. Let's say that the CB covers L reported PDSCH candidates, then N = eL / Ku. For each block, the numberof PDSCHs for which DCI was received but TB decoding failed is counted and reported (in a field of size elog2(K)u bits: e.g. 0, 1 , 2, or 3 or more). In total, N*elog2(K)u bits are required for the PDCCH reception feedback. In a variant, the field size for the PDCCH reception feedback is predetermined or configured, say of R bits. In case that the number of PDSCHs in the block for which DCI was received but TB decoding failed is larger than the maximum value of the PDCCH reception feedback field, 2R-1 , UE reports the maximum value on the PDCCH reception feedback field.

[0069] In another variant, the division to N blocks is done for all PDSCH candidates irrespective if ACKs or NACKs are reported.

[0070] FIG. 4 shows an example of Mechanism / Option 2 for Type 1 CB. FIG. 4 illustrates 6 PDSCH candidates. There are K=4 NACK-only PDSCH candidates (#2, #3, #5, and #6). For PDSCH candidates #5 and #6, DCI is received correctly (referring to the row given with item 402) and both PDSCH transport blocks are not received (i.e. two NACKs, referring to the row given with item 404, where an A / N value of ‘A’ corresponds to an ACK, and an A / N value of ‘N’ corresponds to a NACK). Hence, the count is incremented for both, resulting in a reported count =2.

[0071] When gNB receives the ACK / NACK feedback shown above together with the count of received PDCCHs per CB (i.e. 2 in FIG. 4): gNB knows that the scheduled PDSCHs map to PDSCH candidates 1 ,3,4,5, and 6, and ignores feedback for PDSCH2 as this PDSCH has not been transmitted. PDSCH1 and PDSCH4 report at least one ACK, meaning that PDSCH3, PDSCH5, and PDSCH6 should be in the counted number of PDCCHs. As the reported count is 2, gNB knows that DCI is missed for one of PDSCH3, PDSCH5, and PDSCH6. Based on this, gNB may schedule PDSCH re-transmission with redundancy version 0 for PDSCH3, PDSCH5, and PDSCH6 and, possibly, increase the PDCCH aggregation level used for scheduling of the UE.

[0072] In case of the Type 2 HARQ-ACK CB, most of the entries may be ACKs on average and UE knows when it has missed a PDCCH. From the CB contents, only those PDSCHs with NACK-only feedback are considered in the next step (i.e. if ACK is reported to any TB or code block group (CBG) of TB on the PDSCH scheduled by a PDCCH, the PDSCH is not considered). These NACKs-only PDSCHs are divided into N about equal size blocks, where N is predetermined or configured. N may be also dependent on the size of reported HARQ-ACK codebook, e.g. N is incremented by one for each K reported ACK / NACK by having K predetermined or configured. In the latter case, for a Type 2 HARQ-ACK codebook containing ACK / NACKs for L reported PDSCHs, N = eL / Ku. For each block, the number of PDSCHs for which PDCCH DCI was not received are counted and reported (using a size field of elog2(K)u bits: e.g. 0, 1 , 2, or 3 or more). In total, N*elog2(K)u bits are required for the PDCCH reception feedback. In another variant, the division to N blocks is done for all PDSCHs irrespective if ACKs or NACKs are reported.

[0073] FIG. 5 shows an example of Mechanism / Option 2 for Type 2 CB. The figure illustrates 6 PDSCHcandidates. There are K=4 NACK-only PDSCH candidates (#2, #3, #5, and #6). For PDSCH candidates 2 and 3, DCI is NOT received correctly (referring to item 502) and both PDSCH transport blocks are not received (i.e. two NACKs, referring to item 504). Hence, the count is incremented for both, resulting in a reported count =2.

[0074] UE reporting PDCCH reception feedback information can help gNB in the PDCCH link adaptation, yielding in more efficient use of PDCCH resources while maintaining sufficiently reliable PDCCH reception. It helps gNB also in the PDSCH retransmission link adaptation: gNB can use more aggressive link adaptation when it knows that UE has received earlier PDSCH scheduling DCI and resort to more conservative link adaptation when there is indication that UE may have missed the previous scheduling DCI.

[0075] However, PDCCH reception reporting for each PDSCH separately leads to too large increase in the feedback, given that the PDCCH decoding failure is rather infrequent occasion.

[0076] Favorable compromise between increased UCI size and improved PDCCH and PDSCH link adaptation can be achieved with solutions to compress or bundle the PDCCH reception feedback information. The increase in the UCI size can be kept relatively small, but when PDCCH reception feedback is indicated, gNB needs to apply more conservative link adaptation only for a rather small number of PDSCHs, associated to the same PDCCH reception feedback information.

[0077] When the network determines based on the received PDCCH reception feedback that a DCI (i.e. a PDCCH) is missed, the NW takes that into account when scheduling re-transmission for all those PDSCHs.

[0078] The operation of the embodiments described herein can be represented also in terms of a signaling flow chart between the network (e.g. base station 170) and UE 110 of FIG. 6.

[0079] In step 1 , the gNB signals information related to PDCCH reception feedback reporting to the UE. This signaling may be based on RRC, MAC CE or PHY signaling.

[0080] For Mechanism / Option 1 , this may as an example include the bundling window size for Alt. 1 and Alt. 2 (i.e. how PDSCHs are bundled into per reported PDCCH reception feedback bit). The number of required PDCCH reception feedback bits to be appended / concatenated to the Type 2 HARQ-ACK CB would then be determined based on the number of required bundling windows and the bundling window size. Alternatively for Alt. 1 and Alt. 2, the UE may be indicated a number of bits for the PDCCH reception reporting which would then define the required bundling size window based on the HARQ-ACK to be reported. For Alt. 3, the number N for the reporting of the first N TBs with "NACK”. Optionally if more than one of the Option 1 alternatives are supported, which of the 3 alternatives is to be used (i.e. time-domain bundling, time-carrier domain bundling or ‘first N' reporting).

[0081] For Mechanism / Option 2, this may for example include the number of groups N of PDSCHcandidates (for Type 1 / Type 2 HARQ-ACK CB). Or alternatively, the maximum number of PDSCH candidates per group K (for Type 1 / Type 2 HARQ-ACK CB).

[0082] In step 2, the gNB schedules the UE with PDSCH reception(s). Thereby, the PDCCH DCI scheduling PDSCH(s) as well as the PDSCH(s) are transmitted by the gNB to the UE.

[0083] In step 3, the UE performs DL control decoding, and for correctly decoded DCIs scheduling a PDSCH (i.e. correctly decoded DL assignment), tries to decode the PDSCHs.

[0084] In step 4, the UE, based on the reception of DL assignments and correctly decoded PDSCHs, generates the applicable HARQ-ACK codebook.

[0085] In step 5, the UE determines PDCCH reception feedback information based on (i) the signaling of step 1 , (ii) the correctly received DL assignments (i.e. DCIs scheduling PDSCH) of step 3 and (iii) the HARQ-ACK of step 4.

[0086] For Method / Option 1 , this includes for Alt. 1 and Alt. 2, as described previously the UE determines the PDCCH reception feedback bits based on the bundling operation. For Method / Option 1 , this includes for Alt. 3, the UE determines the N HARQ-ACK bits for PDCCH reception feedback for the first N HARQ-ACK CB entries with reported ‘NACK’.

