Feedback-triggered TX / RX for UE based on multiple ACK / NACK

Abstract

The present disclosure provides systems, devices, apparatuses and methods for ACK / NACK triggered communication with a UE based on multiple ACK / NACK bits in HARQ feedback from the UE, including computer programs encoded on storage media. The UE may receive a configuration for a resource, monitor one or more PDSCH transmissions, and send an uplink transmission including HARQ feedback, the HARQ feedback carrying multiple NACK or ACK bits for one or more PDSCH transmissions. The UE may send or receive communication in a resource based on a trigger in the HARQ feedback for sending or receiving communication in the resource.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit and priority of the following applications: U.S. Provisional Application Serial No. 63 / 075,051, filed on September 4, 2020 and entitled “Feedback Triggered Tx / Rx for a UE based on Multiple ACK / NACK”; and U.S. Patent Application No. 17 / 407,812, filed on August 20, 2021 and entitled “FEEDBACK TRIGGERED TX / RX FOR A UE BASED ON MULTIPLE ACK / NACK”, the entire contents of the above applications are expressly incorporated herein by reference. Technical Field

[0003] Generally, the present disclosure relates to communication systems, and more particularly, the present disclosure relates to wireless communications including feedback triggered reception / transmission (Tx / Rx). Background Art

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcast. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0005] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of the continuous mobile broadband evolution released by the Third Generation Partnership (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., together with the Internet of Things (IoT)) and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communications (URLLC). Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There is a need for further improvement of 5G NR technology. These improvements may also be applicable to other multiple access technologies and telecommunication standards that employ these technologies. Summary of the invention

[0006] A brief summary of one or more aspects is given below to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is neither intended to identify key or important elements of all aspects, nor to delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be presented later.

[0007] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may receive a configuration for a resource; monitor one or more PDSCH transmissions; send an uplink transmission including a hybrid automatic repeat request (HARQ) feedback, the HARQ feedback carrying a plurality of negative acknowledgement (NACK) or acknowledgement (ACK) bits for the one or more PDSCH transmissions; and send or receive the communication in the resource based on a trigger in the HARQ feedback for sending or receiving the communication in the resource.

[0008] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may send a configuration for resources associated with one or more PDSCH transmissions; receive an uplink transmission including HARQ feedback from a UE, the HARQ feedback carrying multiple NACK or ACK bits for the one or more PDSCH transmissions; and send a channel state information-reference signal (CSI-RS) or receive a sounding reference signal (SRS) in the resource based on a trigger in the HARQ feedback for sending the CSI-RS or receiving the SRS in the resource.

[0009] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may receive a configuration of resources associated with one or more PDSCH transmissions from a base station; receive an uplink transmission including HARQ feedback from a second wireless device, the HARQ feedback carrying multiple NACK or ACK bits for the one or more PDSCH transmissions; and send a sidelink retransmission of at least one of the one or more PDSCH transmissions in the resource based on a trigger in the HARQ feedback for sending the sidelink retransmission in the resource.

[0010] To achieve the aforementioned and related purposes, one or more aspects include features fully described below and particularly pointed out in the claims. The following description and drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of only some of the various ways in which the principles of the various aspects can be employed, and this specification is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a diagram illustrating an example of a wireless communication system and an access network.

[0012] Figure 2A is a diagram illustrating an example of a first frame according to various aspects of the present disclosure.

[0013] Figure 2B is a diagram illustrating an example of DL channels within a subframe according to various aspects of the present disclosure.

[0014] Figure 2C is a diagram illustrating an example of a second frame according to various aspects of the present disclosure.

[0015] Figure 2D is a diagram illustrating an example of UL channels within a subframe according to various aspects of the present disclosure.

[0016] Figure 3 is a diagram showing an example of a base station and a user equipment (UE) in an access network.

[0017] Figure 4 is a call flow diagram illustrating communications between a base station, a UE, and a relay UE.

[0018] Figure 5 is a diagram illustrating a sounding reference signal (SRS) transmission triggered by a negative acknowledgement (NACK) from a UE.

[0019] Figure 6 is a diagram illustrating NACK-triggered channel state information reference signal (CSI-RS) transmission from a base station.

[0020] Figure 7 is a diagram illustrating NACK-triggered retransmission from a relay UE.

[0021] Figure 8 is a flow chart of a method of wireless communication at a UE.

[0022] Fig. 9 is a flow chart of a method of wireless communication at a UE.

[0023] Fig.10 is a flow chart of a wireless communication method at a base station.

[0024] Fig.11 is a flow chart of a method of wireless communication at a base station.

[0025] Fig.12 is a flow chart of a method of wireless communication at a wireless device.

[0026] Fig.13is a flow chart of a method of wireless communication at a wireless device.

[0027] Fig.14 is a diagram illustrating an example of a hardware implementation for an example apparatus.

[0028] Fig.15 is a diagram illustrating an example of a hardware implementation for an example apparatus.

[0029] Fig.16 is a diagram illustrating an example of a hardware implementation for an example apparatus. DETAILED DESCRIPTION

[0030] The specific embodiments described below in conjunction with the accompanying drawings are intended to be descriptions of various configurations and are not intended to represent the only configurations with which the concepts described herein can be practiced. For the purpose of providing a comprehensive understanding of each concept, the specific embodiments include specific details. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, well-known structures and components are shown in the form of block diagrams to avoid obscuring such concepts.

[0031] Several aspects of telecommunication systems will now be presented with reference to various devices and methods. These devices and methods will be described in the following detailed description by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements") and illustrated in the accompanying drawings. These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0032] For example, an element, or any part of an element, or any combination of elements, may be implemented as a "processing system" including one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on chip (SoCs), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gating logic, discrete hardware circuits, and other suitable hardware configured to perform various functions described throughout the present disclosure. One or more processors in a processing system may execute software. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other names, software should be broadly interpreted as meaning instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, processes, functions, etc.

[0033] Accordingly, in one or more examples, the described functions can be implemented in hardware, software, or any combination thereof. If implemented in software, the functions can be stored or encoded as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media. Storage media can be any available media that can be accessed by a computer. By way of example and not limitation, such computer-readable media may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, a combination of computer-readable media of the above types, or any other medium that can be used to store computer executable code that can be accessed by a computer in the form of instructions or data structures.

[0034] Although various aspects and implementations are described in this application by the description of some examples, it will be understood by those skilled in the art that additional implementations and use cases may be generated in many different arrangements and scenarios. The innovation described herein can be implemented across many different platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, implementations and / or use can be generated via integrated chip implementations and other devices based on non-module components (e.g., end-user devices, vehicles, communication equipment, computing equipment, industrial equipment, retail / purchase equipment, medical equipment, equipment enabling artificial intelligence (AI), etc.). Although some examples may or may not be specifically for use cases or applications, there may be a variety of applicable scopes for the described innovations. Implementations can vary from chip-level or modular components to non-modular, non-chip-level implementations, and further to the range of aggregated, distributed, or original equipment manufacturer (OEM) equipment or systems incorporating one or more aspects of the described innovations. In some actual settings, the equipment incorporating the described aspects and features may also include additional components and features for implementing and implementing the claimed and described aspects. For example, the transmission and reception of wireless signals necessarily include multiple components for analog and digital purposes (e.g., hardware components including antennas, radio frequency (RF) chains, power amplifiers, modulators, buffers, processors, interleavers, adders / summers, etc.). The innovations described herein are intended to be implemented in a variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc., having different sizes, shapes, and configurations.

[0035] In ultra-reliable low-latency communications (URLLC) and industrial Internet of Things (IIoT), a shortened time period for retransmission and / or channel sounding can be used to reduce the latency after a failed physical downlink shared channel (PDSCH) transmission from a base station to a user equipment (UE). In an example, downlink control information (DCI) scheduling overhead and latency can be reduced based on retransmission and / or channel sounding directly triggered by a negative acknowledgement (NACK) from the UE. Since a NACK can indicate a failed PDSCH transmission, the NACK can be used as a triggering mechanism for triggering communication between the UE and the base station with reduced latency.

[0036] In some configurations, NACK can be used to trigger a sounding reference signal (SRS) transmission from a UE, a channel state information-reference signal (CSI-RS) transmission from a base station, or a sidelink retransmission from a relay UE. Although the trigger mechanism can be based on the transmission of a NACK from a UE (or, in some configurations, the transmission of an acknowledgement (ACK) from a UE), an uplink (UL) transmission can include multiple ACK / NACK bits corresponding to multiple PDSCH transmissions. Therefore, activation of the trigger mechanism can apply to a subset of ACK / NACK bits in the multiple ACK / NACK bits (e.g., corresponding to NACK), but not to the remaining portion of the ACK / NACK bits (e.g., corresponding to ACK).

[0037] Assuming that a single UL transmission may include multiple ACK / NACK bits corresponding to multiple PDSCH transmissions, some bits in the UL transmission may correspond to ACK, and other bits in the UL transmission may correspond to NACK. That is, a single UL transmission (which may include one bit for each of the multiple PDSCH transmissions) may have one or more ACK bits and / or one or more NACK bits. Therefore, the trigger mechanism for SRS transmissions from the UE, CSI-RS transmissions from the base station, and sidelink retransmissions from the relay UE may be based on the ACK / NACK of a single UL transmission. The base station or UE may have to determine combined feedback (e.g., multi-bit HARQ feedback) to initiate the trigger mechanism. The various aspects given herein enable the base station and the UE to determine how to apply the trigger protocol to combined feedback for multiple PDSCH transmissions.

[0038] In the first aspect, if at least one NACK bit is included in a plurality of ACK / NACK bits associated with a UL transmission, transmission / reception may be triggered. In the second aspect, if all ACK / NACK bits in a plurality of ACK / NACK bits associated with a UL transmission correspond to NACK, transmission / reception may be triggered. In the third aspect, if the percentage of NACK bits in a plurality of ACK / NACK bits exceeds a threshold percentage, transmission / reception may be triggered. The threshold percentage may be a fixed threshold (e.g., based on a defined protocol) or a threshold dynamically signaled (e.g., via DCI, medium access control-control element (MAC-CE), radio resource control (RRC), etc.). In another configuration, each of the three aspects may be implemented by triggering transmission / reception based on an ACK bit (rather than a NACK bit).

[0039] Figure 1 1 is a diagram showing an example of a wireless communication system and access network 100. The wireless communication system (also referred to as a wireless wide area network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). The base station 102 may include a macro cell (a high-power cellular base station) and / or a small cell (a low-power cellular base station). A macro cell includes a base station. A small cell includes a femto cell, a pico cell, and a micro cell.

[0040] The base station 102 configured for 4G LTE (collectively referred to as the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with the EPC 160 via a first backhaul link 132 (e.g., an S1 interface). The base station 102 configured for 5G NR (collectively referred to as the Next Generation RAN (NG-RAN)) can interface with the core network 190 via a second backhaul link 184. Among other functions, the base station 102 can also perform one or more of the following functions: transmission of user data, wireless channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), user and device tracking, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 may communicate with each other directly or indirectly (eg, via the EPC 160 or the core network 190) via a third backhaul link 134 (eg, an X2 interface). The first backhaul link 132, the second backhaul link 184, and the third backhaul link 134 may be wired or wireless.

[0041] Base station 102 can communicate wirelessly with UE 104. Each base station 102 in base station 102 can provide communication coverage for a corresponding geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, a small cell 102' may have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network including both small cells and macro cells may be referred to as a heterogeneous network. A heterogeneous network may also include a home evolved Node B (eNB) (HeNB), which may provide services to a restricted group referred to as a closed subscriber group (CSG). A communication link 120 between base station 102 and UE 104 may include UL (also referred to as a reverse link) transmission from UE 104 to base station 102 and / or downlink (DL) (also referred to as a forward link) transmission from base station 102 to UE 104. The communication link 120 may use multiple input multiple output (MIMO) antenna technology, including spatial multiplexing, beamforming and / or transmit diversity. The communication link may be through one or more carriers. Base station 102 / UE 104 may use spectrum of up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in carrier aggregation for a total of up to Yx MHz (x component carriers) for transmission in each direction. The carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​compared to UL). The component carrier may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell), and the secondary component carrier may be referred to as a secondary cell (SCell).

[0042] Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use DL / UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). The D2D communication may be through a variety of wireless D2D communication systems, such as, for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

[0043] The wireless communication system may also include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154 in, for example, a 5 GHz unlicensed spectrum. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) prior to communication to determine whether the channel is available.

[0044] The small cell 102' may operate in a licensed and / or unlicensed spectrum. When operating in an unlicensed spectrum, the small cell 102' may employ NR and use the same unlicensed spectrum (e.g., 5 GHz, etc.) as used by the Wi-Fi AP 150. The small cell 102' employing NR in the unlicensed spectrum may improve coverage of the access network and / or increase capacity of the access network.

[0045] The electromagnetic spectrum is typically subdivided into various categories, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating bands have been identified with the frequency range names FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz. Frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often (interchangeably) referred to as the "sub-6 GHz" band in various documents and articles. Similar naming issues sometimes arise regarding FR2, although unlike the extremely high frequency (EHF) band (30 GHz-300 GHz) which is identified as the "millimeter wave" band by the International Telecommunication Union (ITU), FR2 is often (interchangeably) referred to as the "millimeter wave" band in documents and articles.

