WO2025156498A1

WO2025156498A1 - Methods, devices, and systems for harq process mechanism enhancement

Info

Publication number: WO2025156498A1
Application number: PCT/CN2024/092156
Authority: WO
Inventors: Jing Shi; Xianghui HAN; Wei Gou; Shuaihua KOU; Jian Li
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2024-05-10
Filing date: 2024-05-10
Publication date: 2025-07-31
Anticipated expiration: 2026-11-10

Abstract

The present disclosure describes methods, system, and devices for hybrid automatic repeat request (HARQ) process mechanism enhancement. One method includes receiving, by a user equipment (UE), a first physical downlink shared channel (PDSCH) in a first cell, and determining, by the UE, a HARQ acknowledgement (HARQ-ACK) feedback for the first PDSCH corresponding to a HARQ process, for transmitting on a second cell. Another method includes sending, by a base station, a first PDSCH in a first cell, and receiving, by the base station, a HARQ-ACK feedback for the first PDSCH corresponding to a HARQ process, via a second cell.

Description

METHODS, DEVICES, AND SYSTEMS FOR HARQ PROCESS MECHANISM ENHANCEMENT

TECHNICAL FIELD

The present disclosure is directed generally to wireless communications. Particularly, the present disclosure relates to methods, devices, and systems for hybrid automatic repeat request (HARQ) process mechanism enhancement.

BACKGROUND

Wireless communication technologies are moving the world toward an increasingly connected and networked society. High-speed and low-latency wireless communications rely on efficient network resource management and allocation between user equipment and wireless access network nodes (including but not limited to base stations) . A new generation network is expected to provide high speed, low latency and ultra-reliable communication capabilities and fulfill the requirements from different industries and users.

In some wireless communication systems, there are some limitations on hybrid automatic repeat request (HARQ) processes: for example, a maximum number (X) of uplink (UL) HARQ processes and a maximum number (Y) of downlink (DL) HARQ processes per cell may be supported by a user equipment (UE) . There are some issues/problems with these implementations. In some scenarios, HARQ-acknowledgement (HARQ-ACK) feedback for one cell with higher subcarrier spacing are carried on another cell with lower subcarrier spacing to ensure UL coverage of HARQ-ACK, and the DL or UL HARQ process number may not be enough to achieve the DL or UL peak rate. In some other scenarios, the maximum number of HARQ processes cannot be increased or even is further reduced due to UE capability limitation. As a result, it’s challenging to achieve the peak rate or guarantee the system efficiency in some of these scenarios.

The present disclosure describes various embodiments for HARQ process mechanism enhancement, addressing at least one of the issues/problems discussed in the present disclosure, increasing efficiency of HARQ process, and improving the field of telecommunication.

SUMMARY

This document relates to methods, systems, and devices for wireless communication, and more specifically, for HARQ process mechanism enhancement. The various embodiments in the present disclosure may be beneficial to enhance efficient utilization of HARQ processes, increase the transmission efficiency and speed, and/or boost performance of the wireless communication.

In one embodiment, the present disclosure describes a method for wireless communication, performed by a wireless communication device. The method includes receiving, by a user equipment (UE) , a first physical download shared channel (PDSCH) in a first cell, and determining, by the UE, a hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback for the first PDSCH corresponding to a HARQ process, for transmitting on a second cell.

In one embodiment, the present disclosure describes another method for wireless communication, performed by a wireless communication node. The method includes sending, by a base station, a first physical download shared channel (PDSCH) in a first cell, and receiving, by the base station, a hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback for the first PDSCH corresponding to a HARQ process, via a second cell.

In some other embodiments, an apparatus for wireless communication may include a memory storing instructions and at least one processing circuitry in communication with the memory. When the at least one processing circuitry executes the instructions, the at least one processing circuitry is configured to carry out the above methods.

In some other embodiments, a device for wireless communication may include a memory storing instructions and at least one processing circuitry in communication with the memory. When the at least one processing circuitry executes the instructions, the at least one processing circuitry is configured to carry out the above methods.

In some other embodiments, a computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out the above methods. The computer-readable medium may be a non-transitory computer-readable medium.

The above and other aspects and their implementations are described in greater detail in the drawings, the descriptions, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a wireless communication system include one wireless network node and one or more user equipment.

FIG. 2 shows an example of a network node.

FIG. 3 shows an example of a user equipment.

FIG. 4A shows a flow diagram of a method for wireless communication.

FIG. 4B shows a flow diagram of another method for wireless communication.

FIG. 5 shows a schematic diagram of an embodiment in the present disclosure.

FIG. 6 shows a schematic diagram of another embodiment in the present disclosure.

DETAILED DESCRIPTION

The present disclosure will now be described in detail hereinafter with reference to the accompanied drawings, which form a part of the present disclosure, and which show, by way of illustration, specific examples of embodiments. Please note that the present disclosure may, however, be embodied in a variety of different forms and, therefore, the covered or claimed subject matter is intended to be construed as not being limited to any of the embodiments to be set forth below.

Throughout the specification and claims, terms may have nuanced meanings suggested or implied in context beyond an explicitly stated meaning. Likewise, the phrase “in one embodiment” or “in some embodiments” as used herein does not necessarily refer to the same embodiment and the phrase “in another embodiment” or “in other embodiments” as used herein does not necessarily refer to a different embodiment. The phrase “in one implementation” or “in some implementations” as used herein does not necessarily refer to the same implementation and the phrase “in another implementation” or “in other implementations” as used herein does not necessarily refer to a different implementation. It is intended, for example, that claimed subject matter includes combinations of exemplary embodiments or implementations in whole or in part.

In general, terminology may be understood at least in part from usage in context. For example, terms, such as “and” , “or” , or “and/or, ” as used herein may include a variety of meanings that may depend at least in part upon the context in which such terms are used. Typically, “or” if used to associate a list, such as A, B or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B or C, here used in the exclusive sense. In addition, the term “one or more” or “at least one” as used herein, depending at least in part upon context, may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures or characteristics in a plural sense. Similarly, terms, such as “a” , “an” , or “the” , again, may be understood to convey a singular usage or to convey a plural usage, depending at least in part upon context. In addition, the term “based on” or “determined by” may be understood as not necessarily intended to convey an exclusive set of factors and may, instead, allow for existence of additional factors not necessarily expressly described, again, depending at least in part on context.

The present disclosure describes methods and devices for Hybrid Automatic Repeat Request (HARQ) process mechanism enhancement.

The new generation wireless communication, including the 5th Generation mobile communication technology (5G) or further 6th Generation mobile communication technology (6G) , is expected to face more and more demands. Based on the current development trend, 5G systems are developing supports on features of enhanced mobile broadband (eMBB) , ultra-reliable low-latency communication (URLLC) , and massive machine-type communication (mMTC) . Optionally, artificial intelligence/machine learning (AI/ML) can be used in 5G, 6G or further wireless communication system to improve the efficiency of communication system.

In some implementations, for downlink, a maximum of 16 HARQ processes per cell may be supported by the UE, or subject to UE capability. In some implementations, a maximum of 32 HARQ processes per cell are supported, e.g. non-terrestrial network (NTN) deployment. In some implementations, the number of processes that the UE may assume at most to be used for the downlink is configured to the UE for each cell separately; and when no configuration is provided, the UE may assume a default number of 8 processes.

In some implementations, for uplink, 16 HARQ processes per cell are supported by the UE, or subject to UE capability. In some implementations, a maximum of 32 HARQ processes per cell are supported, e.g. NTN deployment. In some implementations, the number of processes that the UE may assume at most to be used for the uplink is configured to the UE for each cell separately, and when no configuration is provided the UE may assume a default number of 16 processes.