[0087] For Method / Option 2, as described in detail previously this includes for Type 1 HARQ-ACK CB (i-iii): (I) determine the N groups of PDSCH candidates with maximum size of K for the HARQ-ACK CB, for which ‘NACK’ is reported based the Type 1 HARQ-ACK CB of step4, (ii) for each of the N groups, count the number of correctly received DL assignments (DCIs scheduling PDSCH), (iii) generate the PDCCH reception feedback information by mapping the counted value using log2(K)l for each of the N groups (i.e. in total N log2(K)~| bits PDCCH reception feedback information are generated).

[0088] For Method / Option 2, as described in detail previously this includes for Type 2 HARQ-ACK CB, (I) determine the N groups of PDSCH candidates as for the Type 1 above, (ii) for each of the N groups, count the number of PDSCH candidates for which the DL assignments (DCI scheduling PDSCH) was not received, (iii) generate the PDCCH reception feedback information as for Type 1 HARQ-ACK CB above.

[0089] In step 6, the UE generates the PDSCH related UL control information by combining (at least) the determined HARQ-ACK CB of step 4 with the PDCCH reception feedback information of step 5. In one preferred implementation, the PDCCH reception feedback bits of step 5 are appended (concatenated) to the HARQ-ACK CB of step 5. Alternative implementations of combining HARQ-ACK CB of step 4 and the PDCCH reception feedback information of step 5 are of course possible. For UCI multiplexing, the combined information of HARQ-ACK and PDCCH reception feedback is handled as HARQ-ACK information in terms of HARQ-ACK multiplexing on PUCCH and / or PUSCH.

[0090] In step 7, the UE transmits the uplink control information to the gNB. As mentioned in step 6, in terms of UCI multiplexing, the same procedures as for HARQ-ACK mapping on PUCCH / PUSCH areapplied to the combined feedback information of HARQ-ACK and PDCCH reception feedback. The UCI (including the HARQ-ACK and PDCCH reception feedback information) may be transmitted by PUCCH or PUSCH to the gNB.

[0091] In step 8, the gNB receives the UL control information transmitted by the UE of step 7. Based on the included PDCCH reception feedback information included in the UCI received on PUCCH or PUSCH, the gNB (as described previously) is able to adjust the PDCCH link adaptation (e.g. to further prevent missed DL assignments) and / or take the HARQ-ACK and PDCCH reception feedback information into account for PDSCH re-transmission adaption depending on if the DL assignment as been received or not.

[0092] Advantages and technical effects of the examples described herein include providing the network information of whether an error in PDSCH data transmission was due to failure in PDCCH or PDSCH reception. This allows the network to adjust link adaptation parameters for PDCCH or PDSCH, depending on which one is the bottle neck. Compared to prior solutions, additional overhead due to PDCCH reception feedback is reduced significantly, due to the compression methods described herein. The loss in feedback granularity is not expected to have a significant impact on the operation, since the PDCCH / PDSCH decoding errors across the different TBs that are bundled are expected to be correlated. The examples described herein can be applied with all three HARQ feedback codebook types from 5G NR.

[0093] The examples described herein may be applicable to 3GPP, and 6G and beyond.

[0094] FIG. 7 is an example apparatus 700, which may be implemented in hardware, configured to implement the examples described herein. The apparatus 700 comprises at least one processor 702 (e.g. an FPGA and / or CPU), one or more memories 704 including computer program code 705, the computer program code 705 having instructions to carry out the methods described herein, wherein the at least one memory 704 and the computer program code 705 are configured to, with the at least one processor 702, cause the apparatus 700 to implement circuitry, a process, component, module, or function (implemented with control module 706) to implement the examples described herein. The one or more memories 704 may include a non-transitory memory, a transitory memory, a volatile memory (e.g. RAM), or a non-volatile memory (e.g. ROM).

[0095] Compressed PDCCH reception feedback 730 implements the examples described herein related to compressed PDCCH reception feedback.

[0096] The apparatus 700 includes a display and / or I / O interface 708, which includes user interface (Ul) circuitry and elements, that may be used to display aspects or a status of the methods described herein (e.g., as one of the methods is being performed or at a subsequent time), or to receive input from a user such as with using a keypad, camera, touchscreen, touch area, microphone, biometric recognition, one or more sensors, etc. The apparatus 700 includes one or more communication e.g. network (N / W) interfaces(I / F(s)) 710. The communication l / F(s) 710 may be wired and / or wireless and communicate over the Internet / other network(s) via any communication technique including via one or more links 724. The link(s) 724 may be the link(s) 131 and / or 176 from FIG. 1. The link(s) 131 and / or 176 from FIG. 1 may also be implemented using transceiver(s) 716 and corresponding wireless link(s) 726. The communication l / F(s) 710 may comprise one or more transmitters or one or more receivers.

[0097] The transceiver 716 comprises one or more transmitters 718 and one or more receivers 720. The transceiver 716 and / or communication l / F(s) 710 may comprise standard well-known components such as an amplifier, filter, frequency-converter, (de)modulator, and encoder / decoder circuitries and one or more antennas, such as antennas 714 used for communication over wireless link 726.

[0098] The control module 706 of the apparatus 700 comprises one of or both parts 706-1 and / or 706- 2, which may be implemented in a number of ways. The control module 706 may be implemented in hardware as control module 706-1 , such as being implemented as part of the one or more processors 702. The control module 706-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the control module 706 may be implemented as control module 706-2, which is implemented as computer program code (having corresponding instructions) 705 and is executed by the one or more processors 702. For instance, the one or more memories 704 store instructions that, when executed by the one or more processors 702, cause the apparatus 700 to perform one or more of the operations as described herein. Furthermore, the one or more processors 702, the one or more memories 704, and example algorithms (e.g., as flowcharts and / or signaling diagrams), encoded as instructions, programs, or code, are means for causing performance of the operations described herein.

[0099] The apparatus 700 to implement the functionality of control 706 may be UE 110, RAN node 170 (e.g. gNB), or network element(s) 190 (e.g. LMF 190). Thus, processor 702 may correspond to processor(s) 120, processor(s) 152 and / or processor(s) 175, memory 704 may correspond to one or more memories 125, one or more memories 155 and / or one or more memories 171 , computer program code 705 may correspond to computer program code 123, computer program code 153, and / or computer program code 173, control module 706 may correspond to module 140-1 , module 140-2, module 150-1 , and / or module 150-2, and communication l / F(s) 710 and / or transceiver 716 may correspond to transceiver 130, antenna(s) 128, transceiver 160, antenna(s) 158, N / W l / F(s) 161 , and / or N / W l / F(s) 180. Alternatively, apparatus 700 and its elements may not correspond to either of UE 110, RAN node 170, or network element(s) 190 and their respective elements, as apparatus 700 may be part of a self-organizing / optimizing network (SON) node or other node, such as a node in a cloud.

[0100] The apparatus 700 may also be distributed throughout the network (e.g. 100) including within and between apparatus 700 and any network element (such as a network control element (NCE) 190and / or the RAN node 170 and / or UE 110).

[0101] Interface 712 enables data communication and signaling between the various items of apparatus 700, as shown in FIG. 7. For example, the interface 712 may be one or more buses such as address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, and the like. Computer program code (e.g. instructions) 705, including control 706 may comprise object-oriented software configured to pass data or messages between objects within computer program code 705, or computer program code (e.g. instructions) 705, including control 706 may include functional, scripting, or procedural code. The apparatus 700 need not comprise each of the features mentioned, or may comprise other features as well. The various components of apparatus 700 may at least partially reside in a common housing 728, or a subset of the various components of apparatus 700 may at least partially be located in different housings, which different housings may include housing 728.