[0046] Frequencies between FR1 and FR2 are generally referred to as mid-band frequencies. Recent 5G NR research has identified the operating bands of these mid-band frequencies as the frequency range name FR3 (7.125GHz–24.25GHz). The frequency bands falling within FR3 can inherit FR1 characteristics and / or FR2 characteristics, and can therefore effectively extend the characteristics of FR1 and / or FR2 to mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operations above 52.6GHz. For example, three higher operating bands have been identified as the frequency range names FR4a or FR4-1 (52.6GHz–71GHz), FR4 (52.6GHz–114.25GHz), and FR5 (114.25GHz–300GHz). Each of these higher frequency bands falls within the EHF band.

[0047] In view of the above, unless otherwise specifically stated, it should be understood that the term "sub-6 GHz" and the like (if used herein) can broadly refer to frequencies that can be less than 6 GHz, frequencies that can be within FR1, or frequencies that can include mid-band frequencies. In addition, unless otherwise specifically stated, it should be understood that the term "millimeter wave" and the like (if used herein) can broadly refer to frequencies that can include mid-band frequencies, frequencies that can be within FR2, FR4, FR4-a or FR4-1 and / or FR5, or frequencies that can be within the EHF band.

[0048] The base station 102, whether a small cell 102' or a large cell (e.g., a macro base station), may include and / or be referred to as an eNB, a gNodeB (gNB), or another type of base station. Some base stations, such as gNB 180, may operate in traditional sub-6 GHz spectrum, in millimeter wave frequencies, and / or near millimeter wave frequencies to communicate with UE 104. When the gNB 180 operates in millimeter wave or near millimeter wave frequencies, the gNB 180 may be referred to as a millimeter wave base station. The millimeter wave base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short distance. The base station 180 and the UE 104 may each include multiple antennas, such as antenna elements, antenna panels, and / or antenna arrays, to facilitate beamforming.

[0049] Base station 180 may transmit beamformed signals in one or more transmit directions 182' to UE 104. UE 104 may receive beamformed signals from base station 180 in one or more receive directions 182". UE 104 may also transmit beamformed signals to base station 180 in one or more transmit directions. Base station 180 may receive beamformed signals from UE 104 in one or more receive directions. Base station 180 / UE 104 may perform beam training to determine the best receive and transmit directions for each of base station 180 / UE 104. The transmit direction and receive direction for base station 180 may or may not be the same. The transmit direction and receive direction for UE 104 may or may not be the same.

[0050] The EPC 160 may include a mobility management entity (MME) 162, other MMEs 164, a serving gateway 166, a multimedia broadcast multicast service (MBMS) gateway 168, a broadcast multicast service center (BM-SC) 170, and a packet data network (PDN) gateway 172. The MME 162 may communicate with a home subscriber server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. Typically, the MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through the serving gateway 166, which itself is connected to the PDN gateway 172. The PDN gateway 172 provides IP address allocation to the UE as well as other functions. The PDN gateway 172 and the BM-SC 170 are connected to IP services 176. The IP services 176 may include the Internet, an intranet, an IP multimedia subsystem (IMS), PS streaming services, and / or other IP services. The BM-SC 170 may provide functionality for MBMS user service provision and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS gateway 168 may be used to distribute MBMS services to base stations 102 belonging to a multicast broadcast single frequency network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start / stop) and for collecting eMBMS-related charging information.

[0051] The core network 190 may include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. The AMF 192 may communicate with a unified data management unit (UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. Typically, the AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are transmitted through the UPF 195. The UPF 195 provides UE IP address allocation and other functions. The UPF 195 is connected to an IP service 197. The IP service 197 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a packet switching (PS) stream service, and / or other IP services.

[0052] A base station may include and / or be referred to as a gNB, a Node B, an eNB, an access point, a base transceiver, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit receive point (TRP), or some other appropriate term. The base station 102 provides an access point to the EPC 160 or the core network 190 for the UE 104. Examples of UE 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio unit, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., an MP3 player), a camera, a game console, a tablet computer, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, or any other similarly functional device. Some of the UEs 104 may be referred to as IoT devices (e.g., a parking meter, a gas pump, an oven, a vehicle, a heart monitor, etc.). UE 104 may also be referred to as a station, a mobile station, a user station, a mobile unit, a user unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile user station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handheld device, a user agent, a mobile client, a client, or some other suitable terminology.

[0053] Refer again Figure 1 In some aspects, the UE 104 may include a communication trigger component 198, which is configured to: receive a configuration for resources; monitor one or more PDSCH transmissions; send an uplink transmission including HARQ feedback, the HARQ feedback carrying multiple NACK or ACK bits for one or more PDSCH transmissions; and send or receive communications in the configured resources based on a trigger in the HARQ feedback for sending or receiving communications in the configured resources. In some examples, the trigger may be at least one NACK bit. In some examples, the trigger may be that the percentage of NACK bits meets a threshold. In some examples, the trigger may be that each ACK / NACK bit in the ACK / NACK bits is NACK. In some examples, the trigger may be at least one ACK bit. In some examples, the trigger may be that the percentage of ACK bits meets a threshold. In some examples, the trigger may be that each ACK / NACK bit in the ACK / NACK bits is ACK.

[0054] In certain aspects, the base station 102 or 180 may include a triggered communication component 199, which is configured to: send a configuration for resources associated with one or more PDSCH transmissions; receive an uplink transmission from a UE including HARQ feedback, the HARQ feedback carrying multiple NACK or ACK bits for one or more PDSCH transmissions; and send CSI-RS or receive SRS in the configured resources based on a trigger in the HARQ feedback for sending CSI-RS or receiving SRS in the configured resources.

[0055] In certain aspects, a wireless device (e.g., a relay UE) may include a communication relay component 107, which is configured to: receive a configuration of resources associated with one or more PDSCH transmissions from a base station; receive an uplink transmission including HARQ feedback from a second wireless device, the HARQ feedback carrying multiple NACK or ACK bits for the one or more PDSCH transmissions; and send a sidelink retransmission in the configured resources based on a trigger in the HARQ feedback for sending a sidelink retransmission of at least one of the one or more PDSCH transmissions in the configured resources.

[0056] Although the following description may focus on 5G NR, the concepts described herein may be applicable to other similar areas such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

[0057] Figure 2A is a diagram 200 showing an example of a first subframe within a 5G NR frame structure. Figure 2B is a schematic diagram 230 showing an example of DL channels within a 5G NR subframe. Figure 2C is a diagram 250 showing an example of a second subframe within a 5G NR frame structure. Figure 2D 280 is a diagram showing an example of UL channels within a 5G NR subframe. The 5G NR frame structure can be frequency division duplex (FDD) (wherein, for a particular set of subcarriers (carrier system bandwidth), a subframe within a subcarrier set is dedicated to either DL or UL), or can be time division duplex (TDD) (wherein, for a particular set of subcarriers (carrier system bandwidth), a subframe within a subcarrier set is dedicated to both DL and UL). Figure 2A , 2CIn the example provided, the 5G NR frame structure is assumed to be TDD, where subframe 4 is configured with slot format 28 (most of which are DL), where D is DL, U is UL, and F is flexible between DL / UL, and subframe 3 is configured with slot format 1 (all of which are UL). Although subframes 3 and 4 are shown as having slot formats 1 and 28, respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are full DL and full UL, respectively. Other slot formats 2-61 include a mix of DL, UL and flexible symbols. The UE is configured with a slot format (dynamically configured by DCI, or semi-statically / statically configured by RRC signaling) through the received slot format indicator (SFI). Note that the following description also applies to the 5GNR frame structure of TDD.

[0058] Figures 2A-2D The frame structure is shown, and various aspects of the present disclosure may be applicable to other wireless communication technologies, which may have different frame structures and / or different channels. A frame (10ms) may be divided into 10 subframes (1ms) of equal size. Each subframe may include one or more time slots. A subframe may also include a microslot, which may include 7, 4 or 2 symbols. Each time slot may include 14 or 12 symbols, depending on whether the cyclic prefix (CP) is normal or extended. For a normal CP, each time slot may include 14 symbols, and for an extended CP, each time slot may include 12 symbols. The symbol on the DL may be a CP orthogonal frequency division multiplexing (OFDM) (CP-OFDM) symbol. The symbol on the UL may be a CP-OFDM symbol (for high throughput scenarios) or a discrete Fourier transform (DFT) extended OFDM (DFT-s-OFDM) symbol (also referred to as a single carrier frequency division multiple access (SC-FDMA) symbol) (for power-limited scenarios; limited to single stream transmission). The number of time slots within a subframe may be based on CP and numerology. The digital scheme defines the subcarrier spacing (SCS) and, in effect, the symbol length / duration (which may be equal to 1 / SCS).

[0059] μ <![CDATA[SCSΔf=2 μ ·15[kHz]]]> Cyclic prefix 0 15 ordinary 1 30 ordinary 2 60 Normal, Extended 3 120 ordinary 4 240 ordinary

[0060] For normal CP (14 symbols / slot), different digital schemes μ0 to 4 allow 1, 2, 4, 8, and 16 slots per subframe, respectively. For extended CP, digital scheme 2 allows 4 slots per subframe. Accordingly, for normal CP and digital scheme μ, there are 14 symbols / slot and 2 μ timeslots / subframe. The subcarrier spacing can be equal to 2 μ*15kHz, where μ is digital scheme 0 to 4. Thus, digital scheme μ=0 has a subcarrier spacing of 15kHz, and digital scheme μ=4 has a subcarrier spacing of 240kHz. The symbol length / duration is inversely related to the subcarrier spacing. Figures 2A-2D An example is provided for a normal CP with 14 symbols per slot and a digital scheme μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a frame set, there may be one or more different bandwidth parts (BWPs) that are frequency-division multiplexed (see Figure 2B ). Each BWP can have a specific number scheme and CP (normal or extended).

[0061] The resource grid can be used to represent the frame structure. Each time slot includes a resource block (RB) (also called a physical RB (PRB)), which includes 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0062] As in Figure 2A As shown in , some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) for channel estimation at the UE (indicated as R for a specific configuration, but other DM-RS configurations are possible) and a CSI-RS. The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and a phase tracking RS (PT-RS).

[0063] Figure 2BExamples of various DL channels within a subframe of a frame are shown. A physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), each CCE including six RE groups (REGs), each REG including 12 consecutive REs in an OFDM symbol of an RB. A PDCCH within a BWP may be referred to as a control resource set (CORESET). The UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., a common search space, a UE-specific search space) during a PDCCH monitoring opportunity on a CORESET, wherein the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at larger and / or lower frequencies across the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of a particular subframe of a frame. The PSS is used by UE 104 to determine subframe / symbol timing and physical layer identification. A secondary synchronization signal (SSS) may be within symbol 4 of a particular subframe of a frame. The SSS is used by the UE to determine the physical layer cell identity group number and the radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine the physical cell identifier (PCI). Based on the PCI, the UE can determine the position of the above-mentioned DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block (also referred to as an SS block (SSB)). The MIB provides the number of RBs in the system bandwidth and the system frame number (SFN). The PDSCH carries user data, broadcast system information not sent via the PBCH (such as a system information block (SIB)), and paging messages.

[0064] As in Figure 2C As shown in , some of the REs carry DM-RS for channel estimation at the base station (indicated as R for a specific configuration, but other DM-RS configurations are possible). The UE can send DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS can be sent in the first one or two symbols of the PUSCH. The PUCCH DM-RS can be sent in different configurations depending on whether a short PUCCH or a long PUCCH is sent and depending on the specific PUCCH format used. The UE can send an SRS. The SRS can be sent in the last symbol of the subframe. The SRS can have a comb structure, and the UE can send the SRS on one of the comb structures. The SRS can be used by the base station for channel quality estimation to achieve frequency-dependent scheduling on the UL.

[0065] Figure 2DExamples of various UL channels within a subframe of a frame are shown. The PUCCH may be positioned as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and hybrid automatic repeat request (HARQ) ACK / NACK bits. The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0066] Figure 3 3 is a block diagram of a base station 310 communicating with a UE 350 in an access network. In the DL, IP packets from the EPC 160 may be provided to the controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functions. Layer 3 includes the RRC layer, and layer 2 includes the service data adaptation protocol (SDAP) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, and the medium access control (MAC) layer. The controller / processor 375 provides: RRC layer functions associated with: broadcasting of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functions associated with: header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and switching support functions; RLC layer functions associated with: transmission of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with: mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0067] The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functions associated with various signal processing functions. Layer 1 including the physical (PHY) layer may include error detection of the transmission channel, forward error correction (FEC) encoding / decoding of the transmission channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 processes the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-order quadrature amplitude modulation (M-QAM)). The coded and modulated symbols can then be divided into parallel streams. Each stream can then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time domain and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to generate multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine coding and modulation schemes and for spatial processing. Channel estimates may be derived based on reference signals and / or channel condition feedback sent by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0068] At the UE 350, each receiver 354RX receives a signal through its corresponding antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to a receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functions associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial stream destined for the UE 350. If multiple spatial streams are destined for the UE 350, they can be combined into a single OFDM symbol stream by the RX processor 356. The RX processor 356 then uses a fast Fourier transform (FFT) to convert the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier and the reference signal are recovered and demodulated by determining the most likely signal constellation point sent by the base station 310. These soft decisions can be based on the channel estimate calculated by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by the base station 310. The data and control signals are then provided to the controller / processor 359 which implements layer 3 and layer 2 functions.