In some implementations, for a deployment scenario with a combination of a frequency range 1 (FR1) time division duplex (TDD) primary cell (PCell) and a frequency range 2 (FR2) TDD secondary cell (SCell) , the DL performance for a cell-edge UE in a FR2 SCell may be impacted by the coverage of the corresponding HARQ-ACK feedback.

In various embodiments, to ensure the UL coverage of HARQ-ACK for a FR2 SCell, one way is to configure only one physical uplink control channel (PUCCH) cell group to allow HARQ-ACK of the FR2 SCell to be transmitted in a PCell, which has more HARQ process numbers (i.e., increasing the maximum number of HARQ processes per cell group) , in order to achieve FR2 DL peak rate. In various embodiments, another way is to implement dynamic switch PUCCH cell or cell group, for allowing HARQ-ACK of the FR2 SCell to be transmitted in PCell or SCell. In some implementations, when the maximum number of HARQ process numbers cannot be increased or even is further reduced due to HARQ buffer limitation, e.g., reduced to 8 HARQ process numbers, at least one of the following schemes may be implemented: the UE being able to receive another one PDSCH or multiple PDSCHs for a given HARQ process until after the end of an expected transmission of HARQ-ACK for that HARQ process, HARQ sharing, and/or increasing transport block (TB) size for transport block on multiple slots (TBoMS) .

FIG. 1 shows a wireless communication system 100 including a wireless network node (or a wireless communication node) 118 and one or more user equipment (UE) (or a wireless communication device or terminal) 110. The wireless network node may include a network base station, which may be a nodeB (NB, e.g., a gNB) in a mobile telecommunications context. Each of the UE may wirelessly communicate with the wireless network node via one or more radio channels 115 for downlink/uplink communication. For example, a first UE 110 may wirelessly communicate with a wireless network node 118 via a channel including a plurality of radio channels during a certain period of time. The network base station 118 may send high layer signaling to the UE 110. The high layer signaling may include configuration information for communication between the UE and the base station. In one implementation, the high layer signaling may include a radio resource control (RRC) message.

FIG. 2 shows an example of electronic device 200 to implement a network base station. The example electronic device 200 may include radio transmitting/receiving (Tx/Rx) circuitry 208 to transmit/receive communication with UEs and/or other base stations. The electronic device 200 may also include network interface circuitry 209 to communicate the base station with other base stations and/or a core network, e.g., optical or wireline interconnects, Ethernet, and/or other data transmission mediums/protocols. The electronic device 200 may optionally include an input/output (I/O) interface 206 to communicate with an operator or the like.

The electronic device 200 may also include system circuitry 204. System circuitry 204 may include processor (s) 221 and/or memory 222. Memory 222 may include an operating system 224, instructions 226, and parameters 228. Instructions 226 may be configured for the one or more of the processors 124 to perform the functions of the network node. The parameters 228 may include parameters to support execution of the instructions 226. For example, parameters may include network protocol settings, bandwidth parameters, radio frequency mapping assignments, and/or other parameters.

FIG. 3 shows an example of an electronic device to implement a terminal device 300 (for example, user equipment (UE) ) . The UE 300 may be a mobile device, for example, a smart phone or a mobile communication module disposed in a vehicle. The UE 300 may include communication interfaces 302, a system circuitry 304, an input/output interfaces (I/O) 306, a display circuitry 308, and a storage 309. The display circuitry may include a user interface 310. The system circuitry 304 may include any combination of hardware, software, firmware, or other logic/circuitry. The system circuitry 304 may be implemented, for example, with one or more systems on a chip (SoC) , application specific integrated circuits (ASIC) , discrete analog and digital circuits, and other circuitry. The system circuitry 304 may be a part of the implementation of any desired functionality in the UE 300. In that regard, the system circuitry 304 may include logic that facilitates, as examples, decoding and playing music and video, e.g., MP3, MP4, MPEG, AVI, FLAC, AC3, or WAV decoding and playback; running applications; accepting user inputs; saving and retrieving application data; establishing, maintaining, and terminating cellular phone calls or data connections for, as one example, internet connectivity; establishing, maintaining, and terminating wireless network connections, Bluetooth connections, or other connections; and displaying relevant information on the user interface 310. The user interface 310 and the inputs/output (I/O) interfaces 306 may include a graphical user interface, touch sensitive display, haptic feedback or other haptic output, voice or facial recognition inputs, buttons, switches, speakers and other user interface elements. Additional examples of the I/O interfaces 306 may include microphones, video and still image cameras, temperature sensors, vibration sensors, rotation and orientation sensors, headset and microphone input /output jacks, Universal Serial Bus (USB) connectors, memory card slots, radiation sensors (e.g., IR sensors) , and other types of inputs.

Referring to FIG. 3, the communication interfaces 302 may include a Radio Frequency (RF) transmit (Tx) and receive (Rx) circuitry 316 which handles transmission and reception of signals through one or more antennas 314. The communication interface 302 may include one or more transceivers. The transceivers may be wireless transceivers that include modulation /demodulation circuitry, digital to analog converters (DACs) , shaping tables, analog to digital converters (ADCs) , filters, waveform shapers, filters, pre-amplifiers, power amplifiers and/or other logic for transmitting and receiving through one or more antennas, or (for some devices) through a physical (e.g., wireline) medium. The transmitted and received signals may adhere to any of a diverse array of formats, protocols, modulations (e.g., QPSK, 16-QAM, 64-QAM, or 256-QAM) , frequency channels, bit rates, and encodings. As one specific example, the communication interfaces 302 may include transceivers that support transmission and reception under the 2G, 3G, BT, WiFi, Universal Mobile Telecommunications System (UMTS) , High Speed Packet Access (HSPA) +, 4G /Long Term Evolution (LTE) , 5G standards, 6G, and/or any further generation standards. The techniques described below, however, are applicable to other wireless communications technologies whether arising from the 3rd Generation Partnership Project (3GPP) , GSM Association, 3GPP2, IEEE, or other partnerships or standards bodies.

Referring to FIG. 3, the system circuitry 304 may include one or more processors 321 and memories 322. The memory 322 stores, for example, an operating system 324, instructions 326, and parameters 328. The processor 321 is configured to execute the instructions 326 to carry out desired functionality for the UE 300. The parameters 328 may provide and specify configuration and operating options for the instructions 326. The memory 322 may also store any BT, WiFi, 3G, 4G, 5G, 6G, or other data that the UE 300 may send, or has received, through the communication interfaces 302. In various implementations, a system power for the UE 300 may be supplied by a power storage device, such as a battery or a transformer.

The present disclosure describes various embodiment for HARQ process mechanism enhancement, which may be implemented, partly or totally, by the network base station and/or the user equipment described above in FIGs. 2-3. The various embodiments in the present disclosure may enable efficient wireless transmission in the telecommunication system, which may increase the resource utilization efficiency and/or boost wireless communication performance.

Referring to FIG. 4A, the present disclosure describes various embodiments of a method 400 for wireless communication. The method 400 may be performed by a wireless communication device (e.g., a user equipment) . The method 400 may include a portion or all of the following steps: step 410, receiving, by a user equipment (UE) , a first physical download shared channel (PDSCH) in a first cell, and/or step 420, determining, by the UE, a hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback for the first PDSCH corresponding to a HARQ process, for transmitting on a second cell.