[0102] FIG. 8 shows a schematic representation of non-volatile memory media 800a (e.g. computer / compact disc (CD) or digital versatile disc (DVD)) and 800b (e.g. universal serial bus (USB) memory stick) and 800c (e.g. cloud storage for downloading instructions and / or parameters 802 or receiving emailed instructions and / or parameters 802) storing instructions and / or parameters 802 which when executed by a processor allows the processor to perform one or more of the steps of the methods described herein. Instructions and / or parameters 802 may represent a computer readable medium.

[0103] FIG. 9 is an example method 900 based on the examples described herein. At 910, the method includes determining whether at least one downlink data transmission of a transport block is correctly received. At 920, the method includes generating a hybrid-ARQ codebook based on whether the at least one downlink data transmission of a transport block is correctly received. At 930, the method includes determining PDCCH reception feedback information corresponding to each entry of the generated hybrid- ARQ codebook based on whether a downlink control transmission was correctly received corresponding to each entry of the generated hybrid-ARQ codebook. At 940, the method includes compressing the PDCCH reception feedback information based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received. At 950, the method includes transmitting, to a network entity, uplink control information comprising: the hybrid-ARQ codebook, and the compressed PDCCH reception feedback information. Method 900 may be performed with UE 110 or apparatus 700.

[0104] FIG. 10 is an example method 1000 based on the examples described herein. At 1010, the method includes transmitting, to the user equipment, data with at least one downlink data transmission of a transport block. At 1020, the method includes transmitting, to the user equipment, at least one downlink control transmission. At 1030, the method includes receiving, from the user equipment, uplink control information comprising: a hybrid-ARQ codebook, and compressed PDCCH reception feedback information. At 1040, the method includes wherein the compressed PDCCH reception feedback information received from the user equipment is based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received. Method 1000 may be performed with RAN node 170, one or more network elements 190, or apparatus 700.

[0105] The following examples are provided and described herein.

[0106] Example 1 . An apparatus including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine whether at least one downlink data transmission of a transport block is correctly received; generate a hybrid-ARQ codebook based on whether the at least one downlink data transmission of a transport block is correctly received; determine PDCCH reception feedback information corresponding to each entry of the generated hybrid-ARQ codebook based on whether a downlink control transmission was correctly received corresponding to each entry of the generated hybrid-ARQ codebook; compress the PDCCH reception feedback information based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received; and transmit, to a network entity, uplink control information comprising: the hybrid-ARQ codebook, and the compressed PDCCH reception feedback information.

[0107] Example 2. The apparatus of example 1 , wherein: the compressed PDCCH reception feedback information is transmitted for two or more downlink data transmissions of the at least one downlink data transmission with one bit, based on the logical bundling operation that is performed using a logical AND operation or a logical OR operation, and the logical bundling operation is performed with a first input and a second input, wherein the first input comprises whether or not the at least one downlink data transmissionof a transport block is correctly received, and wherein the second input comprises whether or not the at least one downlink control transmission is correctly received.

[0108] Example 3. The apparatus of example 2, wherein the two or more downlink data transmissions for which the compressed PDCCH feedback information is transmitted with one bit are in at least one or more of: a common time domain, or a common frequency domain, or a common spatial domain.

[0109] Example 4. The apparatus of any of examples 2 to 3, wherein the compressed PDCCH reception feedback information is transmitted using a number of bits corresponding to a number of one or more bundling windows, wherein a bundling window comprises a bundling window size that corresponds to a number of the two or more downlink data transmissions that are bundled into one bit.

[0110] Example 5. The apparatus of example 4, wherein the apparatus is further caused to: receive, from the network entity, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is transmitted based on the information related to compressed PDCCH reception reporting received from the network entity; wherein the information related to compressed PDCCH reception reporting received from the network entity comprises at least one or more of: the bundling window size, or the number of one or more bundling windows each comprising the bundling window size that corresponds to the number of the two or more downlink data transmissions that are bundled into one bit.

[0111] Example 6. The apparatus of example 1 , wherein the compressed PDCCH reception feedback information is transmitted to the network entity for up to a first number of transport blocks corresponding to the at least one downlink data transmission with a negative acknowledgement, wherein there is a fixed number of compressed PDCCH reception feedback bits allocated for the compressed PDCCH reception feedback information, wherein the fixed number is the same as the first number.

[0112] Example 7. The apparatus of example 6, wherein the apparatus is further caused to: receive, from the network entity, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is transmitted based on the information related to compressed PDCCH reception reporting received from the network entity; wherein the information related to compressed PDCCH reception reporting received from the network entity comprises the fixed number of compressed PDCCH reception feedback bits allocated for the compressed PDCCH reception feedback information.

[0113] Example 8. The apparatus of example 1 , wherein the apparatus is further caused to: determine a number of groups of physical downlink shared channel candidates, wherein the physical downlink shared channel candidates are among the at least one downlink data transmission. The determined number of groups of physical downlink shared channel candidates may be equal to 1 (there is only 1 group of physical downlink shared channel candidates) or greater than 1 (there are two or more groups of physical downlinkshared channel candidates).

[0114] Example 9. The apparatus of example 8, wherein the apparatus is further caused to: count, for each of the groups, a number of the physical downlink shared channel candidates for which a downlink assignment was correctly received; wherein the compressed PDCCH reception feedback information transmitted to the network entity comprises the count of the number the physical downlink shared channel candidates for which a downlink assignment was correctly received for each of the groups of physical downlink shared channel candidates.

[0115] Example 10. The apparatus of example 9, wherein the physical downlink shared channel candidates for which a downlink assignment was correctly received that are counted are physical downlink shared channel candidates for which the apparatus failed to decode a transport block.

[0116] Example 11. The apparatus of any of examples 9 to 10, wherein each group of the physical downlink shared channel candidates only comprises physical downlink shared channel candidates for which the apparatus failed to decode a transport block.

[0117] Example 12. The apparatus of any of examples 9 to 11 , wherein the codebook is a Type 1 HARQ-ACK codebook.

[0118] Example 13. The apparatus of any of examples 8 to 12, wherein: a number of bits that are used to transmit the compressed PDCCH reception feedback information for each of the groups of physical downlink shared channel candidates is equal to a ceiling of a logarithm base 2 of a maximum number of the physical downlink shared channel candidates per group of physical downlink shared channel candidates, and a total number of bits used to transmit the compressed PDCCH reception feedback information is equal to the number of groups of physical downlink shared channel candidates multiplied by the number of bits used to transmit the compressed PDCCH reception feedback information per group of physical downlink shared channel candidates.

[0119] Example 14. The apparatus of any of examples 8 to 13, wherein the apparatus is further caused to: receive, from the network entity, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is transmitted based on the information related to compressed PDCCH reception reporting received from the network entity; wherein the information related to compressed PDCCH reception reporting received from the network entity comprises at least one or more of: the number of groups of physical downlink shared channel candidates, or a maximum number of physical downlink shared channel candidates per group of physical downlink shared channel candidates.