[0069] The controller / processor 359 may be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer readable medium. In the UL, the controller / processor 359 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between transport channels and logical channels to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using an ACK and / or NACK protocol to support HARQ operations.

[0070] Similar to the functions described in conjunction with DL transmissions performed by the base station 310, the controller / processor 359 provides: RRC layer functions associated with: system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with: header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with: transmission of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with: mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0071] Channel estimates derived by the channel estimator 358 based on a reference signal or feedback sent by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0072] UL transmissions are processed at the base station 310 in a manner similar to that described in conjunction with the receiver functionality at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

[0073] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover IP packets from the UE 350. The IP packets from the controller / processor 375 may be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0074] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to perform operations related to Figure 1 Various aspects related to the communication relay component 107.

[0075] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to perform operations related to Figure 1 Various aspects related to the communication trigger component 198.

[0076] At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 may be configured to perform operations related to Figure 1 Various aspects related to the triggered communication component 199.

[0077] Wireless communication systems can be configured to share available system resources and provide various telecommunication services (e.g., telephone, video, data, messaging, broadcast, etc.) based on multiple access technologies that support communication with multiple users (such as CDMA systems, TDMA systems, FDMA systems, OFDMA systems, SC-FDMA systems, and TD-SCDMA systems, etc.). In many cases, common protocols that facilitate communication with wireless devices are adopted in various telecommunication standards. For example, communication methods associated with eMBB, mMTC, and URLLC may be incorporated into the 5G NR telecommunication standard, while other aspects may be incorporated into the 4G LTE standard. Since mobile broadband technology is part of the ongoing evolution, further improvements to mobile broadband remain useful for continuing the development of such technology.

[0078] Figure 44 is a call flow diagram 400 illustrating communication between a base station 404, a UE 402, and a relay UE 403. The term "relay UE" is used to identify a UE 403. The relay UE 403 may be any type of UE. At 406a, the base station 404 may send a configuration for resources to the UE 402. Resources may be referred to as configured resources in this document. At 406b, the configuration sent for the UE 402 may also be received by the relay UE 403. At 408, both the UE 402 and the relay UE 403 may monitor multiple PDSCH transmissions 407 from the base station 404. In some examples, the PDSCH transmission may be an SPS transmission. At 410, the UE 402 may determine a priority for an UL transmission including HARQ feedback associated with multiple ACK / NACKs. The priority may be a fixed priority determined by the UE 402 or a dynamically signaled priority indicated by the base station 404.

[0079] At 416, UE 402 may determine a trigger for communication between UE 402 and base station 404. In some examples, the trigger may be at least one NACK bit. In some examples, the trigger may be that a percentage of NACK bits meets a threshold. In some examples, the trigger may be that each ACK / NACK bit of the ACK / NACK bits is a NACK. In some examples, the trigger may be at least one ACK bit. In some examples, the trigger may be that a percentage of ACK bits meets a threshold. In some examples, the trigger may be that each ACK / NACK bit of the ACK / NACK bits is an ACK.

[0080] In some examples, the UE may determine the trigger to be applied based on the HARQ-ACK codebook type. For example, the HARQ type 1 codebook may correspond to a trigger for a first communication technology, and the HARQ category 2 codebook may correspond to a trigger for a second communication technology. As an example, the first communication technology may include a sidelink retransmission that is triggered based on: a first metric corresponding to at least one NACK being included in a plurality of ACK / NACK bits of the HARQ feedback 414a, a second metric corresponding to all ACK / NACK bits in the plurality of ACK / NACK bits indicating NACK, and a third metric corresponding to a threshold percentage of ACK / NACK bits indicating NACK. The second communication technology may include a sidelink retransmission that is triggered based on a different metric in the first metric, the second metric, or the third metric.

[0081] In some examples, UE 402 may receive the retransmission directly from base station 404. In other examples, UE 402 may receive the retransmission from a sidelink device such as relay UE 403.

[0082] For example, at 412a, UE 402 may send HARQ feedback to base station 404, the HARQ feedback including multiple ACK / NACKs for multiple PDSCH transmissions monitored at 407. At 412b, the sent HARQ feedback may also be received by relay UE 403. If the HARQ feedback triggers relay UE 403 to retransmit one or more PDSCHs, then at 413, relay UE 403 may retransmit the one or more PDSCHs to UE 402, for example, using the resources configured at 406b. At 414a, UE 402 may send additional HARQ feedback to base station 404 based on the retransmission received at 413. Additional HARQ feedback may also be received by relay UE 403, such that relay UE 403 may relay additional HARQ feedback to base station 404 based on the retransmission at 413 at 414b.

[0083] In other examples, the UE 402 may send SRS communications to the base station 404, such as at 418, based on a NACK trigger in the transmitted HARQ feedback, rather than monitoring sidelink retransmissions. Figure 5 An example is shown in which UE 402 sends SRS based on the NACK bit in the sent HARQ feedback. Figure 5 Described in more detail, the base station 404 may use the SRS to perform fast component carrier (CC) reselection for retransmissions 420 to the UE 402 .

[0084] In some examples, at 418, base station 404 may send a CSI-RS to UE 402 based on a NACK bit in the received HARQ feedback (eg, based on a trigger in a NACK bit of the HARQ feedback). Figure 6 4 shows an example where the base station sends CSI-RS based on the NACK bit in the sent HARQ feedback. UE 402 can provide a CSI report to base station 404 based on the CSI-RS. Figure 6 Described in more detail, the base station 404 may use the CSI-RS to perform fast CC reselection and report to the base station 404 for retransmission 420 to the UE 402 .

[0085] Figure 5-7Figures 500-700 for NACK triggered communications are shown. In URLLC and IIoT, a shortened time period for retransmission and / or channel sounding may be used to reduce latency after a failed PDSCH transmission from a base station. For example, DCI scheduling overhead and latency may be reduced based on retransmission and / or channel sounding triggered based on a NACK from a UE. Since a NACK may indicate a failed PDSCH transmission and a reduction in subsequent DCI scheduling processes, the transmission of a NACK from a UE may be used as a triggering mechanism to provide reduced latency via triggered communications. For example, a NACK may be used to trigger an SRS transmission from a UE (e.g., Figure 5 ), CSI-RS transmission from the base station (such as Figure 6 ), sidelink retransmissions from relay UEs (e.g. Figure 7 In some cases, such as combining Figure 6 As described, the UE may send, for example, a NACK-triggered aperiodic CSI (A-CSI) report for a URLLC process. Although the trigger mechanism may be based on the transmission of a NACK from the UE (or, in some configurations, the transmission of an ACK from the UE), some UL transmissions may include multiple ACK / NACK bits corresponding to multiple PDSCH transmissions. Thus, activation of the trigger mechanism may apply to a subset of the ACK / NACK bits in the multiple ACK / NACK bits, but not to the remainder of the ACK / NACK bits in the multiple ACK / NACK bits.

[0086] In the first aspect, if at least one NACK bit is included in a plurality of ACK / NACK bits associated with a UL transmission of HARQ feedback, transmission / reception may be triggered. For example, if the HARQ feedback includes five ACK / NACK bits, four of which correspond to ACK and one corresponds to NACK, the trigger mechanism may be activated based on one NACK bit included in the UL transmission. If the HARQ feedback includes only ACK feedback, the UE and the base station may avoid performing transmission / reception. Transmission / reception may include any of the following: including in combination with Figure 5 The various aspects of SRS transmission described herein include combining Figure 6 CSI-RS reception and CSI reporting of various aspects described, or including in combination Figure 7 Sidelink retransmissions of various aspects are described.

[0087] In a second aspect, if all ACK / NACK bits of a plurality of ACK / NACK bits associated with a UL transmission of the HARQ feedback correspond to NACK, then the transmission / reception may be triggered. For example, if the HARQ feedback includes five ACK / NACK bits and all five bits correspond to NACK, then the trigger mechanism may be activated. However, even if one ACK / NACK bit of the five ACK / NACK bits corresponds to ACK, based on the foregoing aspects, the trigger mechanism may not be activated. The transmission / reception may include any of the following: including in combination with Figure 5 The various aspects of SRS transmission described herein include combining Figure 6 CSI-RS reception and CSI reporting of various aspects described, or including in combination Figure 7 Sidelink retransmissions of various aspects are described.

[0088] In a third aspect, transmission / reception may be triggered if the percentage of NACK bits among multiple ACK / NACK bits exceeds a threshold percentage. For example, if the UL transmission of the HARQ feedback includes five ACK / NACK bits and the threshold percentage is set to 59%, the trigger mechanism may be activated if three or more of the five ACK / NACK bits correspond to NACK (e.g., 60% or more). If less than 59% of the HARQ feedback indicates NACK (e.g., 2 bits or less), the UE and / or base station may avoid performing transmission / reception. The threshold percentage may be a fixed threshold (e.g., based on a defined protocol) or a threshold that is dynamically signaled (e.g., from a transmitter to a receiver via DCI, MAC-CE, RRC, etc.). In some cases, the base station may be a transmitter that indicates the threshold to a receiver / UE. In other cases, the UE may be a transmitter that indicates the threshold to a receiver / base station. Transmission / reception may include any of the following: including in combination with Figure 5 The various aspects of SRS transmission described herein include combining Figure 6 CSI-RS reception and CSI reporting of various aspects described, or including in combination Figure 7 Sidelink retransmissions of various aspects are described.

[0089] In some examples, selecting / performing a process based on multiple bits of ACK / NACK feedback may be based on a HARQ-ACK codebook type. For example, in a non-limiting example, the UE and / or base station may perform transmission / reception based on at least one NACK being implemented for a HARQ type 2 codebook. The UE and / or base station may also perform transmission / reception based on all ACK / NACK bits corresponding to the NACK being implemented for a HARQ type 1 codebook, and so on.

[0090] In another configuration, each technique may be implemented based on triggering transmission / reception based on ACK bits instead of NACK bits. That is, if at least one ACK bit is included in a plurality of ACK / NACK bits associated with a UL transmission, transmission / reception may be triggered based on a first aspect; if all ACK / NACK bits in a plurality of ACK / NACK bits associated with a UL transmission correspond to ACK, transmission / reception may be triggered based on a second aspect; and / or if a percentage of ACK bits in a plurality of ACK / NACK bits exceeds a threshold percentage, transmission / reception may be triggered based on a third aspect. In addition, Figures 500-700 may be reconfigured based on ACK-triggered communication instead of NACK-triggered communication.

[0091] UL feedback including multiple ACK / NACK bits may have a high PHY priority or a low PHY priority, which may be configured for UL resources or dynamically indicated in DCI scheduling / activation of PDSCH transmission. The priority of UL feedback including multiple ACK / NACK bits may be a fixed priority (e.g., based on a defined protocol for UL feedback) or a priority dynamically signaled (e.g., from a transmitter to a receiver via DCI, MAC-CE, RRC, etc.). In some cases, the base station may be a transmitter that indicates the priority to the receiver / UE. In other cases, the UE may be a transmitter that indicates the priority to the receiver / base station.

[0092] Diagram 500 shows a first example of NACK-triggered communication, where the transmission of SRS 502 associated with reserved resources 504a can be triggered by the ACK / NACK bit of HARQ feedback 506a. According to certain aspects of the present disclosure, Figure 5 The aspects shown in can provide dynamically activated resources for channel measurement. As shown, decoding of data transmission (e.g., PDSCH 508) may have failed on CC1 (e.g., serving CC). A control message (e.g., PUCCH) may be sent by the UE. In some cases, the control message may indicate a NACK, indicating to the UE that decoding of the data transmission has failed. In other cases, the UE may not indicate an ACK or NACK corresponding to the data transmission, which may be referred to as discontinuous transmission (DTX). For example, the UE may not have received control signaling for scheduling of PDSCH 508, and therefore may not send an ACK or NACK for the data transmission.

[0093] As shown, in response to the failure of decoding of PDSCH 508, pre-scheduled resources on a candidate CC (e.g., CC3 or CC4) for transmission of SRS 502 (or reception of CSI-RS) may be activated. The UE may use the pre-scheduled resources to transmit SRS 502, which may be used by the base station to perform channel measurements and select the best candidate CC for downlink data transmission. For example, the base station may send a control message 512 (e.g., PDCCH) to schedule a downlink data transmission 514 (e.g., PDSCH) on CC3. In certain aspects, the UE may send an uplink control message 520 (e.g., PUCCH) indicating an ACK or NACK based on whether decoding of the data transmission 514 is successful.

[0094] As shown, during the second period, the data transmission 518 may be successfully decoded. Accordingly, the UE may send an uplink control message 506b (e.g., PUCCH) acknowledging the data transmission 518. Accordingly, the pre-scheduled resources for SRS may be deactivated (e.g., cancelled or reassigned to other UEs).

[0095] To reduce overhead, channel measurement resources may be pre-configured on candidate CCs, but activated when certain conditions apply. Channel measurement resources may include SRS, CSI-RS, and corresponding UL reporting resources in the case of CSI-RS. Resources may be implicitly activated when NACK / DTX is sent / received for a previously failed transmission. In certain aspects, when the current CC quality (e.g., signal to noise and interference ratio (SINR) or reference signal received power (RSRP)) is below a threshold, the pre-scheduled resources may be explicitly activated by an indicator from the UE to the base station, and the threshold may be configured by the base station. As described herein, if a resource is not activated, the corresponding time / frequency resource may be canceled or reassigned to other UEs.