Referring to FIG. 4B, the present disclosure describes various embodiments of a method 450 for wireless communication. The method 450 may be performed by a wireless communication node (e.g., a base station or a radio access network (RAN) ) . The method 450 may include a portion or all of the following steps: step 460, sending, by a base station, a first physical download shared channel (PDSCH) in a first cell, and/or step 470, receiving, by the base station, a hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback for the first PDSCH corresponding to a HARQ process, via a second cell.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, the first cell and the second cell are different cells, the HARQ-ACK feedback is transmitted in the second cell which is a primary cell (PCell) , and the first PDSCH is transmitted in the first cell which is a secondary cell (SCell) ; or the first cell and the second cell are a same cell.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, after receiving the first PDSCH corresponding to the HARQ process, the UE receives one or more second PDSCHs corresponding to the same HARQ process before an expected transmission of the HARQ-ACK feedback for the HARQ process.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, a maximum number of PDSCHs corresponding to the same HARQ process is predefined or configured, wherein the PDSCHs comprises the first PDSCH and the one or more second PDSCHs.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, the maximum number of PDSCHs corresponding to the same HARQ process is determined to be inversely proportional to the maximum number of HARQ processes.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, a time duration is added to a PDSCH processing time; a time interval between consecutive PDSCHs corresponding to the same HARQ process is predefined or configured; and/or the UE’s receiving one or more second PDSCHs corresponding to the same HARQ process before the expected transmission of the HARQ-ACK feedback for the HARQ process is enabled or disabled dynamically or semi-statically.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, the HARQ-ACK feedback is transmitted based on either a single physical uplink control channel (PUCCH) cell group or two PUCCH cell groups.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, the HARQ-ACK feedback is transmitted based on two PUCCH cell groups, and the HARQ-ACK feedback is reported cross the two PUCCH cell groups.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, a time duration is added to a PDSCH processing time; HARQ-ACK codebooks of the two PUCCH cell groups are appended, wherein the HARQ-ACK codebooks have same or different codebook types; PUCCH resource for transmitting the HARQ-ACK feedback is determined by the PUCCH cell group that is applied; and/or a PUCCH cell group or PUCCH resource in which the PUCCH cell group for transmitting the HARQ-ACK feedback is indicated by a downlink control information (DCI) .

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, switching between the single PUCCH cell group and the two PUCCH cell groups is indicated by a DCI or a medium access control (MAC) control element (CE) .

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, all cells in the two PUCCH cell groups are comprised in the single PUCCH cell group; and/or the switching between the single PUCCH cell group and the two PUCCH cell groups is performed by enabling or disabling PUCCH SCell or one of the two PUCCH cell groups.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, a transport block (TB) size of a TB which is carried on the first PDSCH on multiple slots is increased.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, a total number of resource elements (REs) in the TB is determined by one slot combined with a scaling factor, wherein the scaling factor is equal to or larger than 1; and/or a time duration is added to a PDSCH processing time.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, HARQ process sharing is performed between downlink (DL) HARQ processes and uplink (UL) HARQ processes.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, a number of the DL HARQ processes increases by sharing from the UL HARQ processes; a number of the UL HARQ processes increases by sharing from the DL HARQ processes; and/or the HARQ process sharing is determined based on a DL and UL proportion within a frame structure.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, a total number of DL HARQ processes and UL HARQ processes is maintained as a predefined number; and/or a number of DL HARQ processes and a number of UL HARQ processes is proportional to DL slots and UL slots in a frame structure.

In some implementations, optionally or additional to any one or any combinations of more than one implementations or embodiments in the present disclosure, a total number of DL HARQ processes and UL HARQ processes is maintained dynamically as a predefined number; and/or a number of DL HARQ processes and a number of UL HARQ processes is determined according to a first shared HARQ process number and a second shared HARQ process number, wherein the first shared HARQ process number is from the UL processes to the DL processes, and the second shared HARQ process number is from the DL processes to the UL processes.

The present disclosure describes various exemplary embodiments for HARQ process mechanism enhancement in a wireless communication system, and the exemplary embodiments merely serve as examples and do not pose limitations. Any steps and/or operations in one same embodiment/implementation or more than one different embodiments/implementation in the present disclosure may be combined or arranged in any amount or order, as desired. Two or more of the steps and/or operations may be performed in parallel. Embodiments and implementations in the disclosure may be used separately or combined in any order. Further, each of the methods (or embodiments) may be implemented by processing circuitry (e.g., one or more processors or one or more integrated circuits) .

Embodiment Set I

The present disclosure describes various embodiments for enhancing HARQ process mechanism. For a deployment scenario with frequency range 1 (FR1) TDD PCell + frequency range 2 (FR2) TDD SCell, the DL performance for a cell-edge UE in a FR2 SCell may be impacted by the coverage of the corresponding HARQ-ACK feedback. To ensure the UL coverage of HARQ-ACK for a FR2 SCell, one way is to configure only one PUCCH cell group to allow HARQ-ACK of the FR2 SCell to be transmitted in a PCell.

In some implementations, in the context of this deployment scenario, a sufficient number of HARQ processes may be used based on the following scheduling restriction: the UE is not expected to receive another PDSCH for a given HARQ process until after the end of an expected transmission of HARQ-ACK for that HARQ process.

In some implementations, when only a maximum of 16 HARQ process numbers is supported, the FR2 DL peak rate for a UE may be reduced. In the above scenarios, only the HARQ-ACK feedback latency is considered. However, the round trip time (RTT) also includes the additional processing time at the network (e.g., gNB) side between HARQ-ACK feedback and another PDSCH transmission. The additional processing time may include PUCCH processing time and other latency (e.g., interaction latency between different cells) . Therefore, more HARQ process numbers are actually needed in above scenarios.

In some implementations, additionally, when the maximum number of HARQ process numbers cannot be increased or even is further reduced due to HARQ buffer limitation, e.g. 8 HARQ process numbers, the following scheme may be applied. Referring to FIG. 5, the UE may receive another one or multiple PDSCHs for a given HARQ process before the expected transmission of HARQ-ACK for that HARQ process (or before the end or start of the expected transmission of HARQ-ACK for that HARQ process) . In some implementations, the last PDSCH with NACK feedback may be re-transmitted for the given HARQ process. In some implementations, any redundancy version (e.g. RV0, RV1, RV2, RV3) or only some of the redundancy versions (e.g. only RV0 or RV3) may be used for the re-transmitted PDSCH.

For a non-limiting example referring to FIG. 5, the same HARQ process number P1 (P1 is an integer, e.g. P1=1) is used for both PDSCH1 and PDSCH2. Additionally, PDSCH2, which is after PDSCH1, may be transmitted before the end or start of the HARQ-ACK feedback for that HARQ process. When the HARQ-ACK feedback for PDSCH1 and PDSCH2 are {ACK, ACK} , no re-transmission is needed. When the HARQ-ACK feedback for PDSCH1 and PDSCH2 are {ACK, NACK} , a re-transmission is performed for PDSCH2. When the HARQ-ACK feedback for PDSCH1 and PDSCH2 are {NACK, ACK} , a re-transmission is performed for PDSCH1. In some of these implementations, RV 0 or RV3 may be used for the re-transmission. When the HARQ-ACK feedback for PDSCH1 and PDSCH2 are {NACK, NACK} , a re-transmission is performed for PDSCH2.

In some embodiments, at least one of following rules may be applied for the scheme, that is, the UE may receive another one or multiple PDSCHs for a given HARQ process before the end or start of the expected transmission of HARQ-ACK for that HARQ process.