[0120] Example 15. The apparatus of example 1 , wherein the apparatus is further caused to: determine a number of groups of the at least one downlink data transmission. The determined number of groups of the at least one downlink data transmission may be equal to 1 (there is only one group of the at least one downlink data transmission) or greater than 1 (there are two or more groups of the at least one downlinkdata transmission).

[0121] Example 16. The apparatus of example 15, wherein the apparatus is further caused to: count, for each group of the number of groups of the at least one downlink data transmission, a number of the at least one downlink data transmission for which a downlink assignment was not correctly received; wherein the compressed PDCCH reception feedback information transmitted to the network entity comprises the count of the number of the at least one downlink data transmission for which a downlink assignment was not correctly received for each of the groups of the at least one downlink data transmission.

[0122] Example 17. The apparatus of example 16, wherein the codebook is a Type 2 HARQ-ACK codebook.

[0123] Example 18. The apparatus of any of examples 16 to 17, wherein : a number of bits that are used to transmit the compressed PDCCH reception feedback information for each of the groups of the at least one downlink data transmission is equal to a ceiling of a logarithm base 2 of a maximum number of the at least one downlink data transmission per group of the at least one downlink data transmission, and a total number of bits used to transmit the compressed PDCCH reception feedback information is equal to the number of groups of the at least one downlink data transmission multiplied by the number of bits used to transmit the compressed PDCCH reception feedback information per group of the at least one downlink data transmission.

[0124] Example 19. The apparatus of any of examples 15 to 18, wherein the apparatus is further caused to: receive, from the network entity, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is transmitted based on the information related to compressed PDCCH reception reporting received from the network entity; wherein the information related to compressed PDCCH reception reporting received from the network entity comprises at least one or more of: the number of groups of at least one downlink data transmission, or a maximum number of at least one downlink data transmission per group of at least one downlink data transmission.

[0125] Example 20. The apparatus of example 1 , wherein the apparatus is further caused to: count a number of the physical downlink shared channel candidates for which a downlink assignment was correctly received; wherein the physical downlink shared channel candidates are among the at least one downlink data transmission; wherein the compressed PDCCH reception feedback information transmitted to the network entity comprises the count of the number of the physical downlink shared channel candidates for which a downlink assignment was correctly received.

[0126] Example 21 . The apparatus of example 20, wherein the physical downlink shared channel candidates for which a downlink assignment was correctly received that are counted are physical downlink shared channel candidates for which the apparatus failed to decode a transport block.

[0127] Example 22. The apparatus of any of examples 20 to 21 , wherein the codebook is a Type 1HARQ-ACK codebook.

[0128] Example 23. The apparatus of any of examples 20 to 22, wherein a number of bits that are used to transmit the compressed PDCCH reception feedback information is equal to a ceiling of a logarithm base 2 of a maximum number of the physical downlink shared channel candidates.

[0129] Example 24. The apparatus of example 23, wherein the apparatus is further caused to: receive, from the network entity, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is transmitted based on the information related to compressed PDCCH reception reporting received from the network entity; wherein the information related to compressed PDCCH reception reporting received from the network entity comprises the maximum number of physical downlink shared channel candidates.

[0130] Example 25. The apparatus of any of examples 20 to 24, wherein the apparatus is further caused to: determine a number of groups of the physical downlink shared channel candidates; wherein the count of the number of the physical downlink shared channel candidates for which a downlink assignment was correctly received is performed for each of the groups of the physical downlink shared channel candidates; wherein the compressed PDCCH reception feedback information transmitted to the network entity comprises the count of the number the physical downlink shared channel candidates for which a downlink assignment was correctly received for each of the groups of physical downlink shared channel candidates. The determined number of groups of the physical downlink shared channel candidates may be equal to 1 (there is only 1 group of the physical downlink shared channel candidates) or greater than 1 (there are two or more groups of the physical downlink shared channel candidates).

[0131] Example 26. The apparatus of example 25, wherein each group of the physical downlink shared channel candidates only comprises physical downlink shared channel candidates for which the apparatus failed to decode a transport block.

[0132] Example 27. The apparatus of any of examples 25 to 26, wherein: a number of bits that are used to transmit the compressed PDCCH reception feedback information for each of the groups of physical downlink shared channel candidates is equal to a ceiling of a logarithm base 2 of a maximum number of the physical downlink shared channel candidates per group of physical downlink shared channel candidates, and a total number of bits used to transmit the compressed PDCCH reception feedback information is equal to the number of groups of physical downlink shared channel candidates multiplied by the number of bits used to transmit the compressed PDCCH reception feedback information per group of physical downlink shared channel candidates.

[0133] Example 28. The apparatus of any of examples 25 to 26, wherein the apparatus is further caused to: receive, from the network entity, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is transmitted based on the information related tocompressed PDCCH reception reporting received from the network entity; wherein the information related to compressed PDCCH reception reporting received from the network entity comprises at least one or more of: the number of groups of physical downlink shared channel candidates, or a maximum number of physical downlink shared channel candidates per group of physical downlink shared channel candidates.

[0134] Example 29. The apparatus of example 1 , wherein the apparatus is further caused to: count a number of the at least one downlink data transmission for which a downlink assignment was not correctly received; wherein the compressed PDCCH reception feedback information transmitted to the network entity comprises the count of the number of the at least one downlink data transmission for which a downlink assignment was not correctly received.

[0135] Example 30. The apparatus of example 29, wherein the codebook is a Type 2 HARQ-ACK codebook.

[0136] Example 31 . The apparatus of any of examples 29 to 30, wherein a number of bits that are used to transmit the compressed PDCCH reception feedback information is equal to a ceiling of a logarithm base 2 of a maximum number of the at least one downlink data transmission.

[0137] Example 32. The apparatus of example 31 , wherein the apparatus is further caused to: receive, from the network entity, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is transmitted based on the information related to compressed PDCCH reception reporting received from the network entity; wherein the information related to compressed PDCCH reception reporting received from the network entity comprises the maximum number of the at least one downlink data transmission.

[0138] Example 33. The apparatus of any of examples 29 to 32, wherein the apparatus is further caused to: determine a number of groups of the at least one downlink data transmission; wherein the count of the number of the at least one downlink data transmission for which a downlink assignment was not correctly received is performed for each of the groups of the at least one downlink data transmission; wherein the compressed PDCCH reception feedback information transmitted to the network entity comprises the count of the number the at least one downlink data transmission for which a downlink assignment was not correctly received for each of the groups of the at least one downlink data transmission. The determined number of groups of the at least one downlink data transmission may be equal to 1 (there is only 1 group of at least one downlink data transmission) or greater than 1 (there are two or more groups of at least one downlink data transmission).

[0139] Example 34. The apparatus of example 33, wherein: a number of bits that are used to transmit the compressed PDCCH reception feedback information for each of the groups of the at least one downlink data transmission is equal to a ceiling of a logarithm base 2 of a maximum number of the at least one downlink data transmission per group of the at least one downlink data transmission, and a total numberof bits used to transmit the compressed PDCCH reception feedback information is equal to the number of groups of the at least one downlink data transmission multiplied by the number of bits used to transmit the compressed PDCCH reception feedback information per group of the at least one downlink data transmission.

[0140] Example 35. The apparatus of any of examples 33 to 34, wherein the apparatus is further caused to: receive, from the network entity, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is transmitted based on the information related to compressed PDCCH reception reporting received from the network entity; wherein the information related to compressed PDCCH reception reporting received from the network entity comprises at least one or more of: the number of groups of at least one downlink data transmission, or a maximum number of at least one downlink data transmission per group of at least one downlink data transmission.