[0096] In certain aspects, the reference signal may be configured with a beam scanning pattern on a candidate CC, where the SRS / CSI-RS is transmitted / received via different beam pair links. For example, each SRS 502 may be transmitted via a different beam, which may allow signaling quality measurements to be performed for different beams to determine the beam to be used for downlink data transmission. In certain aspects, to further reduce overhead, multiple UEs may share an SRS resource pool and indicate the selected SRS resources (e.g., control message) in a NACK. For example, the resources may be part of a shared (e.g., common) resource pool for multiple UEs. Thus, during different periods, different UEs may use resources (e.g., for receiving CSI-RS) based on the UE performing channel measurements due to reduced signal quality of the UE's current CC.

[0097] The UE may send an SRS 502 that is triggered based on the UE sending a NACK in the ACK / NACK bits to the base station, sending a threshold number of NACK bits to the base station, or sending all NACK bits to the base station. The SRS 502 may be used by the base station to select different beams for retransmission of the PDSCH 508. The SRS resources (e.g., 504a-504b) may be reserved resources associated with ACK / NACK transmissions (e.g., with a short offset from the ACK / ACK transmissions (e.g., 506a-506b)) rather than being dynamically activated / scheduled based on the HARQ feedback 506a.

[0098] If the UL transmission (e.g., PUCCH / PUSCH) corresponds to HARQ feedback 506a, the SRS 502 may be sent with reduced latency on the reserved resources 504a for CC and / or subband reselection by the base station. For example, the SRS 502 may be sent on different CCs or subbands for the base station to determine different beams to be used for retransmission of the PDSCH 508. Since the SRS resources may be wideband resources, the SRS 502 may be sent on multiple CCs (e.g., CC1-CC4) for the base station to estimate / measure multiple CCs and determine different CCs or subbands to be selected for retransmission of the PDSCH 508.

[0099] If the ACK / NACK bits of the HARQ feedback do not satisfy the NACK triggering protocol, the transmission of SRS 502 may not occur on the reserved resources 504b, and the reserved resources 504a may be used for a different purpose. Therefore, by using the ACK / NACK bits of the HARQ feedback 506a to trigger the transmission of SRS 502, rather than scheduling SRS 502 after each ACK / NACK 506a-506b, interference can be reduced based on reducing the number of SRS transmissions when the PDSCH is successfully received. UL resources can be saved by using SRS 502 to indicate ACK / NACK (e.g., DTX of SRS 502 can indicate ACK, while transmission of SRS 502 can indicate at least one NACK).

[0100] Figure 6 Shows something like Figure 5 An example of where CSI-RS transmission and CSI reporting may be triggered by at least one NACK. In response to an indication of a decoding failure of the data transmission, the CSI-RS may be activated on pre-scheduled resources on the candidate CC.

[0101] Diagram 600 shows a second example of NACK triggered communication, where CSI-RS transmission 602 from the base station may be triggered by an ACK / NACK bit of HARQ feedback 604. For example, transmission of CSI-RS 602 from the base station and measurement of the CSI-RS by the UE may be triggered based on the UE sending a NACK in the ACK / NACK bits to the base station, sending a threshold number of NACK bits to the base station, or sending all NACK bits to the base station.

[0102] When NACK / DTX is sent / received for a previously failed transmission, CSI-RS resources and / or CSI reporting resources may be implicitly activated on a candidate CC. In certain aspects, pre-scheduled resources may be activated based on an indication from the UE to the base station when the current CC quality (e.g., SINR or RSRP) is below a threshold, which may be configured by the base station. As described herein, if a resource is not activated, the corresponding time / frequency resource may be canceled or reassigned to another UE.

[0103] In certain aspects, the reference signal may be configured with a beam scanning pattern on a candidate CC, where the SRS / CSI-RS is transmitted / received via different beam pair links. For example, the resources may be part of a shared (e.g., common) resource pool for multiple UEs. Thus, during different periods, different UEs may use resources (e.g., for receiving CSI-RS) based on the UE performing channel measurements due to reduced signal quality of the UE's current CC.

[0104] For example, the HARQ feedback 604 may activate a CSI-RS resource 606 for transmitting the CSI-RS 602, while the ACK may not activate the CSI-RS resource 606. The transmitted CSI-RS 602 may be measured by the UE, and the UE may indicate corresponding information to the base station. For example, the UE may generate a quality report 608 based on the measured CSI-RS 602 triggered by the ACK / NACK bit of the HARQ feedback 604, and send the quality report 608 to the base station on the UL resource 610. Based on the indicated quality report 608, the base station may select parameters, such as a CC (e.g., CC 3), for transmitting the PDSCH 612. In some examples, the PDSCH 612 may be a retransmission of the PDSCH 614.

[0105] To select a CC for transmitting PDSCH 612, the quality of the CC may be determined based on CSI-RS measurements (e.g., if the cycle duration is long). If quality information for the serving CC is being carried with HARQ feedback 604 (e.g., based on SPS DMRS on FR2), CSI-RS 602 may be transmitted on a non-serving CC. If HARQ feedback 604 does not carry quality information for the serving CC, CSI-RS 602 may be transmitted on both FR1 and FR2. To reduce overhead, CSI-RS 602 and corresponding UL resources 610 for quality reporting 608 may be preconfigured, but activated after DTX / NACK (e.g., HARQ feedback 604) is transmitted / received for a previous transmission (e.g., PDSCH 614). If ACK is transmitted / received, CSI-RS 602 and corresponding UL resources 610 may be deactivated. In some examples, NACK-triggered CSI-RS 602 may reduce DCI and scheduling offsets compared to DCI-based CSI-RS, which may be at least greater than a beam switching delay threshold for beam scanning-based CSI-RS transmission on FR2.

[0106] Diagram 700 illustrates a third example of ACK / NACK triggered communications, where a relay UE 706a / 706b (e.g., UE 2 and / or UE 3) or other sidelink device may retransmit a PDSCH from a base station 702 to a target UE 704 (e.g., UE1) and / or relay ACK / NACK feedback from the target UE 704 to the base station 702. In various examples, the relay UE 706a / 706b may be a sidelink UE or a base station that relays communications based on a trigger in an ACK / NACK bit of HARQ feedback received from the target UE 704. For example, the relay UE may retransmit one or more PDSCH transmissions to the target UE 704, triggered based on the target UE 704 sending a NACK in the ACK / NACK bits to the base station, sending a threshold number of NACK bits to the base station, or sending all NACK bits to the base station.

[0107] At 721, the target UE 704 may fail to receive a semi-persistent scheduling (SPS) PDSCH in an initial transmission for the target UE 704. However, the SPS PDSCH may be received by one or more of the relay UEs 706a-706b.

[0108] Thus, the target UE 704 may send at least one NACK in the ACK / NACK bits to the base station 702 for the initial transmission, which may not be received by the base station 702, but may be received by one or more relay UEs 706a-706b. Based on the NACK, the target UE 704, the relay UEs 706a-706b and / or the base station 702 may determine that the configured resources (which were previously configured) are activated for retransmitting the PDSCH to the target UE 704.

[0109] At 723, the base station 702 may retransmit the PDSCH on the configured resources, which may again not be received by the target UE 704, but may be received by the relay UEs 706a-706b. Thus, one or more of the relay UEs 706a-706b may retransmit the retransmitted PDSCH received from the base station 702 to the target UE 704 on the configured resources. In various examples, one or more relay UEs 706a-706b may retransmit the PDSCH received via the initial transmission. The PDSCH resources may be spatial division multiplexed (SDM), frequency division multiplexed (FDM), or time division multiplexed (TDM) for the relay UEs 706a-706b to retransmit the PDSCH.

[0110] If the retransmission from the relay UE 706a-706b is decoded by the target UE 704 at 723, then at 725, the target UE 704 may send an ACK on the configured resources (e.g., PUCCH). In some cases, the ACK may not be received by the base station 702, but may be received by one or more of the relay UEs 706a-706b. Therefore, if the relay UE 706a-706b receives the ACK, then at 727, the ACK may be relayed to the base station 702 on the configured resources. At 727, the relay UE may optionally relay feedback based on whether the base station 702 or the relay UE 706a-706b receives an ACK / NACK from the target UE 704 at 725. Although the relay UE 706a-706b may be configured to perform retransmissions, such retransmissions may not occur without a NACK trigger.

[0111] Given a single UL transmission (e.g., PUCCH / PUSCH) may include multiple ACK / NACK bits corresponding to multiple PDSCH transmissions, some bits in the UL transmission may correspond to ACKs and other bits in the UL transmission may correspond to NACKs. That is, a single UL transmission (which may include one bit for each of the multiple PDSCH transmissions) may have one or more ACK bits and / or one or more NACK bits. Therefore, the triggering mechanism for the SRS transmission from the UE in Figure 500, the CSI-RS transmission from the base station in Figure 600, and the sidelink retransmission from the relay UE in Figure 700 may be based on the ACK / NACK of a single UL transmission.

[0112] Figure 8 800 is a flow chart of a method of wireless communication. The method may be performed by a UE (e.g., UE 104, 402, 704; apparatus 1402), which may include a memory 360 and may be the entire UE 104, 402, 704 or a component of the UE 104, 402, 704, such as the TX processor 368, the RX processor 356 and / or the controller / processor 359. The method may enable the UE 104, 402, 704 to exchange communications with the base station 102, 180, 404, the apparatus 1502, etc. after multi-bit ACK / NACK feedback.

[0113] At 802, the UE receives a configuration for resources. The resources may be referred to as configured resources. The configured resources may be used for SRS transmission from the UE, for example, as described in conjunction with Figure 5 The configured resources may be used for CSI-RS from the base station and / or CSI reports from the UE, for example, as combined with Figure 6 The configured resources may be used for sidelink retransmissions of one or more PDSCHs, for example, as combined with Figure 7 The reception at 802 may be performed by Fig.14 The receiving component 1430 of the device 1402 is executed.

[0114] At 804, the UE monitors one or more PDSCH transmissions. Figure 4 An example is shown of a UE monitoring a PDSCH transmission 407. In some examples, the PDSCH transmission may be an SPS transmission. Figure 5-7 An additional example of a UE monitoring a PDSCH transmission is shown. The monitoring at 804 may be performed by Fig.14 The monitoring component 1440 of the device 1402 is executed.

[0115] At 806, the UE sends an uplink transmission including HARQ feedback carrying a plurality of NACK or ACK bits for one or more PDSCH transmissions. Figure 4 An example of a UE sending HARQ feedback (eg, including ACK / NACK bits) for multiple PDSCH transmissions is shown. The transmission at 806 may be performed by Fig.14 The sending component 1434 of the device 1402 is executed.

[0116] At 808, the UE sends or receives communications in the configured resources based on a trigger in the HARQ feedback for sending or receiving communications in the configured resources. In some examples, the UE may send one or more SRSs on the configured resources based on a trigger associated with the HARQ feedback, for example, as described in conjunction with Figure 5 In some examples, the UE may receive one or more CSI-RS and send corresponding CSI-RS reports on the configured resources based on a trigger associated with the HARQ feedback, for example, as described in conjunction with Figure 6 In some examples, the UE may monitor retransmissions of the PDSCH from a relay UE in communication with the base station based on a trigger associated with the HARQ feedback, for example, as described in conjunction with Figure 7 The sending or receiving at 808 may be performed by Fig.14 The transmitting component 1434, the receiving component 1430 and / or the cellular RF transceiver 1422 of the device 1402 are executed.

[0117] Fig. 9 Flowchart 900 of a method of wireless communication. The method may be performed by a UE (e.g., UE 104, 402, 704; apparatus 1402), which may include a memory 360 and may be the entire UE 104, 402, 704 or a component of the UE 104, 402, 704, such as the TX processor 368, the RX processor 356, and / or the controller / processor 359. The method may enable the UE 104, 402, 704 to exchange communications with the base station 102, 180, 404, the apparatus 1502, etc. after multi-bit ACK / NACK feedback.

[0118] At 902, the UE receives a configuration for resources. The resources may be referred to as configured resources. The configured resources may be used for SRS transmission from the UE, for example, as described in conjunction with Figure 5 The configured resources may be used for CSI-RS from the base station and / or CSI reports from the UE, for example, as combined with Figure 6 The configured resources may be used for sidelink retransmissions of one or more PDSCHs, for example, as combined with Figure 7 The receiving at 902 may be performed by Fig.14 The receiving component 1430 of the device 1402 is executed.

[0119] At 904, the UE monitors one or more PDSCH transmissions. Figure 4 An example is shown of a UE monitoring a PDSCH transmission 407. In some examples, the PDSCH transmission may be an SPS transmission. Figure 5-7 An additional example of a UE monitoring a PDSCH transmission is shown. The monitoring at 904 may be performed by Fig.14 The monitoring component 1440 of the device 1402 is executed.

[0120] At 908, the UE sends an uplink transmission including HARQ feedback carrying a plurality of NACK or ACK bits for one or more PDSCH transmissions. Figure 4 An example of a UE sending HARQ feedback (eg, including ACK / NACK bits) for multiple PDSCH transmissions is shown. The transmission at 908 may be performed by Fig.14 The sending component 1434 of the device 1402 is executed.