In some implementations with same HARQ process corresponding to multiple PDSCHs, a maximum number of PDSCHs per HARQ process number is a predefined value, or a configured value. In some implementations, the maximum number of PDSCHs per HARQ process is determined by the maximum number of HARQ processes, e.g. a maximum number of PDSCHs per HARQ process is inversely proportional to the maximum number of HARQ processes. For example, the maximum number of PDSCHs per HARQ process is predefined or configured by higher layer parameter, e.g. 2, 4, or 8, etc. For example, the maximum number of PDSCHs per HARQ process is 2 when the maximum number of HARQ processes is N; the maximum number of PDSCHs per HARQ process is 4 when the maximum number of HARQ processes is M, wherein M = N/2. E. g. N=16, M=8.

In some implementations, additional time for PDSCH processing time is added when same HARQ corresponds to multiple PDSCHs. The additional time may be one or multiple symbols, or some milliseconds/microseconds/nanoseconds depending on UE capability. For example, when the first uplink symbol of the PUCCH which carries the HARQ-ACK information, as defined by the assigned HARQ-ACK timing K₁ and K_offset, if configured, and the PUCCH resource to be used and including the effect of the timing advance, starts no earlier than at symbol L₁, where L₁ is defined as the next uplink symbol with its CP starting after T_proc, 1= (N₁+d_1, 1+d₂+d₃) (2048+144) ·κ2^-μ·T_C+T_ext after the end of the last symbol of the PDSCH carrying the TB being acknowledged, then the UE shall provide a valid HARQ-ACK message. For a PDSCH with disabled HARQ-ACK feedback, T_proc, 1= (N₁+d_1, 1+d₂) (2048+144) ·κ2^-μ·T_C+T_ext. For same HARQ with multiple PDSCHs, T_proc, 1= (N₁+d_1, 1+d₂+d₃+d₄) (2048+144) ·κ2^-μ·T_C+T_ext. wherein, d₄ is the additional time for PDSCH processing time in case of same HARQ with multiple PDSCHs. N₁ is based on μ of predefined number of symbols for UE processing capability 1 and 2 respectively, where μ corresponds to the one of (μ_PDCCH, μ_PDSCH, μ_UL) resulting with the largest T_proc, 1, where the μ_PDCCH corresponds to the subcarrier spacing of the PDCCH scheduling the PDSCH, the μ_PDSCH corresponds to the subcarrier spacing of the scheduled PDSCH, and μ_UL corresponds to the subcarrier spacing of the uplink channel with which the HARQ-ACK is assumed to be transmitted for PDSCH with or without disabled HARQ-ACK feedback, and κ is defined as κ=T_s/T_c=64 where T_s=1/ (Δf_ref·N_f, ref) , Δf_ref=15·10³ Hz and N_f, ref=2048. T_c=1/ (Δf_max·N_f) where Δf_max=480·10³ Hz and N_f=4096. For the PDSCH mapping type A, when the last symbol of PDSCH is on the i-th symbol of the slot where i < 7, then d_1, 1 = 7 -i. When a PUCCH of a larger priority index would overlap with a PUCCH of a smaller priority index, d₂ for the PUCCH of a larger priority is set as reported by the UE. When the UE is configured with higher layer parameter dmrs-TypeEnh, the additional processing delay d₃ may be applied. For operation with shared spectrum channel access in FR1, T_extmay be applied.

In some implementations, a gap or minimum time offset between two PDSCHs with same HARQ processing number is introduced or defined in case of same HARQ with multiple PDSCHs. For example, due to flush HARQ buffer, the gap or minimum time offset between two consecutive PDSCHs is needed for gNB or UE processing. For example, the gap or minimum time offset may be some symbols, optionally depending on UE capability or indicated by DCI or MAC CE.

In some implementations, dynamic or semi-static enable/disable scheduling restriction may be implemented, optionally indicated by DCI, MAC CE or RRC, wherein the scheduling restriction refers to the UE’s receiving one or more second PDSCHs corresponding to the same HARQ process before the expected transmission of the HARQ-ACK feedback for the HARQ process. When disabling the scheduling restriction, same HARQ with multiple PDSCHs can be supported: the UE may receive another one or multiple PDSCHs for a given HARQ process before the end or start of the expected transmission of HARQ-ACK for that HARQ process. When enabling the scheduling restriction, same HARQ with multiple PDSCHs cannot be supported: the UE is not expected to receive another PDSCH for a given HARQ process until after the end of an expected transmission of HARQ-ACK for that HARQ process. Optionally, the default mode/capability is the enabled scheduling restriction; and/or enabling or disabling the scheduling restriction may depend on UE location within a cell, and/or channel signal quality.

Various embodiments described in the present disclosure may have the following benefits: in some scenarios, when the maximum number of HARQ processes cannot be increased or even is further reduced due to UE capability limitation, the peak rate or system efficiency can be guaranteed with HARQ process mechanism enhancements on same HARQ with multiple PDSCHs supported, and with the rules in the embodiment, the same HARQ with multiple PDSCHs can be applied for gNB or UE considering actual implementation.

Embodiment Set II

The present disclosure describes various embodiments for enhancing HARQ process mechanism. For dynamic switch PUCCH cell or PUCCH cell group, HARQ-ACK of the FR2 SCell may be transmitted in PCell or SCell.

In some implementations, compared with HARQ process number (HPN) increase based on single PUCCH group, the following PUCCH switching may be considered. For example as shown in FIG. 6, when the UE is located in FR2 SCell center, two PUCCH cell groups are applied and HARQ-ACK feedback for PDSCH on FR2 SCell can be carried by PUCCH on SCell; when the UE is located in FR2 SCell edge, single PUCCH cell group is applied and HARQ-ACK feedback for PDSCH on FR2 SCell can be carried by PUCCH on PCell. That is, dynamic switching between single PUCCH cell group and two PUCCH cell groups can be applied for a UE.

In some implementations, for the details of dynamic PUCCH cell group switching, one of following schemes can be applied.

For one scheme (Scheme 1) , HARQ-ACK reporting may be cross PUCCH cell group. That is, the HARQ-ACK generation is still performed on each PUCCH cell group, and appending the HARQ-ACK codebook (s) of one PUCCH cell group to the HARQ-ACK codebook of the other PUCCH cell group. In another words, two PUCCH cell groups are configured and the HARQ-ACK reporting cross PUCCH cell group can be supported.