[0141] Example 36. An apparatus including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: transmit, to the user equipment, data with at least one downlink data transmission of a transport block; transmit, to the user equipment, at least one downlink control transmission; and receive, from the user equipment, uplink control information comprising: a hybrid-ARQ codebook, and compressed PDCCH reception feedback information; wherein the compressed PDCCH reception feedback information received from the user equipment is based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received.

[0142] Example 37. The apparatus of example 36, wherein the apparatus is further caused to, based on the compressed PDCCH reception feedback information received from the user equipment: perform link adaptation, or perform retransmission of the at least one downlink data transmission of a transport block, or determine an aggregation level for subsequent transmission of downlink control, or determine whether unsuccessful reception of the at least one downlink data transmission was due to a failure related to the transmission of the at least one downlink control transmission, or due to a failure to decode the at least one downlink data transmission of a transport block.

[0143] Example 38. The apparatus of any of examples 36 to 37, wherein: the compressed PDCCH reception feedback information for two or more downlink data transmissions of the at least one downlink data transmission is received with one bit, based on the logical bundling operation, wherein the logical bunding operation comprises a logical AND operation or a logical OR operation, and the logical bundlingoperation is performed with a first input and a second input, wherein the first input comprises whether or not the at least one downlink data transmission of a transport block is correctly received, and wherein the second input comprises whether or not the at least one downlink control transmission is correctly received.

[0144] Example 39. The apparatus of example 38, wherein the two or more downlink data transmissions for which the compressed PDCCH feedback information is received with one bit are in at least one or more of: a common time domain, or a common frequency domain, or a common spatial domain.

[0145] Example 40. The apparatus of any of examples 38 to 39, wherein the compressed PDCCH reception feedback information is received with a number of bits corresponding to: a number of one or more bundling windows, wherein a bundling window comprises a bundling window size that corresponds to a number of the two or more downlink data transmissions that are bundled into one bit.

[0146] Example 41 . The apparatus of example 40, wherein the apparatus is further caused to: transmit, to the user equipment, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is received based on the information related to compressed PDCCH reception reporting transmitted to the user equipment; wherein the information related to compressed PDCCH reception reporting transmitted to the user equipment comprises at least one or more of: the bundling window size, or the number of one or more bundling windows each comprising the bundling window size that corresponds to the number of the two or more downlink data transmissions that are bundled into one bit.

[0147] Example 42. The apparatus of any of examples 36 to 37, wherein the compressed PDCCH reception feedback information is received for up to a first number of transport blocks corresponding to the at least one downlink data transmission with a negative acknowledgement, wherein there is a fixed number of compressed PDCCH reception feedback bits allocated for the compressed PDCCH reception feedback information, and wherein the fixed number is the same as the first number.

[0148] Example 43. The apparatus of example 42, wherein the apparatus is further caused to: transmit, to the user equipment, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is received based on the information related to compressed PDCCH reception reporting transmitted to the user equipment; wherein the information related to compressed PDCCH reception reporting transmitted to the user equipment comprises the fixed number of compressed PDCCH reception feedback bits allocated for the compressed PDCCH reception feedback information.

[0149] Example 44. The apparatus of any of examples 36 to 37, wherein the compressed PDCCH reception feedback information received from the user equipment comprises a count of a number physical downlink shared channel candidates for which a downlink assignment was correctly received for each group of physical downlink shared channel candidates of a number of groups of physical downlink sharedchannel candidates, wherein the physical downlink shared channel candidates are among the at least one downlink data transmission. The number of groups of physical downlink shared channel candidates may be equal to 1 (there is only 1 group of physical downlink shared channel candidates) or greater than 1 (there are two or more groups of physical downlink shared channel candidates).

[0150] Example 45. The apparatus of example 44, wherein the physical downlink shared channel candidates for which a downlink assignment was correctly received included within the count are physical downlink shared channel candidates for which there was a failure to decode a transport block.

[0151] Example 46. The apparatus of any of examples 44 to 45, wherein each group of the physical downlink shared channel candidates only comprises physical downlink shared channel candidates for which there was a failure to decode a transport block.

[0152] Example 47. The apparatus of any of examples 44 to 46, wherein the codebook is a Type 1 HARQ-ACK codebook.

[0153] Example 48. The apparatus of any of examples 44 to 47, wherein: a number of bits with which the compressed PDCCH reception feedback information is received for each group of physical downlink shared channel candidates is equal to a ceiling of a logarithm base 2 of a maximum number of physical downlink shared channel candidates per group of physical downlink shared channel candidates, and a total number of bits with which the compressed PDCCH reception feedback information is received is equal to the number of the groups of physical downlink shared channel candidates multiplied by the number of bits with which the compressed PDCCH feedback information is received per group of physical downlink shared channel candidates.

[0154] Example 49. The apparatus of any of examples 44 to 48, wherein the apparatus is further caused to: transmit, to the user equipment, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is received based on the information related to compressed PDCCH reception reporting transmitted to the user equipment; wherein the information related to compressed PDCCH reception reporting transmitted to the user equipment comprises at least one or more of: the number of groups of physical downlink shared channel candidates, or a number of physical downlink shared channel candidates per group of physical downlink shared channel candidates.

[0155] Example 50. The apparatus of any of examples 36 to 37, wherein the compressed PDCCH reception feedback information received from the user equipment comprises a count of a number of the at least one downlink data transmission for which a downlink assignment was not correctly received for each group of the at least one downlink data transmission of a number of groups of the at least one downlink data transmission. The number of groups of the at least one downlink data transmission may be equal to 1 (there is only 1 group of the at least one downlink data transmission) or greater than 1 (there are two or more groups of the at least one downlink data transmission).

[0156] Example 51. The apparatus of example 50, wherein the codebook is a Type 2 HARQ-ACK codebook.

[0157] Example 52. The apparatus of any of examples 50 to 51 , wherein: a number of bits with which the compressed PDCCH reception feedback information is received for each group of the at least one downlink data transmission is equal to a ceiling of a logarithm base 2 of a number of the at least one downlink data transmission per group of the at least one downlink data transmission, and a total number of bits with which the compressed PDCCH reception feedback information is received is equal to the number of the groups of the at least one downlink data transmission multiplied by the number of bits with which the compressed PDCCH feedback information per group of the at least one downlink data transmission.

[0158] Example 53. The apparatus of any of examples 50 to 52, wherein the apparatus is further caused to: transmit, to the user equipment, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is received based on the information related to compressed PDCCH reception reporting transmitted to the user equipment; wherein the information related to compressed PDCCH reception reporting transmitted to the user equipment comprises at least one or more of: the number of groups of at least one downlink data transmission, or a number of at least one downlink data transmission per group of physical downlink shared channel candidates.

[0159] Example 54. The apparatus of any of examples 36 to 37, wherein the compressed PDCCH reception feedback information received from the user equipment comprises a count of a number of physical downlink shared channel candidates for which a downlink assignment was correctly received, wherein the physical downlink shared channel candidates are among the at least one downlink data transmission.

[0160] Example 55. The apparatus of example 54, wherein the physical downlink shared channel candidates for which a downlink assignment was correctly received that are counted are physical downlink shared channel candidates for which there was a failure to decode a transport block.