[0121] At 910, the UE determines a trigger in the HARQ feedback for sending or receiving communications in the configured resources. The trigger may be based on at least one NACK or ACK bit of a plurality of NACK or ACK bits of the HARQ feedback corresponding to a NACK bit. The trigger may be based on each ACK / NACK bit of the HARQ feedback corresponding to a NACK bit. The trigger may be based on the percentage of NACK bits of a plurality of NACK or ACK bits of the HARQ feedback exceeding a first threshold. The trigger may be based on at least one NACK or ACK bit of a plurality of NACK or ACK bits of the HARQ feedback corresponding to an ACK bit. The trigger may be based on each ACK / NACK bit of the HARQ feedback corresponding to an ACK bit. The trigger may be based on the percentage of ACK bits of a plurality of NACK or ACK bits of the HARQ feedback exceeding a second threshold. The first threshold and the second threshold may be the same or may be different. The determination at 910 may be performed by Fig.14 The determining component 1442 of the device 1402 is executed.

[0122] For example, the threshold of the NACK bit or the ACK bit may be a fixed and / or predefined threshold. In some examples, the UE may receive the threshold from the base station in one or more of the DCI, MAC-CE, or RRC messages. In some examples, the UE may signal the threshold to the base station in at least one of the UCI, MAC-CE, or RRC messages. In some examples, the UE may determine a trigger for sending or receiving communications in the configured resources based on the HARQ-ACK codebook type.

[0123] At 912, the UE sends or receives communications in the configured resources based on the trigger in the HARQ feedback. In some examples, the UE may send one or more SRSs on the configured resources based on the trigger associated with the HARQ feedback, for example, as described in conjunction with Figure 5 In some examples, the UE may receive one or more CSI-RS and send corresponding CSI-RS reports on the configured resources based on a trigger associated with the HARQ feedback, for example, as described in conjunction with Figure 6 In some examples, the UE may monitor retransmissions of the PDSCH from a relay UE in communication with the base station based on a trigger associated with the HARQ feedback, for example, as described in conjunction with Figure 7 The sending or receiving at 912 may be performed by Fig.14 The transmitting component 1434, the receiving component 1430 and / or the cellular RF transceiver 1422 of the device 1402 are executed.

[0124] The transmission or reception of the communication at 912 may also be based on the priority level of the uplink resource (e.g., PUCCH or PUSCH) in which the HARQ feedback is sent. For example, if the PUSCH or PUCCH carrying the ACK / NACK bits has a high priority, the HARQ feedback may trigger the UE to monitor retransmissions or CSI-RS or send SRS or CSI reports, and if the PUSCH / PUCCH carrying the NACK / NACK bits has a low priority, the monitoring of retransmissions / CSI-RS or the transmission of SRS / CSI reports may be skipped.

[0125] In some examples, as shown at 906, the UE can determine the priority of the configuration of the uplink transmission in which to send HARQ feedback based on at least one of the uplink resource configurations. Figure 4 An example of a UE determining a priority of an UL transmission including HARQ feedback associated with multiple ACK / NACKs is shown. The determination at 906 may be performed by Fig.14 The determining component 1442 of the device 1402 is executed.

[0126] In some examples, as shown at 907, the UE may receive an indication of the priority of the uplink transmission in which the HARQ feedback is sent based on at least one of the uplink resource configurations in the DCI associated with the one or more PDSCH transmissions. The reception at 907 may be performed by Fig.14 The receiving component 1430 of the device 1402 is executed.

[0127] The priority may be a fixed and / or predefined priority. In some examples, the UE may receive the priority from the base station in one or more of a DCI, a MAC-CE, or an RRC message. In some examples, the UE may signal the priority to the base station in at least one of uplink control information, a MAC-CE, or an RRC message.

[0128] Fig.10 1000 is a flow chart of a method of wireless communication. The method may be performed by a base station (e.g., base station 102, 180, 404, 702; apparatus 1502, etc.), which may include a memory 376 and may be the entire base station 102, 180, 404, 702 or a component of the base station 102, 180, 404, 704, 702, such as the TX processor 316, the RX processor 370 and / or the controller / processor 375.

[0129] At 1002, the base station sends a configuration of resources associated with one or more physical PDSCH transmissions. The resources may be referred to as configured resources. The configured resources may be used for SRS transmissions from a UE, for example, as described in conjunction with Figure 5 The configured resources may be used for CSI-RS from the base station and / or CSI reports from the UE, for example, as combined with Figure 6 The configured resources may be used for sidelink retransmissions of one or more PDSCHs, for example, as combined with Figure 7 The transmission at 1002 may be performed by Fig.15 The sending component 1534 of the device 1502 is executed.

[0130] At 1004, the base station receives an uplink transmission from the UE including HARQ feedback carrying a plurality of NACK or ACK bits for one or more PDSCH transmissions. Figure 4 1004 may be received by Fig.15 The receiving component 1530 of the device 1502 is executed.

[0131] At 1006, the base station sends CSI-RS or receives SRS in the configured resources based on the trigger in the HARQ feedback for sending CSI-RS or receiving SRS in the configured resources. The trigger may be that at least one NACK or ACK bit in a plurality of NACK or ACK bits of the HARQ feedback corresponds to a NACK bit. The trigger may be that each ACK / NACK bit in the ACK / NACK bits of the HARQ feedback corresponds to a NACK bit. The trigger may be that the percentage of NACK bits in a plurality of NACK or ACK bits of the HARQ feedback exceeds a first threshold. The trigger may be that at least one NACK or ACK bit in a plurality of NACK or ACK bits of the HARQ feedback corresponds to an ACK bit. The trigger may be that each ACK / NACK bit in the ACK / NACK bits of the HARQ feedback corresponds to an ACK bit. The trigger may be that the percentage of ACK bits in a plurality of NACK or ACK bits of the HARQ feedback exceeds a second threshold. The first threshold and the second threshold may be the same or may be different.

[0132] The base station may receive one or more SRS on the configured resources based on a trigger associated with the HARQ feedback, for example, as combined with Figure 5 The base station may use SRS to improve downlink transmission to the UE, for example, the downlink transmission may include a retransmission of at least one of the one or more PDSCHs. For example, the base station may use SRS to perform fast CC reselection. The base station may send one or more CSI-RS on the configured resources based on a trigger associated with the HARQ feedback and receive a corresponding CSI-RS report, for example, as described in conjunction with Figure 5 The base station may use the CSI report to improve downlink transmission to the UE, for example, the downlink transmission may include a retransmission of at least one of the one or more PDSCHs. For example, the base station may use the CSI report to perform fast CC reselection. The transmission or reception at 1006 may be performed by Fig.15 Executed by the cellular RF transceiver 1536 of the device 1502.

[0133] Fig.11 1100 is a flow chart of a method of wireless communication. The method may be performed by a base station (e.g., base station 102, 180, 404, 702; apparatus 1502, etc.), which may include a memory 376 and may be the entire base station 102, 180, 404, 702 or a component of the base station 102, 180, 404, 704, 702, such as the TX processor 316, the RX processor 370 and / or the controller / processor 375.

[0134] At 1102, the base station sends a configuration of resources associated with one or more physical PDSCH transmissions. The configured resources may be used for SRS transmissions from the UE, for example, as combined with Figure 5 The configured resources may be used for CSI-RS from the base station and / or CSI reports from the UE, for example, as combined with Figure 6 The configured resources may be used for sidelink retransmissions of one or more PDSCHs, for example, as combined with Figure 7 The sending at 1102 can be done by Fig.15 The sending component 1534 of the device 1502 is executed.

[0135] At 1108, the base station receives an uplink transmission from the UE including HARQ feedback carrying a plurality of NACK or ACK bits for one or more PDSCH transmissions. Figure 4 1108. The base station may send one or more PDSCH transmissions to the UE. In some examples, the PDSCH transmission may be an SPS transmission. The reception at 1108 may be performed by Fig.15 The receiving component 1530 of the device 1502 is executed.

[0136] At 1110, the base station determines a trigger in the HARQ feedback for sending CSI-RS or receiving SRS in the configured resources. The trigger may be based on at least one NACK or ACK bit of multiple NACK or ACK bits of the HARQ feedback corresponding to a NACK bit. The trigger may be based on each ACK / NACK bit of the ACK / NACK bits of the HARQ feedback corresponding to a NACK bit. The trigger may be based on the percentage of NACK bits of multiple NACK or ACK bits of the HARQ feedback exceeding a first threshold. The trigger may be based on at least one NACK or ACK bit of multiple NACK or ACK bits of the HARQ feedback corresponding to an ACK bit. The trigger may be based on each ACK / NACK bit of the ACK / NACK bits of the HARQ feedback corresponding to an ACK bit. The trigger may be based on the percentage of ACK bits of multiple NACK or ACK bits of the HARQ feedback exceeding a second threshold. The first threshold and the second threshold may be the same or may be different. The determination at 1110 may be determined by Fig.15 The trigger component 1532 of the device 1502 is executed.

[0137] For example, the threshold of the NACK bit or the ACK bit may be a fixed and / or predefined threshold. In some examples, the base station may send the threshold to the UE in one or more of the DCI, MAC-CE, or RRC messages. In some examples, the base station may receive the threshold from the UE in at least one of the UCI, MAC-CE, or RRC messages. In some examples, the base station may determine a trigger for sending or receiving communications in the configured resources based on the HARQ-ACK codebook type.

[0138] At 1112, the base station sends CSI-RS or receives SRS in the configured resources based on the trigger in the HARQ feedback. The base station may receive one or more SRS on the configured resources based on the trigger associated with the HARQ feedback, for example, as combined with Figure 5 The base station may use SRS to improve downlink transmission to the UE, for example, the downlink transmission may include a retransmission of at least one of the one or more PDSCHs. For example, the base station may use SRS to perform fast CC reselection. The base station may send one or more CSI-RS on the configured resources based on a trigger associated with the HARQ feedback and receive a corresponding CSI-RS report, for example, as described in conjunction with Figure 5 The base station may use the CSI report to improve downlink transmission to the UE, for example, the downlink transmission may include a retransmission of at least one of the one or more PDSCHs. For example, the base station may use the CSI report to perform fast CC reselection. The transmission or reception at 1112 may be performed by Fig.15 Executed by the cellular RF transceiver 1536 of the device 1502.

[0139] The transmission or reception occurring at 1112 may also be based on the priority level of the uplink resource (e.g., PUCCH or PUSCH) in which the HARQ feedback is received. For example, if the PUSCH or PUCCH carrying the ACK / NACK bits has a high priority, the HARQ feedback may trigger the base station to monitor the SRS or transmit the CSI-RS, and if the PUSCH / PUCCH carrying the NACK / NACK bits has a low priority, the monitoring of the SRS or the transmission of the CSI-RS may be skipped.

[0140] The priority of the uplink transmission in which the HARQ feedback is received may be configured based on, for example, at least one of the uplink resource configurations and may be determined by the base station at 1104. The determination at 1104 may be made by Fig.15The receiving component 1530 of the apparatus 1502 in the embodiment is executed. As shown at 1106, the base station can send an indication of the priority of the uplink transmission in which the HARQ feedback is received based on the uplink resource configuration in the DCI associated with the one or more PDSCH transmissions.

[0141] The priority may be a fixed and / or predefined priority. For example, at 1106, the base station may send the priority to the UE in one or more of a DCI, a MAC-CE, or an RRC message. In some examples, at 1106, the base station may receive the priority from the UE in at least one of a UCI, a MAC-CE, or an RRC message. The sending or receiving at 1106 may be performed by Fig.15 Executed by the cellular RF transceiver 1536 of the device 1502.

[0142] In some examples, the base station may receive an uplink transmission including HARQ feedback for one or more PDSCH transmissions from a relay UE in communication with the UE based on a trigger associated with the HARQ feedback, for example, as described in conjunction with Figure 7 The examples in are described.

[0143] Fig.12 1200 is a flow chart of a method of wireless communication. The method may be performed by a first wireless device (e.g., UE 104, sidelink device, relay UE 403, 706a, 706b, apparatus 1602, etc.), which may include a memory 360 / 376 and may be the entire first wireless device or a component of the first wireless device, such as a TX processor 368 / 316, an RX processor 356 / 370, and / or a controller / processor 359 / 375.

[0144] At 1202, a first wireless device receives a configuration of resources associated with one or more PDSCH transmissions from a base station. The resources may be used for sidelink retransmissions, for example, as combined with Figure 4 and / or the examples described in 7. The reception at 1202 may be performed by Fig.16 The receiving component 1630 of the device 1602 is executed.

[0145] At 1204, the first wireless device receives an uplink transmission including HARQ feedback from the second wireless device, the HARQ feedback carrying a plurality of NACK or ACK bits for one or more PDSCH transmissions. Figure 4 1204 may be performed by a relay UE receiving HARQ feedback (eg, including ACK / NACK bits) for multiple PDSCH transmissions from a UE. Fig.16 The receiving component 1630 of the device 1602 is executed.