In some implementations, additional process time can be applied. For example, additional time for PDSCH processing time is added when HARQ-ACK reporting cross PUCCH cell group. The additional time may be one or multiple symbols, or some milliseconds, microseconds, or nanoseconds, depending on UE capability. For example, when the first uplink symbol of the PUCCH which carries the HARQ-ACK information, as defined by the assigned HARQ-ACK timing K₁ and K_offset, when configured, and the PUCCH resource to be used and including the effect of the timing advance, starts no earlier than at symbol L₁, where L₁ is defined as the next uplink symbol with its CP starting after T_proc, 1= (N₁+d_1, 1+d₂+d₃) (2048+144) ·κ2^-μ·T_C+T_ext after the end of the last symbol of the PDSCH carrying the TB being acknowledged, then the UE shall provide a valid HARQ-ACK message. For a PDSCH with disabled HARQ-ACK feedback, T_proc, 1= (N₁+d_1, 1+d₂) (2048+144) ·κ2^-μ·T_C+T_ext. For HARQ-ACK reporting cross PUCCH cell group, T_proc, 1= (N₁+d_1, 1+d₂+d₃+d₄) (2048+144) ·κ2^-μ·T_C+T_ext. wherein, d₄ is the additional time for PDSCH processing time in case of HARQ-ACK reporting cross PUCCH cell group. N₁ is based on μ of predefined number of symbols for UE processing capability 1 and 2 respectively, where μ corresponds to the one of (μ_PDCCH, μ_PDSCH, μ_UL) resulting with the largest T_proc, 1, where the μ_PDCCH corresponds to the subcarrier spacing of the PDCCH scheduling the PDSCH, the μ_PDSCH corresponds to the subcarrier spacing of the scheduled PDSCH, and μ_UL corresponds to the subcarrier spacing of the uplink channel with which the HARQ-ACK is assumed to be transmitted for PDSCH with or without disabled HARQ-ACK feedback, and κ is defined as κ=T_s/T_c=64 where T_s=1/ (Δf_ref·N_f, ref) , Δf_ref=15·10³ Hz and N_f, ref=2048. T_c=1/ (Δf_max·N_f) where Δf_max=480·10³ Hz and N_f=4096. For the PDSCH mapping type A, when the last symbol of PDSCH is on the i-th symbol of the slot where i < 7, d_1, 1 = 7 -i. When a PUCCH of a larger priority index would overlap with a PUCCH of a smaller priority index, d₂ for the PUCCH of a larger priority is set as reported by the UE. When the UE is configured with higher layer parameter dmrs-TypeEnh, the additional processing delay d₃ may be applied. For operation with shared spectrum channel access in FR1, T_extmay be applied.

In some implementations, the HARQ-ACK codebook (s) of the second PUCCH group are appended to the HARQ-ACK codebook of the first PUCCH group, which may have same or different codebook type. For example, appending 4 codebooks of 4 FR2 120khz slots to 1 codebook of 1 FR1 30khz slot. Codebook type may comprise type1 codebook which is semi-static codebook, type 2 codebook which is dynamic codebook, and/or type 3 codebook which is HARQ-ACK feedback for all/partial HPN.

In some implementations, PUCCH resource is determined by the PUCCH cell group applied. A PUCCH cell group or PUCCH resource in which the PUCCH cell group for transmitting the HARQ-ACK feedback is indicated by a downlink control information (DCI) . For example, in case there are overlapped PUCCH in the first PUCCH cell group, the codebook of the first PUCCH cell group is appended with the codebook (s) of the second PUCCH cell group, and carried on the PUCCH. In case there are no overlapped PUCCH in the first PUCCH cell group, the codebook (s) of the second PUCCH cell group is carried on a PUCCH in the first PUCCH cell group, wherein, the PUCCH resource indicator (PRI) is applied for the PUCCH in the first PUCCH cell group. Optionally, the PRI is applied for the PUCCH resource in the first or second PUCCH cell group is determined by an independent DCI field.

Another scheme (Scheme 2) includes switching between single PUCCH cell group and two PUCCH cell groups. Using a downlink control information (DCI) or medium access control (MAC) control element (CE) to achieve the switching between single PUCCH cell group and two PUCCH cell groups. For example as shown in FIG. 6, one or two PUCCH cell groups can be dynamically switched by a DCI or MAC CE. Optionally, the cells that belong to the two PUCCH cell groups are all comprised in the single PUCCH cell group.

In some implementations, additional process time can be applied. For example, additional time for PUCCH cell group switching time is applied when switching between single PUCCH cell group and two PUCCH cell groups. Additional time for PDSCH processing time is added when switching between single PUCCH cell group and two PUCCH cell groups. The additional time may be one or multiple symbols, or some milliseconds/microseconds/nanoseconds depending on UE capability. For example, when the first uplink symbol of the PUCCH which carries the HARQ-ACK information, as defined by the assigned HARQ-ACK timing K₁ and K_offset, when configured, and the PUCCH resource to be used and including the effect of the timing advance, starts no earlier than at symbol L₁, where L₁ is defined as the next uplink symbol with its CP starting after T_proc, 1= (N₁+d_1, 1+d₂+d₃) (2048+144) ·κ2^-μ·T_C+T_ext after the end of the last symbol of the PDSCH carrying the TB being acknowledged, then the UE shall provide a valid HARQ-ACK message. For a PDSCH with disabled HARQ-ACK feedback, T_proc, 1= (N₁+d_1, 1+d₂) (2048+144) ·κ2^-μ·T_C+T_ext. For switching between single PUCCH cell group and two PUCCH cell groups, T_proc, 1= (N₁+d_1, 1+d₂+d₃+d₄) (2048+144) ·κ2^-μ·T_C+T_ext. wherein, d₄ is the additional time for PDSCH processing time in case of switching between single PUCCH cell group and two PUCCH cell groups.

In some implementations, PUCCH cell group switching can be achieved by dynamically enabling and/or disabling PUCCH SCell, optionally indicated by DCI or MAC CE. For example, PUCCH SCell is configured in a cell group, a first set of cells which the HARQ-ACK feedback is transmitted on the PCell is the first PUCCH cell group, a second set of cells which the HARQ-ACK feedback is transmitted on the PUCCH SCell is the second PUCCH cell group. For switching between single PUCCH cell group and two PUCCH cell groups, single PUCCH cell group is switched to when the PUCCH SCell is disabled, and/or two PUCCH cell groups is switched to when the PUCCH SCell is enabled/configured.

In some implementations, the HARQ-ACK information during or after the PUCCH cell group switching is skipped or generated with NACK bit. For example, when a PDCCH monitoring occasion that provides a DCI is before PUCCH cell group switching, and the PUCCH indicated by the DCI is to be transmitted after the PUCCH cell group switching, the corresponding HARQ-ACK information for the DCI is skipped or generated with NACK bit.

Various embodiments described in the present disclosure may have the following benefits: in some scenarios, when the maximum number of HARQ processes cannot be increased or even is further reduced due to UE capability limitation, the peak rate or system efficiency can be guaranteed with HARQ process mechanism enhancements on PUCCH cell group switching, and with the schemes in the embodiment, the HARQ-ACK feedback transmitted one different PUCCH cell groups dynamically can be applied for gNB or UE considering actual implementation.

Embodiment Set III

The present disclosure describes various embodiments for enhancing HARQ process mechanism. For a deployment scenario with frequency range 1 (FR1) TDD PCell + frequency range 2 (FR2) TDD SCell, the DL performance for a cell-edge UE in a FR2 SCell may be impacted by the coverage of the corresponding HARQ-ACK feedback. To ensure the UL coverage of HARQ-ACK for a FR2 SCell, one way is to configure only one PUCCH cell group to allow HARQ-ACK of the FR2 SCell to be transmitted in a PCell. In the context of this deployment scenario, a sufficient number of HARQ process numbers may be used based on the following scheduling restriction: the UE is not expected to receive another PDSCH for a given HARQ process until after the end of an expected transmission of HARQ-ACK for that HARQ process.

In some implementations, when the maximum number of HARQ process numbers cannot be increased or even is further reduced due to HARQ buffer limitation, e.g. 8 HARQ process numbers, the following scheme may be applied. That is, one TB on multiple slot can be applied which less HPN is applied. While, in order to guarantee FR2 DL peak rate, one TB on multiple slot with TB size increase can be applied.

In other words, in case DL HARQ processes is not enough or even is further reduced due to HARQ buffer limitation, e.g. 8 HARQ process numbers, and both FR2 DL peak rate and coverage performance should be guaranteed, one TB on multiple slot can be applied with increased TB size (TBS) .