[0161] Example 56. The apparatus of any of examples 54 to 55, wherein the codebook is a Type 1 HARQ-ACK codebook.

[0162] Example 57. The apparatus of any of examples 54 to 56, wherein a number of bits with which the compressed PDCCH reception feedback information is received is equal to a ceiling of a logarithm base 2 of a maximum number of the physical downlink shared channel candidates.

[0163] Example 58. The apparatus of example 57, wherein the apparatus is further caused to: transmit, to the user equipment, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is received based on the information related to compressed PDCCH reception reporting transmitted to the user equipment; wherein the information relatedto compressed PDCCH reception reporting transmitted to the user equipment comprises the maximum number of physical downlink shared channel candidates.

[0164] Example 59. The apparatus of any of examples 54 to 58, wherein: the count of the number of the physical downlink shared channel candidates for which a downlink assignment was correctly received comprises a count of the number of the physical downlink shared channel candidates for which a downlink assignment was correctly received for each group of a number the groups of the physical downlink shared channel candidates, and the compressed PDCCH reception feedback information received from the user equipment comprises the count of the number of the physical downlink shared channel candidates for which a downlink assignment was correctly received for each group of the number the groups of the physical downlink shared channel candidates. The number of groups of the physical downlink shared channel candidates may be equal to 1 (there is only 1 group of the physical downlink shared channel candidates) or greater than 1 (there are two or more groups of the physical downlink shared channel candidates).

[0165] Example 60. The apparatus of example 59, wherein each group of the physical downlink shared channel candidates only comprises physical downlink shared channel candidates for which there was a failure to decode a transport block.

[0166] Example 61 . The apparatus of any of examples 59 to 60, wherein: a number of bits with which the compressed PDCCH reception feedback information is received for each group of physical downlink shared channel candidates is equal to a ceiling of a logarithm base 2 of a maximum number of the physical downlink shared channel candidates per group of physical downlink shared channel candidates, and a total number of bits with which the compressed PDCCH reception feedback information is received is equal to the number of groups of physical downlink shared channel candidates multiplied by the number of bits with which the compressed PDCCH reception feedback information is received per group of physical downlink shared channel candidates.

[0167] Example 62. The apparatus of example 61, wherein the apparatus is further caused to: transmit, to the user equipment, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is received based on the information related to compressed PDCCH reception reporting transmitted to the user equipment; wherein the information related to compressed PDCCH reception reporting transmitted to the user equipment comprises at least one or more of: the number of groups of physical downlink shared channel candidates, or the maximum number of physical downlink shared channel candidates per group of physical downlink shared channel candidates.

[0168] Example 63. The apparatus of any of examples 36 to 37, wherein the compressed PDCCH reception feedback information received from the user equipment comprises a count of a number of the at least one downlink data transmission for which a downlink assignment was not correctly received.

[0169] Example 64. The apparatus of example 63, wherein the codebook is a Type 2 HARQ-ACK codebook.

[0170] Example 65. The apparatus of any of examples 63 to 64, wherein a number of bits with which the compressed PDCCH reception feedback information is received is equal to a ceiling of a logarithm base 2 of a maximum number of the at least one downlink data transmission.

[0171] Example 66. The apparatus of example 65, wherein the apparatus is further caused to: transmit, to the user equipment, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is received based on the information related to compressed PDCCH reception reporting transmitted to the user equipment; wherein the information related to compressed PDCCH reception reporting transmitted to the user equipment comprises the maximum number of the at least one downlink data transmission.

[0172] Example 67. The apparatus of any of examples 63 to 66, wherein: the count of the number of the at least one downlink data transmission for which a downlink assignment was not correctly received comprises a count of the number of the at least one downlink data transmission for which a downlink assignment was not correctly received for each group of a number the groups of the at least one downlink data transmission, and the compressed PDCCH reception feedback information received from the user equipment comprises the count of the number of the at least one downlink data transmission for which a downlink assignment was not correctly received for each group of the number the groups of the at least one downlink data transmission . The number of groups of the at least one downlink data transmission may be equal to 1 (there is only 1 group of the at least one downlink data transmission) or greater than 1 (there are two or more groups of the at least one downlink data transmission).

[0173] Example 68. The apparatus of example 67, wherein: a number of bits with which the compressed PDCCH reception feedback information is received for each of the groups of the at least one downlink data transmission is equal to a ceiling of a logarithm base 2 of a maximum number of the at least one downlink data transmission per group of the at least one downlink data transmission, and a total number of bits with which the compressed PDCCH reception feedback information is received is equal to the number of groups of the at least one downlink data transmission multiplied by the number of bits with which the compressed PDCCH reception feedback information is received per group of the at least one downlink data transmission.

[0174] Example 69. The apparatus of example 68, wherein the apparatus is further caused to: transmit, to the user equipment, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is received based on the information related to compressed PDCCH reception reporting transmitted to the user equipment; wherein the information related to compressed PDCCH reception reporting transmitted to the user equipment comprises at least one ormore of: the number of groups of at least one downlink data transmission, or the maximum number of at least one downlink data transmission per group of at least one downlink data transmission.

[0175] Example 70. A method including: determining whether at least one downlink data transmission of a transport block is correctly received; generating a hybrid-ARQ codebook based on whether the at least one downlink data transmission of a transport block is correctly received; determining PDCCH reception feedback information corresponding to each entry of the generated hybrid-ARQ codebook based on whether a downlink control transmission was correctly received corresponding to each entry of the generated hybrid-ARQ codebook; compressing the PDCCH reception feedback information based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received; and transmitting, to a network entity, uplink control information comprising: the hybrid-ARQ codebook, and the compressed PDCCH reception feedback information.

[0176] Example 71. A method including: transmitting, to the user equipment, data with at least one downlink data transmission of a transport block; transmitting, to the user equipment, at least one downlink control transmission; and receiving, from the user equipment, uplink control information comprising: a hybrid-ARQ codebook, and compressed PDCCH reception feedback information; wherein the compressed PDCCH reception feedback information received from the user equipment is based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received .

[0177] Example 72. An apparatus including: means for determining whether at least one downlink data transmission of a transport block is correctly received; means for generating a hybrid-ARQ codebook based on whether the at least one downlink data transmission of a transport block is correctly received; means for determining PDCCH reception feedback information corresponding to each entry of the generated hybrid-ARQ codebook based on whether a downlink control transmission was correctly received corresponding to each entry of the generated hybrid-ARQ codebook; means for compressing the PDCCH reception feedback information based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for thePDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received; and means for transmitting, to a network entity, uplink control information comprising: the hybrid-ARQ codebook, and the compressed PDCCH reception feedback information.

[0178] Example 73. An apparatus including: means for transmitting, to the user equipment, data with at least one downlink data transmission of a transport block; means for transmitting, to the user equipment, at least one downlink control transmission; and means for receiving, from the user equipment, uplink control information comprising: a hybrid-ARQ codebook, and compressed PDCCH reception feedback information; wherein the compressed PDCCH reception feedback information received from the user equipment is based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received.