[0146] At 1206, the first wireless device sends a sidelink retransmission in the configured resources based on a trigger in the HARQ feedback for sending a sidelink retransmission of at least one of the one or more PDSCH transmissions in the configured resources. The first wireless device may be a UE that sends the sidelink retransmission as a relay from the base station to the second wireless device, from the second wireless device to the base station, or from the second wireless device to the base station. For example, the first wireless device may perform Figure 4 and / or Figure 7 In some examples, for example, as combined with Figure 4 and / or Figure 7 As described above, the first wireless device may receive ACK / NACK feedback for the retransmission from the second wireless device and may provide ACK / NACK feedback to the base station. The transmission at 1206 may be performed by Fig.16 The sending component 1634 of the device 1602 in is executed. The trigger may be based on at least one NACK or ACK bit of multiple NACK or ACK bits of HARQ feedback corresponding to a NACK bit. The trigger may be based on each bit of HARQ feedback corresponding to a NACK bit. The trigger may be based on the percentage of NACK bits in multiple NACK or ACK bits of HARQ feedback exceeding a first threshold. The trigger may be based on at least one NACK or ACK bit of multiple NACK or ACK bits of HARQ feedback corresponding to an ACK bit. The trigger may be based on each bit of HARQ feedback corresponding to an ACK bit. The trigger may be based on the percentage of ACK bits in multiple NACK or ACK bits of HARQ feedback exceeding a second threshold. The first threshold and the second threshold may be the same or may be different.

[0147] Fig.13 1300 is a flow chart of a method of wireless communication. The method may be performed by a first wireless device (e.g., UE 104, sidelink device, relay UE 403, 706a, 706b, apparatus 1602, etc.), which may include a memory 360 / 376 and may be the entire first wireless device or a component of the first wireless device, such as a TX processor 368 / 316, an RX processor 356 / 370, and / or a controller / processor 359 / 375.

[0148] At 1302, a first wireless device receives a configuration of resources associated with one or more PDSCH transmissions from a base station. The resources may be used for sidelink retransmissions, for example, as described in conjunction with Figure 4 and / or the examples described in 7. The receiving at 1302 may be performed by Fig.16 The receiving component 1630 of the device 1602 is executed.

[0149] At 1304, the first wireless device receives an uplink transmission including HARQ feedback from a second wireless device, the HARQ feedback carrying a plurality of NACK or ACK bits for one or more PDSCH transmissions. Figure 4 1304 may be performed by a relay UE receiving HARQ feedback (eg, including ACK / NACK bits) for multiple PDSCH transmissions from a UE. Fig.16 The receiving component 1630 of the device 1602 is executed.

[0150] At 1306, the first wireless device determines a trigger in the HARQ feedback for sending a sidelink retransmission in the configured resources. The trigger may be based on at least one NACK or ACK bit of a plurality of NACK or ACK bits of the HARQ feedback corresponding to a NACK bit. The trigger may be based on each ACK / NACK bit of the HARQ feedback corresponding to a NACK bit. The trigger may be based on a percentage of NACK bits of a plurality of NACK or ACK bits of the HARQ feedback exceeding a first threshold. The trigger may be based on at least one NACK or ACK bit of a plurality of NACK or ACK bits of the HARQ feedback corresponding to an ACK bit. The trigger may be based on each ACK / NACK bit of the HARQ feedback corresponding to an ACK bit. The trigger may be based on a percentage of ACK bits of a plurality of NACK or ACK bits of the HARQ feedback exceeding a second threshold. The first threshold and the second threshold may be the same or may be different. The determination at 1306 may be determined by Fig.16 The determining component 1642 of the device 1602 is executed.

[0151] For example, the threshold of the NACK bit or the ACK bit may be a fixed and / or predefined threshold. In some examples, the first wireless device may receive the threshold from the base station in one or more of a DCI, a MAC-CE, or an RRC message. In some examples, the first wireless device may receive the threshold from the second wireless device in at least one of a UCI, a MAC-CE, or an RRC message. In some examples, the UE may determine a trigger for sending or receiving communications in the configured resources based on the HARQ-ACK codebook type.

[0152] At 1308, the first wireless device sends a sidelink retransmission of at least one of the one or more PDSCH transmissions in the configured resources based on the trigger in the HARQ feedback. The first wireless device may be a UE that sends the sidelink retransmission as a relay from the base station to the second wireless device, from the second wireless device to the base station, or from the second wireless device to the base station. For example, the first wireless device may perform Figure 4 and / or Figure 7Various aspects described for a relay UE.

[0153] The sending of the sidelink retransmission at 1308 may also be based on a priority level of the uplink resource (e.g., PUCCH or PUSCH) in which the HARQ feedback is received. For example, if the PUSCH or PUCCH carrying the ACK / NACK bits has a high priority, the HARQ feedback may trigger the sidelink retransmission, and if the PUSCH / PUCCH carrying the ACK / NACK bits has a low priority, the first wireless device may skip the sidelink retransmission.

[0154] In some examples, the first wireless device can receive ACK / NACK feedback for the retransmission from the second wireless device and can provide the ACK / NACK feedback to the base station, for example, as combined with Figure 4 and / or Figure 7 The reception at 1308 may be performed by Fig.16 The sending component 1634 of the device 1602 is executed.

[0155] Fig.141400 is a diagram showing an example of a hardware implementation for an apparatus 1402. The apparatus 1402 is a UE and includes a cellular baseband processor 1404 (also referred to as a modem) coupled to a cellular RF transceiver 1422 and one or more subscriber identity modules (SIM) cards 1420, an application processor 1406 coupled to a secure digital (SD) card 1408 and a screen 1410, a Bluetooth module 1412, a wireless local area network (WLAN) module 1414, a global positioning system (GPS) module 1416, and a power supply 1418. The cellular baseband processor 1404 communicates with the UE 104 and / or the BS 102 / 180 via the cellular RF transceiver 1422. The cellular baseband processor 1404 may include a computer-readable medium / memory. The computer-readable medium / memory may be non-transitory. The cellular baseband processor 1404 is responsible for general processing, including executing software stored on the computer-readable medium / memory. The software, when executed by the cellular baseband processor 1404, causes the cellular baseband processor 1404 to perform the various functions described above. The computer-readable medium / memory may also be used to store data manipulated by the cellular baseband processor 1404 when executing the software. The cellular baseband processor 1404 also includes a receiving component 1430, a communication manager 1432, and a transmitting component 1434. The communication manager 1432 includes one or more of the components shown. The components within the communication manager 1432 may be stored in a computer-readable medium / memory and / or configured as hardware within the cellular baseband processor 1404. The cellular baseband processor 1404 may be a component of the UE 350 and may include at least one of the TX processor 368, the RX processor 356, and the controller / processor 3514 and / or the memory 360. In one configuration, the device 1402 may be a modem chip and include only the baseband processor 1404, and in another configuration, the device 1402 may be the entire UE (e.g., see Figure 3 350) and includes additional modules of device 1402.

[0156] For example, as described in conjunction with 802, 902, and 907, the receiving component 1430 can be configured to receive a configuration for resources and / or receive an indication of a priority for uplink transmissions with HARQ feedback.

[0157] The communication manager 1432 includes a monitor component 1440, e.g., as described in conjunction with 804 and 904, the monitor component 1440 is configured to monitor one or more PDSCH transmissions. The communication manager 1432 also includes a feedback component 1444, the feedback component 1444 is configured to send an uplink transmission including HARQ feedback, the HARQ feedback carrying multiple NACK or ACK bits for one or more PDSCH transmissions. The communication manager 1432 also includes a determination component 1442, e.g., as described in conjunction with 906 and 910, the determination component 1442 is configured to determine a trigger in the HARQ feedback for sending or receiving a communication in the configured resources.

[0158] For example, as described in conjunction with 808 and 912, the transmitting component 1434 and / or the receiving component 1430 can be configured to transmit or receive communications in the configured resources based on a trigger in the HARQ feedback. For example, as described in conjunction with 808 and 912, the cellular RF transceiver 1422 can be configured to transmit or receive communications in the configured resources based on the HARQ feedback.

[0159] The apparatus may include executing Figure 8-9 Each of the blocks in the algorithm in the preceding flowchart has additional components. Therefore, Figure 8-9 Each block in the aforementioned flow chart of can be performed by a component, and the apparatus may include one or more of those components. The component may be one or more hardware components specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium to be implemented by a processor, or some combination thereof.

[0160] The apparatus 1402 (and in particular, the cellular baseband processor 1404) includes: means for receiving a configuration for resources; means for monitoring one or more PDSCH transmissions; means for sending an uplink transmission including HARQ feedback, the HARQ feedback carrying multiple NACK or ACK bits for the one or more PDSCH transmissions; means for determining a trigger in the HARQ feedback for sending or receiving a communication in the configured resources; and means for sending or receiving a communication in the configured resources based on the trigger in the HARQ feedback. The apparatus 1302 may also include means for determining a priority of an uplink transmission in which to send HARQ feedback, for example, as in conjunction with Fig. 9906 or 907 in the above. The above-mentioned means may be one or more components of the above-mentioned components of the device 1402 configured to perform the functions recited by the above-mentioned means. As described above, the device 1502 may include a TX processor 368, an RX processor 356, and a controller / processor 359. Therefore, in one configuration, the above-mentioned means may be a TX processor 368, an RX processor 356, and a controller / processor 359 configured to perform the functions recited by the above-mentioned means.

[0161] Fig.15 1500 is a diagram showing an example of a hardware implementation for an apparatus 1502. The apparatus 1502 is a BS and includes a baseband unit 1504. The baseband unit 1504 can communicate with the UE 104 via a cellular RF transceiver 1536. The baseband unit 1504 may include a computer-readable medium / memory. The baseband unit 1504 is responsible for general processing, including executing software stored on a computer-readable medium / memory. The software, when executed by the baseband unit 1504, causes the baseband unit 1504 to perform the various functions described above. The computer-readable medium / memory can also be used to store data manipulated by the baseband unit 1504 when executing the software. The baseband unit 1504 also includes a receiving component 1530, a communication manager, and a sending component 1534. The communication manager includes one or more of the components shown. The components within the communication manager may be stored in a computer-readable medium / memory and / or configured as hardware within the baseband unit 1504. The baseband unit 1504 may be a component of the base station 310 and may include at least one of the TX processor 316 , the RX processor 370 , and the controller / processor 375 , and / or the memory 376 .

[0162] For example, as described in conjunction with 1002 and 1102, the transmitting component 1534 can be configured to transmit a configuration for resources associated with a PDSCH transmission.

[0163] For example, as described in conjunction with 1004 and 1108, the receiving component 1530 can be configured to receive an uplink transmission including HARQ feedback, the HARQ feedback carrying multiple NACK or ACK bits for one or more PDSCH transmissions. The triggering component 1532 can be configured to determine a trigger in the HARQ feedback for sending or receiving communications in the configured resources, for example, as described in conjunction with 1110. The apparatus can include a CSI-RS component 1537, which is configured to send CSI-RS in the configured resources based on the trigger, for example, as described in conjunction with 1006 and 1112. The apparatus can include an SRS component 1538, which is configured to receive SRS based on the trigger, for example, as described in conjunction with 1006 and 1112. For example, as described in conjunction with 1006 and 1112, the cellular RF transceiver 1536 can be configured to send CSI-RS and / or receive SRS in the configured resources based on the trigger in the HARQ feedback.

[0164] The apparatus may include executing Figure 10-11 Each of the boxes in the algorithm in the above flowchart has additional components. Therefore, Figure 10-11 Each block in the above flowchart may be performed by a component, and the apparatus may include one or more of those components. The component may be one or more hardware components specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium to be implemented by a processor, or some combination thereof.

[0165] The apparatus 1502 (and in particular, the baseband unit 1504) includes: a unit for sending a configuration of resources associated with one or more PDSCH transmissions; a unit for receiving an uplink transmission including HARQ feedback from a UE, the HARQ feedback carrying multiple NACK or ACK bits for one or more PDSCH transmissions; a unit for determining a trigger in the HARQ feedback for sending CSI-RS or receiving SRS in the configured resources; and a unit for sending CSI-RS or receiving SRS in the configured resources based on the trigger in the HARQ feedback. The above-mentioned units can be one or more components of the components of the apparatus 1402 configured to perform the functions recorded by the above-mentioned units. As described above, the apparatus 1402 can include a TX processor 316, an RX processor 370, and a controller / processor 375. Therefore, in one configuration, the above-mentioned units can be a TX processor 316, an RX processor 370, and a controller / processor 375 configured to perform the functions recorded by the above-mentioned units.

[0166] Fig.1616 is a diagram showing an example of a hardware implementation for an apparatus 1602. The apparatus 1602 is a UE and includes a cellular baseband processor 1604 (also referred to as a modem) coupled to a cellular RF transceiver 1622 and one or more subscriber identity modules (SIM) cards 1620, an application processor 1606 coupled to a secure digital (SD) card 1608 and a screen 1610, a Bluetooth module 1612, a wireless local area network (WLAN) module 1614, a global positioning system (GPS) module 1616, and a power supply 1618. The cellular baseband processor 1604 communicates with the UE 104 and / or the BS 102 / 180 via the cellular RF transceiver 1622. The cellular baseband processor 1604 may include a computer-readable medium / memory. The computer-readable medium / memory may be non-transitory. The cellular baseband processor 1604 is responsible for general processing, including executing software stored on the computer-readable medium / memory. The software, when executed by the cellular baseband processor 1604, causes the cellular baseband processor 1604 to perform the various functions described above. The computer-readable medium / memory may also be used to store data manipulated by the cellular baseband processor 1604 when executing the software. The cellular baseband processor 1604 also includes a receiving component 1630, a communication manager 1632, and a transmitting component 1634. The communication manager 1632 includes one or more of the components shown. The components within the communication manager 1632 may be stored in a computer-readable medium / memory and / or configured as hardware within the cellular baseband processor 1604. The cellular baseband processor 1604 may be a component of the UE 350 and may include at least one of the TX processor 368, the RX processor 356, and the controller / processor 356 and / or the memory 360. In one configuration, the device 1602 may be a modem chip and include only the baseband processor 1604, and in another configuration, the device 1602 may be the entire UE (e.g., see Figure 3 350) and includes additional modules of device 1602.