In some implementations, increased TBS for TBoMS can be determined by at least one of the following methods.

One method (Alt. 1) includes a total number of resource elements (REs) in the TB, N_RE, being determined by N slots *N_RE in one slot (like TBoMS) , optionally combined with a scaling factor S of N_info which is no larger than 1, e.g., 1, 0.8, 0.5, and etc.

Another method (Alt. 2) includes N_RE being determined by one slot (like repetition) , optionally combined with a scaling factor S of N_info which is no less than 1, e.g., 1, 1.5, 2, 4, and etc.

Another method (Alt. 3) includes N_RE being determined byoptionally combined with a scaling factor S of N_info which is no larger than 1.

In some implementations, the number of slots or the scaling factor S introduced for TBS increase can be determined by explicitly configuration, or determined by the proportion of reduced HARQ processes. For example, in case 16 HPN is reduced to 8 HPN, then N slots = 2 slots. For example, in case 16 HPN is reduced to 8 HPN, the scaling factor S could be 2 or 1.5 based on above Alt. 2.

In some implementations, additional process time can be applied. For example, additional time for PDSCH processing time is added in case of TBoMS carried on the PDSCH. The additional time may be one or multiple symbols, or some milliseconds/microseconds/nanoseconds depended on UE capability. For example, when the first uplink symbol of the PUCCH which carries the HARQ-ACK information, as defined by the assigned HARQ-ACK timing K₁ and K_offset, when configured, and the PUCCH resource to be used and including the effect of the timing advance, starts no earlier than at symbol L₁, where L₁ is defined as the next uplink symbol with its CP starting after T_proc, 1= (N₁+d_1, 1+d₂+d₃) (2048+144) ·κ2^-μ·T_C+T_ext after the end of the last symbol of the PDSCH carrying the TB being acknowledged, then the UE shall provide a valid HARQ-ACK message. For a PDSCH with disabled HARQ-ACK feedback, T_proc, 1= (N₁+d_1, 1+d₂) (2048+144) ·κ2^-μ·T_C+T_ext. For HARQ-ACK reporting cross PUCCH cell group, T_proc, 1= (N₁+d_1, 1+d₂+d₃+d₄) (2048+144) ·κ2^-μ·T_C+T_ext. wherein, d₄ is the additional time for PDSCH processing time in case of TBoMS carried on the PDSCH. N₁ is based on μ of predefined number of symbols for UE processing capability 1 and 2 respectively, where μcorresponds to the one of (μ_PDCCH, μ_PDSCH, μ_UL) resulting with the largest T_proc, 1, where the μ_PDCCH corresponds to the subcarrier spacing of the PDCCH scheduling the PDSCH, the μ_PDSCH corresponds to the subcarrier spacing of the scheduled PDSCH, and μ_UL corresponds to the subcarrier spacing of the uplink channel with which the HARQ-ACK is assumed to be transmitted for PDSCH with or without disabled HARQ-ACK feedback, and κ is defined as κ=T_s/T_c=64 where T_s=1/ (Δf_ref·N_f, ref) , Δf_ref=15·10³ Hz and N_f, ref=2048. T_c=1/ (Δf_max·N_f) where Δf_max= 480·10³ Hz and N_f=4096. For the PDSCH mapping type A, when the last symbol of PDSCH is on the i-th symbol of the slot where i < 7, then d_1, 1 = 7 -i. When a PUCCH of a larger priority index would overlap with a PUCCH of a smaller priority index, d₂ for the PUCCH of a larger priority is set as reported by the UE. When the UE is configured with higher layer parameter dmrs-TypeEnh, the additional processing delay d₃ may be applied. For operation with shared spectrum channel access in FR1, T_extmay be applied.

In some implementations, for PDSCH reception with TBoMS ending in DL slot n_D, the UE transmits the PUCCH in UL slot n+k where k is provided by the PDSCH-to-HARQ_feedback timing indicator field, when present, in a DCI format scheduling the TBoMS PDSCH reception. Wherein n is the last UL slot for PUCCH transmission that overlaps with the DL slot n_D for the TBoMS PDSCH reception.

In some implementations, for type 1 codebook for PDSCH reception with TBoMS ending in DL slot n_D, UE reports HARQ-ACK information for a PDSCH reception from DL slot to DL slot n_D; wherein, slots in case TBoMS without repetition configured, and M is the number of slots used for TBoMS; slots in case TBoMS with repetition configured, and M is the number of slots used for TBoMS, N is the number of slots for repetition. In some implementations, for type 1 codebook generation, usingto justify whether there is valid PDSCH. Whereinis a maximum value ofFor example, for each slot from slotto slot n_0, k+n_D, at least one symbol of the PDSCH time resource derived by row r is configured as UL by tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated where K_1, k is the k-th slot timing value in set K₁, where n_0, k is a DL slot with a smallest index among DL slots overlapping with UL slot n_U-K_1, k.

Various embodiments described in the present disclosure may have the following benefits: in some scenarios, when the maximum number of HARQ processes cannot be increased or even is further reduced due to UE capability limitation, the peak rate or system efficiency can be guaranteed with HARQ process mechanism enhancements on TB on multiple slots with TB size increase, and with the schemes in the embodiment, the HARQ-ACK feedback transmitted one different PUCCH cell groups dynamically can be applied for gNB or UE considering actual implementation.

Embodiment Set IV

The present disclosure describes various embodiments for enhancing HARQ process mechanism. In some implementations, the time domain resource is split between downlink and uplink in TDD, wherein the downlink resources and uplink resources may not be symmetric.

For FR2 TDD SCell, typical TDD frame structure is a single period with “DDDSU” for consecutive 5 slots, wherein “D” refers to downlink slot, “U” refers to uplink slot, and “S” refers to flexible slot that may comprise at least one of D symbol (s) and U symbol (s) . For one example (example #1) , when both DL and UL traffic are scheduled, 16 UL HARQ processes are redundant. Based on PUSCH preparation time for PUSCH timing capability 1, two UL HARQ processes may be enough. As a result, 14 UL HARQ processes can be shared for DL HARQ processes. For another example (example #2) , when only DL traffic are scheduled, or optionally the frame structure of the cell is configured with a single period with “DDDDD” for consecutive 5 slots, 16 UL HARQ processes are useless. As a result, 16 UL HARQ processes can be shared for DL HARQ processes.

That is, the number of DL HARQ processes can be increased based on sharing from at least one of UL HARQ processes, or the number of UL HARQ processes can be increased based on sharing from at least one of DL HARQ processes. As a result, when the maximum number of HARQ processes cannot be increased or even is further reduced due to HARQ buffer limitation, e.g. 8 HARQ processes, the HARQ processes sharing may be applied. That is, both FR2 DL peak rate and coverage performance can be guaranteed.

In some implementations, the HARQ processes sharing can be determined on D/U proportion based on frame structure. For example, based on above example #2, all of the UL HARQ processes can be shared to DL HARQ processes.

Various embodiments described in the present disclosure may have the following benefits: in some scenarios, when the maximum number of HARQ processes cannot be increased or even is further reduced due to UE capability limitation, the peak rate or system efficiency can be guaranteed with HARQ process mechanism enhancements on HARQ processes sharing, and with the schemes in the embodiment, the UL HARQ processes shared for DL HARQ processes can be applied for gNB or UE considering actual implementation.