[0179] Example 74. A computer readable medium including instructions stored thereon for performing at least the following: determining whether at least one downlink data transmission of a transport block is correctly received; generating a hybrid-ARQ codebook based on whether the at least one downlink data transmission of a transport block is correctly received; determining PDCCH reception feedback information corresponding to each entry of the generated hybrid-ARQ codebook based on whether a downlink control transmission was correctly received corresponding to each entry of the generated hybrid-ARQ codebook; compressing the PDCCH reception feedback information based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received; and transmitting, to a network entity, uplink control information comprising: the hybrid-ARQ codebook, and the compressed PDCCH reception feedback information.

[0180] Example 75. A computer readable medium including instructions stored thereon for performing at least the following: transmitting, to the user equipment, data with at least one downlink data transmission of a transport block; transmitting, to the user equipment, at least one downlink control transmission; andreceiving, from the user equipment, uplink control information comprising: a hybrid-ARQ codebook, and compressed PDCCH reception feedback information; wherein the compressed PDCCH reception feedback information received from the user equipment is based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received .

[0181] References to a ‘computer’, ‘processor’, etc. should be understood to encompass not only computers having different architectures such as single / multi-processor architectures and sequential or parallel architectures but also specialized circuits such as field-programmable gate arrays (FPGAs), application specific circuits (ASICs), signal processing devices and other processing circuitry. References to computer program, instructions, code etc. should be understood to encompass software for a programmable processor or firmware such as, for example, the programmable content of a hardware device whether instructions for a processor, or configuration settings for a fixed-function device, gate array or programmable logic device etc.

[0182] The memories as described herein may be implemented using any suitable data storage technology, such as semiconductor based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, non-transitory memory, transitory memory, fixed memory and removable memory. The memories may comprise a database for storing data.

[0183] The term "non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0184] As used herein, the term ‘circuitry’ may refer to the following: (a) hardware circuit implementations, such as implementations in analog and / or digital circuitry, and (b) combinations of circuits and software (and / or firmware), such as (as applicable): (I) a combination of processor(s) or (ii) portions of processor(s) / software including digital signal processor(s), software, and memories that work together to cause an apparatus to perform various functions, and (c) circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present. As a further example, as used herein, the term ‘circuitry’ would also cover an implementation of merely a processor (or multiple processors) or a portion of a processor and its (or their) accompanying software and / or firmware. The term ‘circuitry’ would also cover, for example and if applicable to the particular element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or another network device.

[0185] It should be understood that the foregoing description is only illustrative. Various alternatives and modifications may be devised by those skilled in the art. For example, features recited in the various dependent claims could be combined with each other in any suitable combination(s). In addition, features from different example embodiments described above could be selectively combined into a new example embodiment. Accordingly, this description is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.

[0186] The following acronyms and abbreviations that may be found in the specification and / or the drawing figures are given as follows (the abbreviations and acronyms may be appended / combined with each other or with other characters using e.g. a dash, hyphen, slash, letter, or number, and may be case insensitive):3GPP third generation partnership project4G fourth generation5G fifth generation5GC 5G core network6G sixth generationACK acknowledgementAlt alternate / alternativeAMF access and mobility management functionA / N acknowledgement / negative acknowledgementARQ automatic repeat requestASIC application-specific integrated circuit b bit (e.g. b1)BWP bandwidth partCB codebookCBG codeblock groupCC component carrierCD compact / computer discC-DAI counter downlink assignment indicator / indexCPU central processing unitCU central unit or centralized unitDAI downlink assignment indicator / indexDC dual connectivityDCI downlink control informationDL downlinkDRX discontinuous receptionDSP digital signal processorDTX discontinuous transmissionDU distributed unitDVD digital versatile disc eNB evolved Node B (e.g., an LTE base station)EN-DC E-UTRAN new radio - dual connectivity en-gNB node providing NR user plane and control plane protocol terminations towards the UE, and acting as a secondary node in EN-DCEPC evolved packet coreE-UTRA evolved UMTS terrestrial radio access, i.e., the LTE radio access technologyE-UTRAN E-UTRA networkF1 interface between the CU and the DUFB feedbackFPGA field-programmable gate array gNB generalized node B, base station for 5G / NR, i.e., a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GCHARQ hybrid automatic repeat requestHARQ-ACK HARQ acknowledgementIAB integrated access and backhaul l / F interfaceI / O input / outputLTE long term evolution (4G)MAC medium access controlMAC CE medium access control control elementMCS modulation and coding schemeMME mobility management entityMRO mobility robustness optimizationNACK negative acknowledgementNCE network control element ng or NG new generation ng-eNB new generation eNBNG-RAN new generation radio access networkNR new radioNW networkN / W networkPDA personal digital assistantPDCCH physical downlink control channelPDCP packet data convergence protocolPDSCH physical downlink shared channelPHY physical layerPUCCH physical uplink control channelPUSCH physical uplink shared channelRAM random access memoryRAN radio access networkRB resource blockRLC radio link controlROM read-only memoryRRC radio resource controlRU radio unitRV redundancy versionRx receive, or receiver, or receptionS1 interface between the mobility management entity (MME) in the EPC and the evolved Node B's in the E-UTRANSDAP service data adaptation protocolSGW serving gatewaySMF session management functionSON self-organizing / optimizing networkSU-MIMO single user multiple input multiple outputTB transport blockT-DAI total downlink assignment indicator / indexTRP transmission reception pointTTI transmission time intervalTx transmit, or transmitter, or transmissionUAV unmanned aerial vehicleUCI uplink control informationUE user equipment (e.g., a wireless, typically mobile device)Ul user interface uplinkUMTS Universal Mobile Telecommunications SystemUPF user plane function USB universal serial busX2 network interface between RAN nodes and between RAN and the core networkXn network interface between NG-RAN nodes

Claims

CLAIMS1 . An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine whether at least one downlink data transmission of a transport block is correctly received; generate a hybrid-ARQ codebook based on whether the at least one downlink data transmission of a transport block is correctly received; determine PDCCH reception feedback information corresponding to each entry of the generated hybrid-ARQ codebook based on whether a downlink control transmission was correctly received corresponding to each entry of the generated hybrid-ARQ codebook; compress the PDCCH reception feedback information based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received; and transmit, to a network entity, uplink control information comprising: the hybrid-ARQ codebook, and the compressed PDCCH reception feedback information.

2. The apparatus of claim 1 , wherein: the compressed PDCCH reception feedback information is transmitted for two or more downlink data transmissions of the at least one downlink data transmission with one bit, based on the logical bundling operation that is performed using a logical AND operation or a logical OR operation, and the logical bundling operation is performed with a first input and a second input, wherein the first input comprises whether or not the at least one downlink data transmission of a transport block is correctly received, and wherein the second input comprises whether or not the at least one downlink control transmission is correctly received.

3. The apparatus of claim 2, wherein the two or more downlink data transmissions for which the compressed PDCCH feedback information is transmitted with one bit are in at least one or more of: a common time domain, or a common frequency domain, or a common spatial domain.

4. The apparatus of any of claims 2 to 3, wherein the compressed PDCCH reception feedback information is38transmitted using a number of bits corresponding to a number of one or more bundling windows, wherein a bundling window comprises a bundling window size that corresponds to a number of the two or more downlink data transmissions that are bundled into one bit.

5. The apparatus of claim 4, wherein the apparatus is further caused to: receive, from the network entity, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is transmitted based on the information related to compressed PDCCH reception reporting received from the network entity; wherein the information related to compressed PDCCH reception reporting received from the network entity comprises at least one or more of: the bundling window size, or the number of one or more bundling windows each comprising the bundling window size that corresponds to the number of the two or more downlink data transmissions that are bundled into one bit.