[0167] The receiving component 1630 may be configured to receive, from a base station, a configuration for resources associated with one or more PDSCH transmissions, e.g., as described in conjunction with 1202 and 1302. The apparatus 1602 may also include a feedback component 1640 configured to receive, from a second wireless device, an uplink transmission including HARQ feedback carrying a plurality of NACK or ACK bits for the one or more PDSCH transmissions, e.g., as described in conjunction with 1204 and 1304. The apparatus 1602 may include a determining component 1642 configured to determine a trigger in the HARQ feedback to send a sidelink retransmission in the configured resources, e.g., as described in conjunction with 1306. The apparatus may include a retransmitting component 1644 configured to send a sidelink retransmission of at least one of the one or more PDSCH transmissions in the configured resources based on the trigger in the HARQ feedback, e.g., as described in conjunction with 1206 and 1308.

[0168] The apparatus may include executing Figure 12-13 Each of the blocks in the algorithm in the preceding flowchart has additional components. Therefore, Figure 12-13 Each block in the aforementioned flow chart of can be performed by a component, and the apparatus may include one or more of those components. The component may be one or more hardware components specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium to be implemented by a processor, or some combination thereof.

[0169] In one configuration, the apparatus 1602 (and in particular, the baseband processor 1604) includes: a unit for receiving a configuration of resources associated with one or more PDSCH transmissions from a base station; a unit for receiving an uplink transmission including HARQ feedback from a second wireless device, the HARQ feedback carrying multiple NACK or ACK bits for one or more PDSCH transmissions; a unit for determining a trigger in the HARQ feedback for sending a sidelink retransmission in the configured resources; and a unit for sending a sidelink retransmission of at least one of the one or more PDSCH transmissions in the configured resources based on the trigger in the HARQ feedback. The above-mentioned units can be one or more components of the components of the apparatus 1602 configured to perform the functions recited by the above-mentioned units. As described above, the apparatus 1602 can include a TX processor 368, an RX processor 356, and a controller / processor 359. Therefore, in one configuration, the above-mentioned units can be a TX processor 368, an RX processor 356, and a controller / processor 359 configured to perform the functions recited by the above-mentioned units.

[0170] It is to be understood that the specific order or hierarchy of the blocks in the disclosed process / flowchart is an illustration of an exemplary method. It is to be understood that the specific order or hierarchy of the blocks in the process / flowchart may be rearranged based on design preferences. In addition, some blocks may be merged or omitted. The attached method claims present the elements of the various blocks in an exemplary order and are not intended to be limited to the specific order or hierarchy presented.

[0171] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the claims are not intended to be limited to the various aspects shown herein, but are given the full scope consistent with the textual claims, wherein, unless explicitly stated as such, references to singular elements are not intended to mean "one and only one", but "one or more". Terms such as "if", "when ..." and "while ..." should be interpreted as meaning "under the conditions of ...", rather than meaning a direct temporal relationship or reaction. That is, these phrases (e.g., "when ...") do not mean immediate action in response to the occurrence of an action or during the occurrence of an action, but only mean that the action will occur if the condition is met, without requiring a specific or immediate time constraint for the occurrence of the action. The word "exemplary" is used herein to mean "used as an example, instance or illustration". Any aspect described as "exemplary" herein is not necessarily interpreted as preferred or advantageous over other aspects. Unless otherwise expressly stated, the term "some" refers to one or more. Combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and / or C, and may include multiple A, multiple B, or multiple C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” may be only A, only B, only C, A and B, A and C, B and C, or A and B and C, wherein any such combination may include one or more members of A, B, or C. All structural and functional equivalents of the elements of the various aspects described throughout the present disclosure that are known or later become known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module,” “mechanism,” “element,” “device,” etc. may not be substitutes for the word “unit.” Thus, no claim element should be construed as a functional unit unless the element is explicitly recited using the phrase “a means for….”

[0172] The following examples are merely illustrative, and aspects thereof may be combined with aspects of other examples or teachings described herein, but are not limited thereto.

[0173] Aspect 1 is a method of wireless communication at a user equipment (UE), comprising: receiving a configuration for resources; monitoring one or more PDSCH transmissions; sending an uplink transmission including a hybrid automatic repeat request (HARQ) feedback, the HARQ feedback carrying multiple negative acknowledgment (NACK) or acknowledgment ACK bits for one or more PDSCH transmissions; determining a trigger in the HARQ feedback for sending or receiving communication in the resource; and sending or receiving communication in the resource based on the trigger in the HARQ feedback.

[0174] In aspect 2, the method according to aspect 1 further includes: triggering at least one NACK or ACK bit of a plurality of NACK or ACK bits based on HARQ feedback corresponds to a NACK bit.

[0175] In aspect 3, the method according to aspect 1 further includes: triggering each NACK or ACK bit of a plurality of NACK or ACK bits based on HARQ feedback corresponds to a NACK bit.

[0176] In aspect 4, the method according to aspect 1 further includes: triggering is based on a percentage of NACK bits among a plurality of NACKs or ACK bits fed back by HARQ exceeding a threshold.

[0177] In aspect 5, the method according to aspect 4 further includes: the threshold is at least one of a fixed threshold or a predefined threshold.

[0178] In aspect 6, the method according to aspect 4 or 5 further includes: the UE receiving a threshold from the base station in one or more of downlink control information (DCI), medium access control-control element (MAC-CE) or radio resource control (RRC) messages.

[0179] In aspect 7, the method according to any of aspects 4-6 further includes: the UE signals the threshold to the base station in at least one of uplink control information, medium access control-control element (MAC-CE) or radio resource control (RRC) message.

[0180] In aspect 8, the method according to any of aspects 1-7 further includes: the UE determining a trigger for sending or receiving communication in the resource based on a HARQ acknowledgement (ACK) (HARQ-ACK) codebook type.

[0181] In aspect 9, the method according to any of aspects 1-8 also includes: determining a preconfigured priority of an uplink transmission in which HARQ feedback is sent based on at least one uplink resource configuration in the uplink resource configuration, wherein the sending or receiving in the resource is also based on the priority of the uplink transmission in which HARQ feedback is sent.

[0182] In aspect 10, the method according to any of aspects 1-9 also includes: receiving an indication of the priority of the uplink transmission in which the HARQ feedback is sent based on at least one uplink resource configuration in the downlink control information (DCI) associated with one or more PDSCH transmissions, wherein the sending or receiving in the resource is also based on the priority of the uplink transmission in which the HARQ feedback is sent.

[0183] In aspect 11, the method according to any of aspects 1-10 also includes: the priority is at least one of a fixed priority or a predefined priority, wherein the transmission or reception in the resource is also based on the priority of the uplink transmission in which the HARQ feedback is sent.

[0184] In aspect 12, the method according to any of aspects 1-11 also includes: the UE receives a priority from the base station in one or more of downlink control information (DCI), medium access control-control element (MAC-CE) or radio resource control (RRC) messages, wherein the sending or receiving in the resource is also based on the priority of the uplink transmission in which the HARQ feedback is sent.

[0185] In aspect 13, the method according to any of aspects 1-12 also includes: the UE signals the priority to the base station in at least one of uplink control information, medium access control-control element (MAC-CE) or radio resource control (RRC) message, wherein the sending or receiving in the resource is also based on the priority of the uplink transmission in which the HARQ feedback is sent.

[0186] In aspect 14, the method according to any of aspects 1-13 further includes: the UE sending one or more sounding reference signals (SRS) on the resources based on a trigger associated with the HARQ feedback.

[0187] In aspect 15, the method according to any of aspects 1-14 further includes: the UE receives one or more channel state information (CSI)-reference signals (RS) (CSI-RS) on resources based on a trigger associated with HARQ feedback and sends a corresponding CSI-RS report.

[0188] In aspect 16, the method according to any of aspects 1-15 further includes: the UE monitoring a physical downlink shared channel (PDSCH) retransmission from a relay UE in communication with the base station based on a trigger associated with the HARQ feedback.

[0189] In aspect 17, the method according to any of aspects 1-16 further comprises: triggering at least one NACK or ACK bit of the plurality of NACK or ACK bits based on HARQ feedback corresponds to an ACK bit.

[0190] In aspect 18, the method according to any of aspects 1-17 further comprises: triggering each NACK or ACK bit of a plurality of NACK or ACK bits based on HARQ feedback corresponds to an ACK bit.

[0191] In aspect 19, the method according to any of aspects 1-18 further comprises: the triggering is based on a percentage of ACK bits in a plurality of NACK or ACK bits fed back by the HARQ exceeding a threshold.

[0192] Aspect 20 is a device comprising one or more processors and one or more memories storing instructions in electronic communication with one or the processors, the instructions executable by the one or more processors to cause the device to implement the method as in any of aspects 1-19.

[0193] Aspect 21 is a system or an apparatus, comprising means for implementing the method in any of Aspects 1-19 or implementing the apparatus in any of Aspects 1-19.

[0194] Aspect 22 is a non-transitory computer-readable medium storing instructions, the instructions being executable by one or more processors to cause the one or more processors to implement the method as in any of aspects 1-19.

[0195] Aspect 23 is a method of wireless communication at a base station, comprising: sending a configuration for resources associated with one or more physical downlink shared channel (PDSCH) transmissions; receiving an uplink transmission including a hybrid automatic repeat request (HARQ) feedback from a user equipment (UE), the HARQ feedback carrying multiple negative acknowledgment (NACK) or acknowledgment ACK bits for one or more PDSCH transmissions; determining a trigger in the HARQ feedback for sending a channel state information reference signal (CSI-RS) or receiving a sounding reference signal (SRS) in the resource; and sending the CSI-RS or receiving the SRS in the resource based on the trigger in the HARQ feedback.

[0196] In aspect 24, the method according to aspect 23 further comprises: triggering at least one NACK or ACK bit of the plurality of NACK or ACK bits based on HARQ feedback corresponds to a NACK bit.

[0197] In aspect 25, the method according to aspect 23 further comprises: triggering each NACK or ACK bit of a plurality of NACK or ACK bits based on HARQ feedback corresponds to a NACK bit.

[0198] In aspect 26, the method according to aspect 23 further comprises: the triggering is based on a percentage of NACK bits among a plurality of NACKs or ACK bits fed back by the HARQ exceeding a threshold.

[0199] In aspect 27, the method according to aspect 26 further comprises: the threshold is at least one of a fixed threshold or a predefined threshold.

[0200] In aspect 28, the method according to any of aspects 26-27 further includes: the base station sending the threshold to the UE in one or more of downlink control information (DCI), medium access control-control element (MAC-CE) or radio resource control (RRC) messages.

[0201] In aspect 29, the method according to any of aspects 26-28 further includes: the base station receiving the threshold from the UE in at least one of uplink control information, medium access control-control element (MAC-CE) or radio resource control (RRC) message.

[0202] In aspect 30, the method according to any of aspects 23-29 further comprises triggering being based on a HARQ acknowledgement (ACK) (HARQ-ACK) codebook type.

[0203] In aspect 31, the method according to any of aspects 23-30 also includes: the priority of the uplink transmission in which the HARQ feedback is received is pre-configured based on at least one uplink resource configuration in the uplink resource configuration, wherein the transmission of CSI-RS or the reception of SRS in the resource is also based on the priority of the uplink transmission in which the HARQ feedback is received.

[0204] In aspect 32, the method according to any of aspects 23-31 also includes: sending an indication of the priority of the uplink transmission in which the HARQ feedback is received based on the uplink resource configuration in the downlink control information (DCI) associated with one or more PDSCH transmissions, wherein the sending of the CSI-RS or the receiving of the SRS in the resources is also based on the priority of the uplink transmission in which the HARQ feedback is received.

[0205] In aspect 33, the method according to any of aspects 23-32 also includes: the priority is at least one of a fixed priority or a predefined priority, wherein the transmission of CSI-RS or the reception of SRS in the resource is also based on the priority of the uplink transmission in which the HARQ feedback is received.

[0206] In aspect 34, the method according to any of aspects 23-33 also includes: the base station sends a priority to the UE in one or more of downlink control information (DCI), medium access control-control element (MAC-CE) or radio resource control (RRC) messages, wherein the transmission of CSI-RS or the reception of SRS in the resource is also based on the priority of the uplink transmission in which the HARQ feedback is received.

[0207] In aspect 35, the method according to any of aspects 23-34 also includes: the base station receives a priority from the UE in at least one of uplink control information, medium access control-control element (MAC-CE) or radio resource control (RRC) message, wherein the transmission of CSI-RS or the reception of SRS in the resource is also based on the priority of the uplink transmission in which the HARQ feedback is received.

[0208] In aspect 36, the method according to any of aspects 23-35 further comprises the base station receiving one or more SRS on the resources based on a trigger associated with the HARQ feedback.