Embodiment Set V

The present disclosure describes various embodiments for enhancing HARQ process mechanism. For HARQ processes sharing, the number of DL HARQ processes can be increased based on sharing from UL HARQ processes, or the number of UL HARQ processes can be increased based on sharing from DL HARQ processes. As a result, if the maximum number of HARQ process numbers cannot be increased or even is further reduced due to HARQ buffer limitation, e.g. 8 HARQ processes, the HARQ processes sharing may be applied. Another way is to increase the HARQ process numbers. For example, when the maximal supported HARQ process number is X for UL and Y for DL, candidate component values for (X, Y) may comprise { (16, 32) , (32, 16) , (32, 32) } . In some implementations, semi-static HARQ sharing can be achieved by increasing DL (UL) HARQ process number combined with decreasing UL (DL) HARQ process number, within a total HARQ process number. In some implementations, X+Y = Z, 0≤X≤Z, 0≤ Y≤Z, that is without total HARQ process Z increase, increase DL (UL) HARQ process number Y (X) combined with UL (DL) HARQ process number X (Y) decrease.

In some implementations, within a total HARQ process number Z unchanged, which could be an integer, e.g. Z=16, 32, 64, etc, DL (UL) HARQ process number can be increased combined with UL (DL) HARQ process number decrease. For example, Z=32, UE could report asymmetric and/or be configured with asymmetric (X, Y) , for example, (X, Y) may be one of the following: (16, 16) , (8, 24) , (0, 32) , (24, 8) , or (32, 0) .

In some implementations, the reported/configured (X, Y) could be determined by D/U proportion based on frame structure. For example, when only DL traffic are scheduled, or optionally the frame structure of the cell is configured with a single period with “DDDDD” for consecutive 5 slots, 16 UL HARQ processes are useless, all of the UL HARQ processes can be shared with DL HARQ processes, e.g. (X, Y) = (0, 32) . In some implementations, when (X, Y) is not reported by a UE, or only (X, Y) = (16, 16) is reported, the semi-static HARQ sharing is not supported.

In some implementations, a total HARQ process number Z increased, wherein Z could be an integer, e.g. Z=16, 32, 64, etc, and DL (UL) HARQ process number can be increased combined with UL (DL) HARQ process number decrease. For example, 32≤Z≤64, the UE could report asymmetric and/or be configured with asymmetric (X, Y) , e.g., (X, Y) could be (16, 16) , (8, 32) , (16, 32) , (32, 8) , or (32, 16) .

In some implementations, HARQ sharing could be achieved by α*X+β*Y ≤ Z. wherein the scaling factor α, β can be predefined or configured, optionally may comprise at least one of {0, 0.1, 0.2, 0.4, 0.5, 0.6, 0.8, 1, 1.2, 1.5, 2, 4, 6, 8} .

In some implementations, (X, Y) could be UL HARQ process number and DL HARQ process number for one cell, a cell group, a band or a UE; or UL HARQ process numbers for different cells, cell groups or bands, or DL HARQ process numbers for different cells, cell groups or bands, e.g. for two cells of PCell and one SCell.

Various embodiments described in the present disclosure may have the following benefits: in some scenarios, when the maximum number of HARQ processes cannot be increased or even is further reduced due to UE capability limitation, the peak rate or system efficiency can be guaranteed with HARQ process mechanism enhancements on HARQ processes sharing, and with the schemes in the embodiment, the semi-static HARQ sharing can be applied for gNB or UE considering actual implementation.

Embodiment Set VI

The present disclosure describes various embodiments for enhancing HARQ process mechanism. For HARQ processes sharing, DL HARQ processes can be increased based on sharing from UL HARQ processes, or UL HARQ processes can be increased based on sharing from DL HARQ processes. As a result, when the maximum number of HARQ process numbers cannot be increased or even is further reduced due to HARQ buffer limitation, e.g. 8 HARQ processes, the HARQ processes sharing may be applied. In some implementations, another way is to increase the HARQ process numbers. For example, the maximal supported HARQ process number is X for UL and Y for DL. Candidate component values for (X, Y) may comprise { (16, 32) , (32, 16) , (32, 32) } .

In some implementations with dynamic HARQ sharing, DL (UL) HARQ process number may be increased with being combined with UL (DL) HARQ process number decrease, within a total HARQ process number. Assume X+Y = Z before HARQ sharing, X1+Y1 =Z after HARQ sharing, wherein X-Z1≤X1≤X+Z2, Y-Z2≤Y1≤Y+Z1, the shared HARQ process number is Z1 from UL for DL, and/or Z2 from DL for UL. In some implementations, without total HARQ process Z increase, increase DL (UL) HARQ process number Y (X) combined with UL (DL) HARQ process number X (Y) decrease.

In some implementations, a total HARQ process number Z may be unchanged, wherein Z could be an integer, e.g. Z=16, 32, 64, etc; and/or up to Z1 UL (Z2 DL) HARQ process number can be increased based on sharing from DL (UL) HARQ process. The UE could report the HARQ process which could be shared, e.g. (Z1, Z2) : (8, 0) , (16, 0) , (0, 8) , (0, 16) , (8, 8) , or (16, 16) . For example, Z=32, (Z1, Z2) = (16, 0) , (X, Y) = (16, 16) , that is the total HARQ process number is not changed, X1=0～16, Y1=16～32. up to 16 UL HARQ process can be configured with 16 shared HARQ process, up to 32 DL HARQ process can be configured with 16 shared HARQ process, the total HARQ process number is 32.

In some implementations, the reported/configured (X, Y) could be determined by D/U proportion based on frame structure. For example, when only DL traffic are scheduled, or optionally the frame structure of the cell is configured with a single period with “DDDDD” for consecutive 5 slots, 16 UL HARQ processes are useless, all of the UL HARQ processes can be shared with DL HARQ processes, e.g. Z1=16, Z2=0, X1=0～16, Y1=16～32. In some implementations, when (Z1, Z2) is not reported by a UE, or only (Z1, Z2) = (0, 0) is reported, the dynamic HARQ sharing is not supported.

In some implementations, a total HARQ process number Z may be increased, wherein Z is an integer, e.g. Z=16, 32, 64, etc; and/or up to Z1 UL (Z2 DL) HARQ process number can be increased based on sharing from DL (UL) HARQ process. For example, 32≤Z≤64, (X, Y) : { (16, 16) , (8, 32) , (16, 32) , (32, 8) , (32, 16) } . UE could report the HARQ process which could be shared, e.g. (Z1, Z2) : { (16, 0) , (8, 0) , (0, 8) , (0, 16) , (32, 16) } . As a result, HARQ sharing or HARQ process number increase could be achieved. For example, Z=48, (Z1, Z2) = (16, 0) , (X, Y) = (16, 32) , that is the total HARQ process number is increased, X1=0～16, Y1=32～48. up to 16 UL HARQ process can be configured with 16 shared HARQ process, up to 48 DL HARQ process can be configured with 16 shared HARQ process, the total HARQ process number is 48.

In some implementations, (X1, Y1) is configured for a UE or reported by a UE. In some implementations, (Z1, Z2) is configured for a UE or reported by a UE.

In some implementations, HARQ sharing could be achieved by α*X+β*Y ≤ Z. wherein the scaling factor α, β can be predefined or configured.

In some implementations, (X, Y) , (X1, Y1) , and/or (Z1, Z2) could be UL HARQ process number and DL HARQ process number for one cell, a cell group, a band or a UE; or UL HARQ process numbers for different cells, cell groups or bands, or DL HARQ process numbers for different cells, cell groups or bands.

In some implementations, dynamic HARQ sharing could be achieved by different values of (X, Y) switching. For example, (X, Y) = (16, 16) before dynamic HARQ sharing switch, after switch, (X, Y) = (24, 8) which means 8 DL HARQ process numbers are shared for UL HARQ process.