6. The apparatus of claim 1 , wherein the compressed PDCCH reception feedback information is transmitted to the network entity for up to a first number of transport blocks corresponding to the at least one downlink data transmission with a negative acknowledgement, wherein there is a fixed number of compressed PDCCH reception feedback bits allocated for the compressed PDCCH reception feedback information, wherein the fixed number is the same as the first number.

7. The apparatus of claim 6, wherein the apparatus is further caused to: receive, from the network entity, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is transmitted based on the information related to compressed PDCCH reception reporting received from the network entity; wherein the information related to compressed PDCCH reception reporting received from the network entity comprises the fixed number of compressed PDCCH reception feedback bits allocated for the compressed PDCCH reception feedback information.

8. The apparatus of claim 1 , wherein the apparatus is further caused to: count a number of the physical downlink shared channel candidates for which a downlink assignment was correctly received; wherein the physical downlink shared channel candidates are among the at least one downlink data transmission; wherein the compressed PDCCH reception feedback information transmitted to the network entity comprises the count of the number of the physical downlink shared channel candidates for which a downlink assignment was correctly received.

9. The apparatus of claim 1 , wherein the apparatus is further caused to: determine a number of groups of physical downlink shared channel candidates, wherein the physical downlink shared channel candidates are among the at least one downlink data transmission.

10. The apparatus of claim 9, wherein the apparatus is further caused to: count, for each of the groups, a number of the physical downlink shared channel candidates for which a downlink assignment was correctly received; wherein the compressed PDCCH reception feedback information transmitted to the network entity comprises the count of the number the physical downlink shared channel candidates for which a downlink assignment was correctly received for each of the groups of physical downlink shared channel candidates.

11. The apparatus of any of claims 8 to 10, wherein the physical downlink shared channel candidates for which a downlink assignment was correctly received that are counted are physical downlink shared channel candidates for which the apparatus failed to decode a transport block.

12. The apparatus of any of claims 9 to 11 , wherein each group of the physical downlink shared channel candidates only comprises physical downlink shared channel candidates for which the apparatus failed to decode a transport block.

13. The apparatus of any of claims 8 to 12, wherein the codebook is a Type 1 HARQ-ACK codebook.

14. The apparatus of any of claims 8 to 12, wherein: a number of bits that are used to transmit the compressed PDCCH reception feedback information is equal to a ceiling of a logarithm base 2 of a maximum number of the physical downlink shared channel candidates.

15. The apparatus of any of claim 9 to 12, wherein: a number of bits that are used to transmit the compressed PDCCH reception feedback information for each of the groups of physical downlink shared channel candidates is equal to a ceiling of a logarithm base 2 of a maximum number of the physical downlink shared channel candidates per group of physical downlink shared channel candidates, and a total number of bits used to transmit the compressed PDCCH reception feedback information is equal to the number of groups of physical downlink shared channel candidates multiplied by the number of bits used to transmit the compressed PDCCH reception feedback information per group of physical downlinkshared channel candidates.

16. The apparatus of any of claims 8 to 15, wherein the apparatus is further caused to: receive, from the network entity, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is transmitted based on the information related to compressed PDCCH reception reporting received from the network entity; wherein the information related to compressed PDCCH reception reporting received from the network entity comprises at least one or more of: the number of groups of physical downlink shared channel candidates, or a maximum number of physical downlink shared channel candidates per group of physical downlink shared channel candidates or a maximum number of physical downlink shared channel candidates.

17. The apparatus of claim 1 , wherein the apparatus is further caused to: count a number of the at least one downlink data transmission for which a downlink assignment was not correctly received; wherein the compressed PDCCH reception feedback information transmitted to the network entity comprises the count of the number of the at least one downlink data transmission for which a downlink assignment was not correctly received.

18. The apparatus of claim 1 , wherein the apparatus is further caused to: determine a number of groups of the at least one downlink data transmission.

19. The apparatus of claim 18, wherein the apparatus is further caused to: count, for each group of the number of groups of the at least one downlink data transmission, a number of the at least one downlink data transmission for which a downlink assignment was not correctly received; wherein the compressed PDCCH reception feedback information transmitted to the network entity comprises the count of the number of the at least one downlink data transmission for which a downlink assignment was not correctly received for each of the groups of the at least one downlink data transmission.

20. The apparatus of any of claims 17 to 19, wherein the codebook is a Type 2 HARQ-ACK codebook.

21. The apparatus of any of claims 17 to 20, wherein: a number of bits that are used to transmit the compressed PDCCH reception feedback information is equal to a ceiling of a logarithm base 2 of a maximum number of the at least one downlink data transmission.

22. The apparatus of any of claims 18 to 21 , wherein: a number of bits that are used to transmit the compressed PDCCH reception feedback information for each of the groups of the at least one downlink data transmission is equal to a ceiling of a logarithm base 2 of a maximum number of the at least one downlink data transmission per group of the at least one downlink data transmission, and a total number of bits used to transmit the compressed PDCCH reception feedback information is equal to the number of groups of the at least one downlink data transmission multiplied by the number of bits used to transmit the compressed PDCCH reception feedback information per group of the at least one downlink data transmission.

23. The apparatus of any of claims 17 to 22, wherein the apparatus is further caused to: receive, from the network entity, information related to compressed PDCCH reception reporting; wherein the compressed PDCCH reception feedback information is transmitted based on the information related to compressed PDCCH reception reporting received from the network entity; wherein the information related to compressed PDCCH reception reporting received from the network entity comprises at least one or more of: the number of groups of at least one downlink data transmission, or a maximum number of at least one downlink data transmission per group of at least one downlink data transmission or a maximum number of the at least one downlink data transmission.

24. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: transmit, to the user equipment, data with at least one downlink data transmission of a transport block; transmit, to the user equipment, at least one downlink control transmission; and receive, from the user equipment, uplink control information comprising: a hybrid-ARQ codebook, and compressed PDCCH reception feedback information; wherein the compressed PDCCH reception feedback information received from the user equipment is based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received.

25. A method comprising: determining whether at least one downlink data transmission of a transport block is correctly received; generating a hybrid-ARQ codebook based on whether the at least one downlink data transmission of a transport block is correctly received; determining PDCCH reception feedback information corresponding to each entry of the generated hybrid-ARQ codebook based on whether a downlink control transmission was correctly received corresponding to each entry of the generated hybrid-ARQ codebook; compressing the PDCCH reception feedback information based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received; and transmitting, to a network entity, uplink control information comprising: the hybrid-ARQ codebook, and the compressed PDCCH reception feedback information.

26. A method comprising: transmitting, to the user equipment, data with at least one downlink data transmission of a transport block; transmitting, to the user equipment, at least one downlink control transmission; and receiving, from the user equipment, uplink control information comprising: a hybrid-ARQ codebook, and compressed PDCCH reception feedback information; wherein the compressed PDCCH reception feedback information received from the user equipment is based on at least one or more of: a logical bundling operation across at least two bits of the PDCCH reception feedback information, or a fixed number of bits allocated for the PDCCH reception feedback information, or whether the at least one downlink data transmission of a transport block is correctly received, or whether the at least one downlink data transmission of a transport block is not correctly received, or whether the at least one downlink control transmission is correctly received, or whether the at least one downlink control transmission is not correctly received.

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