[0209] In aspect 37, the method according to any of aspects 23-36 further includes: the base station sending one or more CSI-RS on the resources based on a trigger associated with the HARQ feedback and receiving a corresponding CSI-RS report.

[0210] In aspect 38, the method according to any of aspects 23-37 further includes: the base station receiving an uplink transmission including HARQ feedback for one or more PDSCH transmissions from a relay UE in communication with the UE based on a trigger associated with the HARQ feedback.

[0211] In aspect 39, the method according to any of aspects 23-38 further comprises triggering at least one NACK or ACK bit of the plurality of NACK or ACK bits based on HARQ feedback corresponding to an ACK bit.

[0212] In aspect 40, the method according to any of aspects 23-39 further comprises triggering each NACK or ACK bit of a plurality of NACK or ACK bits corresponding to an ACK bit based on HARQ feedback.

[0213] In aspect 41, the method according to any of aspects 23-40 further comprises: the triggering is based on a percentage of ACK bits in a plurality of NACK or ACK bits of the HARQ feedback exceeding a threshold.

[0214] Aspect 42 is a device comprising one or more processors and one or more memories storing instructions in electronic communication with one or the processors, the instructions executable by the one or more processors to cause the device to implement the method as in any of aspects 23-41.

[0215] Aspect 43 is a system or an apparatus, comprising means for implementing a method as in any of Aspects 23-41 or implementing an apparatus as in any of Aspects 23-41.

[0216] Aspect 44 is a non-transitory computer-readable medium storing instructions, the instructions executable by one or more processors to cause the one or more processors to implement the method as in any of aspects 23-41.

[0217] Aspect 45 is a method of wireless communication at a first wireless device, comprising: receiving a configuration of resources associated with one or more physical downlink shared channel (PDSCH) transmissions from a base station; receiving an uplink transmission including a hybrid automatic repeat request (HARQ) feedback from a second wireless device, the HARQ feedback carrying multiple negative acknowledgement (NACK) or acknowledgement (ACK) bits for one or more PDSCH transmissions; determining a trigger in the HARQ feedback for sending a sidelink retransmission in the resource; and sending a sidelink retransmission of at least one of the one or more PDSCH transmissions in the resource based on the trigger in the HARQ feedback.

[0218] In aspect 46, the method according to aspect 45 also includes: the first wireless device is a user equipment (UE), and the UE sends the sidelink retransmission as a relay from the base station to the second wireless device or from the second wireless device to the base station or from the second wireless device to the base station.

[0219] In aspect 47, the method according to aspect 45 or aspect 46 further comprises: triggering at least one NACK or ACK bit of a plurality of NACK or ACK bits based on HARQ feedback corresponds to a NACK bit.

[0220] In aspect 48, the method according to aspect 45 or aspect 46 further comprises: triggering each NACK or ACK bit of a plurality of NACK or ACK bits based on HARQ feedback corresponds to a NACK bit.

[0221] In aspect 49, the method according to aspect 45 or aspect 46 further comprises: the triggering is based on a percentage of NACK bits among a plurality of NACKs or ACK bits fed back by the HARQ exceeding a threshold.

[0222] In aspect 50, the method according to aspect 39 further includes: receiving at least one of a first threshold percentage of NACK bits, a second threshold percentage of ACK bits, or a priority of uplink transmission from a base station in one or more of downlink control information (DCI), medium access control-control element (MAC-CE), or radio resource control (RRC) messages, wherein the retransmission is also sent in the resource based on the priority of the uplink transmission in which the HARQ feedback is received.

[0223] In aspect 51, the method according to any of aspects 45-50 further comprises: triggering in the HARQ feedback is based on a HARQ-ACK codebook type.

[0224] In aspect 52, the method according to any of aspects 45-49 or 51 also includes: the sidelink retransmission is sent based on the priority of the uplink transmission in which the HARQ feedback is sent, and the priority of the uplink transmission is based on the uplink resource configuration.

[0225] Aspect 53 is a device or apparatus comprising one or more processors and one or more memories storing instructions in electronic communication with one or more processors, the instructions executable by the one or more processors to cause the device to implement a method as in any of aspects 45-42.

[0226] Aspect 54 is a system or an apparatus comprising means for implementing a method as in any of Aspects 45-52 or implementing an apparatus as in any of Aspects 45-52.

[0227] Aspect 55 is a non-transitory computer-readable medium storing instructions, the instructions executable by one or more processors to cause the one or more processors to implement the method as in any of aspects 45-52.

Claims

1. An apparatus for wireless communication at a first wireless device, comprising: Memory; as well as at least one processor coupled to the memory and configured to: receiving, from a base station, a configuration for resources associated with a plurality of physical downlink shared channel (PDSCH) transmissions; receiving an uplink transmission including a hybrid automatic repeat request (HARQ) feedback from a second wireless device, the HARQ feedback carrying a plurality of negative acknowledgement (NACK) or acknowledgement (ACK) bits for the plurality of PDSCH transmissions; and The sidelink retransmission is sent in the resource based on a trigger in the HARQ feedback for sending a sidelink retransmission of at least one of the plurality of PDSCH transmissions in the resource.

2. The device according to claim 1, wherein: The first wireless device is a user equipment UE that sends the sidelink retransmission as a relay from the base station to the second wireless device or from the second wireless device to the base station.

3. The device according to claim 1, wherein: The triggering is based on at least one NACK or ACK bit among the multiple NACK or ACK bits of the HARQ feedback corresponding to a NACK bit, or the triggering is based on at least one NACK or ACK bit among the multiple NACK or ACK bits of the HARQ feedback corresponding to an ACK bit.

4. The device according to claim 1, wherein: The triggering is based on each bit of the HARQ feedback corresponding to a NACK bit, or the triggering is based on each bit of the HARQ feedback corresponding to an ACK bit.

5. The device according to claim 1, wherein: The triggering is based on a first percentage of NACK bits in the HARQ feedback exceeding a first threshold, or the triggering is based on a second percentage of ACK bits in the HARQ feedback exceeding a second threshold.

6. The device according to claim 5, wherein: The memory and the at least one processor are configured to receive at least one of the first threshold, the second threshold or the priority of the uplink transmission from a base station in one or more of downlink control information DCI, medium access control-control element MAC-CE or radio resource control RRC messages.

7. The device according to claim 1, wherein: The trigger in the HARQ feedback is based on a hybrid automatic repeat request-acknowledgement HARQ-ACK codebook type.

8. The device according to claim 1, wherein: The sidelink retransmission is sent based on a priority of the uplink transmission in which the HARQ feedback is sent, and the priority of the uplink transmission is based on an uplink resource configuration.

9. An apparatus for wireless communication at a user equipment UE, comprising: Memory; as well as at least one processor coupled to the memory and configured to: receiving a configuration for a resource; Monitor multiple physical downlink shared channel PDSCH transmissions; sending an uplink transmission including a hybrid automatic repeat request (HARQ) feedback carrying a plurality of negative acknowledgement (NACK) or acknowledgement (ACK) bits for the plurality of PDSCH transmissions; and The communication is sent or received in the resource based on a trigger in the HARQ feedback for sending or receiving the communication in the resource.

10. The device according to claim 9, wherein: The triggering is based on at least one NACK or ACK bit among the multiple NACK or ACK bits of the HARQ feedback corresponding to a NACK bit, or the triggering is based on at least one NACK or ACK bit among the multiple NACK or ACK bits of the HARQ feedback corresponding to an ACK bit.

11. The device according to claim 9, wherein: The triggering is based on each bit of the HARQ feedback corresponding to a NACK bit, or the triggering is based on each bit of the HARQ feedback corresponding to an ACK bit.

12. The device according to claim 9, wherein: The triggering is based on a first percentage of NACK bits in the HARQ feedback exceeding a first threshold, or the triggering is based on a second percentage of ACK bits in the HARQ feedback exceeding a second threshold.

13. The device according to claim 12, wherein: The memory and the at least one processor are configured to: receive at least one of the first threshold, the second threshold or the priority of the uplink transmission from a base station in one or more of downlink control information DCI, medium access control-control element MAC-CE or radio resource control RRC messages, and wherein the sending or receiving of the communication in the resource is also based on the priority of the uplink resource in which the HARQ feedback is sent.

14. The device according to claim 12, wherein: The memory and the at least one processor are configured to: signal the first threshold or the second threshold, or at least one of the priorities of the uplink transmission to the base station in at least one of uplink control information, medium access control-control element MAC-CE or radio resource control RRC message, and wherein the sending or receiving of the communication in the resource is also based on the priority of the uplink resource in which the HARQ feedback is sent.

15. The device according to claim 9, wherein: The at least one processor is also configured to receive an indication of a priority of the uplink transmission in which the HARQ feedback is sent based on an uplink resource configuration in downlink control information DCI associated with the multiple PDSCH transmissions, and wherein the sending or receiving of the communication in the resource is also based on the priority of the uplink resource in which the HARQ feedback is sent.

16. The device according to claim 9, wherein: The triggering in the HARQ feedback for the sending or the receiving of the communication in configured resources is based on a hybrid automatic repeat request-acknowledgement HARQ-ACK codebook type.

17. The device according to claim 9, wherein: The priority of the configuration of the uplink transmission in which the HARQ feedback is sent is based on the uplink resource configuration.

18. The device according to claim 9, wherein: The memory and the at least one processor are configured to send one or more sounding reference signals (SRS) on the resources based on the trigger associated with at least one NACK in the HARQ feedback.

19. The device according to claim 9, wherein: The memory and the at least one processor are configured to receive one or more channel state information CSI-reference signals RSCSI-RS based on the trigger associated with at least one NACK in the HARQ feedback and send corresponding CSI-RS reports on the resources.

20. The device according to claim 9, wherein: The memory and the at least one processor are configured to monitor a retransmission of a physical downlink shared channel (PDSCH) from a relay UE in communication with a base station based on the trigger associated with at least one NACK in the HARQ feedback.

21. An apparatus for wireless communication at a base station, comprising: Memory; as well as at least one processor coupled to the memory and configured to: sending a configuration of resources associated with a plurality of physical downlink shared channel (PDSCH) transmissions; receiving an uplink transmission including a hybrid automatic repeat request (HARQ) feedback from a user equipment (UE), the HARQ feedback carrying a plurality of negative acknowledgement (NACK) or acknowledgement (ACK) bits for the plurality of PDSCH transmissions; and The CSI-RS is sent in the resource or the SRS is received based on a trigger in the HARQ feedback for sending a channel state information-reference signal CSI-RS or receiving a sounding reference signal SRS in the resource.

22. The device according to claim 21, wherein The triggering is based on at least one NACK or ACK bit among the multiple NACK or ACK bits of the HARQ feedback corresponding to a NACK bit, or the triggering is based on at least one NACK or ACK bit among the multiple NACK or ACK bits of the HARQ feedback corresponding to an ACK bit.

23. The device according to claim 21, wherein The triggering is based on each bit of the HARQ feedback corresponding to a NACK bit, or the triggering is based on each bit of the HARQ feedback corresponding to an ACK bit.

24. The device according to claim 21, wherein The triggering is based on a first percentage of NACK bits among the multiple NACK or ACK bits of the HARQ feedback exceeding a first threshold, or the triggering is based on a second percentage of ACK bits among the multiple NACK or ACK bits of the HARQ feedback exceeding a second threshold.

25. The device according to claim 24, wherein: The memory and the at least one processor are configured to: send at least one of the first threshold, the second threshold or the priority of the uplink transmission to the UE in one or more of downlink control information DCI, medium access control-control element MAC-CE or radio resource control RRC messages, and wherein the sending of the CSI-RS or the receiving of the SRS in the resource is also based on the priority of the uplink resource in which the HARQ feedback is sent.

26. The device according to claim 24, wherein: The memory and the at least one processor are configured to: receive at least one of the first threshold, the second threshold or the priority of the uplink transmission from the UE in at least one of uplink control information, medium access control-control element MAC-CE or radio resource control RRC message, and wherein, the sending of the CSI-RS or the receiving of the SRS in the resource is also based on the priority of the uplink resource in which the HARQ feedback is sent.

27. The device according to claim 21, wherein The trigger is based on a hybrid automatic repeat request-acknowledgement HARQ-ACK codebook type.

28. The device according to claim 21, wherein The priority of the uplink transmission in which the HARQ feedback is received is configured based on at least one of the uplink resource configurations, and wherein the sending of the CSI-RS or the receiving of the SRS in the resource is also based on the priority of the uplink resource in which the HARQ feedback is sent.

29. The device according to claim 21, wherein The memory and the at least one processor are configured to, in response to the trigger associated with the HARQ feedback, perform at least one of the following: receiving one or more SRSs on the resource, transmitting one or more CSI-RS on the resource and receiving a corresponding CSI-RS report, or The uplink transmission including the HARQ feedback for the plurality of PDSCH transmissions is received from a relay UE in communication with the UE.

30. A method of wireless communication at a user equipment UE, comprising: receiving a configuration for a resource; Monitor multiple physical downlink shared channel PDSCH transmissions; sending an uplink transmission including a hybrid automatic repeat request (HARQ) feedback carrying a plurality of negative acknowledgement (NACK) or acknowledgement (ACK) bits for the plurality of PDSCH transmissions; and The communication is sent or received in the resource based on a trigger in the HARQ feedback for sending or receiving the communication in the resource.

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