In some implementations, when dynamic HARQ sharing is applied, the association between DL HARQ process number and UL HARQ process number are predefined or configured. For example, Z=32, (Z1, Z2) = (16, 0) , (X, Y) = (16, 16) , that is the total HARQ process number is not changed, X1=0～16, Y1=16～32. up to 16 UL HARQ process can be configured with 16 shared HARQ process, up to 32 DL HARQ process can be configured with 16 shared HARQ process, the total HARQ process number is 32. In some implementations, the DL HARQ 16 to 31 is corresponded or associated with UL HARQ 0 to 15.

The present disclosure describes methods, apparatus, and computer-readable medium for wireless data service. The present disclosure addressed the issues with HARQ process in a wireless communication system. The methods, devices, and computer-readable medium described in the present disclosure may facilitate the performance of data service, thus improving efficiency and overall performance. The methods, devices, and computer-readable medium described in the present disclosure may improves the overall efficiency of the wireless communication systems.

In some other embodiments, a computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out the above methods. The computer-readable medium may be referred as non-transitory computer-readable media (CRM) that stores data for extended periods such as a flash drive or compact disk (CD) , or for short periods in the presence of power such as a memory device or random access memory (RAM) . In some embodiments, computer-readable instructions may be included in a software, which is embodied in one or more tangible, non-transitory, computer-readable media. Such non-transitory computer-readable media can be media associated with user-accessible mass storage as well as certain short-duration storage that are of non-transitory nature, such as internal mass storage or ROM. The software implementing various embodiments of the present disclosure can be stored in such devices and executed by a processor (or processing circuitry) . A computer-readable medium can include one or more memory devices or chips, according to particular needs. The software can cause the processor (including CPU, GPU, FPGA, and the like) to execute particular processes or particular parts of particular processes described herein, including defining data structures stored in RAM and modifying such data structures according to the processes defined by the software. In various embodiments in the present disclosure, the term “processor” may mean one processor that performs the defined functions, steps, or operations or a plurality of processors that collectively perform defined functions, steps, or operations, such that the execution of the individual defined functions may be divided amongst such plurality of processors.

Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present solution should be or are included in any single implementation thereof. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present solution. Thus, discussions of the features and advantages, and similar language, throughout the specification may, but do not necessarily, refer to the same embodiment.

Furthermore, the described features, advantages and characteristics of the present solution may be combined in any suitable manner in one or more embodiments, for non-limiting examples, a portion from one or more embodiment may be combined with another portion of other embodiments. One of ordinary skill in the relevant art will recognize, in light of the description herein, that the present solution can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the present solution.

Claims

A method for wireless communication, performed by a wireless communication device, comprising:

receiving, by a user equipment (UE) , a first physical download shared channel (PDSCH) in a first cell, and

determining, by the UE, a hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback for the first PDSCH corresponding to a HARQ process, for transmitting on a second cell.
A method for wireless communication, performed by a wireless communication node, comprising:

sending, by a base station, a first physical download shared channel (PDSCH) in a first cell, and

receiving, by the base station, a hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback for the first PDSCH corresponding to a HARQ process, via a second cell.
The method according to any of claims 1 to 2, wherein:

the first cell and the second cell are different cells, the HARQ-ACK feedback is transmitted in the second cell which is a primary cell (PCell) , and the first PDSCH is transmitted in the first cell which is a secondary cell (SCell) ; or

the first cell and the second cell are a same cell.
The method according to any of claims 1 to 3, wherein:

after receiving the first PDSCH corresponding to the HARQ process, the UE receives one or more second PDSCHs corresponding to the same HARQ process before an expected transmission of the HARQ-ACK feedback for the HARQ process.
The method according to claim 4, wherein:

a maximum number of PDSCHs corresponding to the same HARQ process is predefined or configured, wherein the PDSCHs comprises the first PDSCH and the one or more second PDSCHs.
The method according to claim 5, wherein:

the maximum number of PDSCHs corresponding to the same HARQ process is determined to be inversely proportional to the maximum number of HARQ processes.
The method according to claim 4, wherein:

a time duration is added to a PDSCH processing time;

a time interval between consecutive PDSCHs corresponding to the same HARQ process is predefined or configured; or

the UE’s receiving one or more second PDSCHs corresponding to the same HARQ process before the expected transmission of the HARQ-ACK feedback for the HARQ process is enabled or disabled dynamically or semi-statically.
The method according to any of claims 1 to 3, wherein:

the HARQ-ACK feedback is transmitted based on either a single physical uplink control channel (PUCCH) cell group or two PUCCH cell groups.
The method according to claim 8, wherein:

the HARQ-ACK feedback is transmitted based on two PUCCH cell groups, and the HARQ-ACK feedback is reported cross the two PUCCH cell groups.
The method according to claim 9, wherein:

a time duration is added to a PDSCH processing time;

HARQ-ACK codebooks of the two PUCCH cell groups are appended, wherein the HARQ-ACK codebooks have same or different codebook types;

PUCCH resource for transmitting the HARQ-ACK feedback is determined by the PUCCH cell group that is applied; or

a PUCCH cell group or PUCCH resource in which the PUCCH cell group for transmitting the HARQ-ACK feedback is indicated by a downlink control information (DCI) .
The method according to claim 8, wherein:

switching between the single PUCCH cell group and the two PUCCH cell groups is indicated by a DCI or a medium access control (MAC) control element (CE) .
The method according to claim 11, wherein:

all cells in the two PUCCH cell groups are comprised in the single PUCCH cell group; or

the switching between the single PUCCH cell group and the two PUCCH cell groups is performed by enabling or disabling PUCCH SCell or one of the two PUCCH cell groups.
The method according to any of claims 1 to 3, wherein:

a transport block (TB) size of a TB which is carried on the first PDSCH on multiple slots is increased.
The method according to claim 13, wherein:

a total number of resource elements (REs) in the TB is determined by one slot combined with a scaling factor, wherein the scaling factor is equal to or larger than 1; or

a time duration is added to a PDSCH processing time.
The method according to any of claims 1 to 3, wherein:

HARQ process sharing is performed between downlink (DL) HARQ processes and uplink (UL) HARQ processes.
The method according to claim 15, wherein:

a number of the DL HARQ processes increases by sharing from the UL HARQ processes;

a number of the UL HARQ processes increases by sharing from the DL HARQ processes; or

the HARQ process sharing is determined based on a DL and UL proportion within a frame structure.
The method according to any of claims 1 to 3 and 15 to 16, wherein:

a total number of DL HARQ processes and UL HARQ processes is maintained as a predefined number; or

a number of DL HARQ processes and a number of UL HARQ processes is proportional to DL slots and UL slots in a frame structure.
The method according to any of claims 1 to 3 and 15 to 16, wherein:

a total number of DL HARQ processes and UL HARQ processes is maintained dynamically as a predefined number; or

a number of DL HARQ processes and a number of UL HARQ processes is determined according to a first shared HARQ process number and a second shared HARQ process number, wherein the first shared HARQ process number is from the UL processes to the DL processes, and the second shared HARQ process number is from the DL processes to the UL processes.
A wireless communications apparatus comprising at least one processor and a memory, wherein the at least one processor is configured to read code from the memory and implement a method recited in any of claims 1 to 18.
A computer program product comprising a computer-readable program medium code stored thereupon, the computer-readable program medium code, when executed by at least one processor, causing the at least one processor to implement a method recited in any of claims 1 to 18.