HARQ retransmission termination based on lost redundancy version

Abstract

The present disclosure provides systems, devices, apparatuses and methods for terminating HARQ retransmissions, including computer programs encoded on storage media. A wireless receiver may determine that a transmission of a first TB based on a first redundancy version has not been received from a wireless transmitter. Based on the determination, the wireless receiver may send a HARQ ACK to the wireless transmitter to terminate one or more HARQ retransmissions associated with different redundancy versions of the first TB.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 018,429, filed on April 30, 2020, entitled “HARQ Redundancy Version Decode,” and U.S. Patent Application No. 17 / 242,852, filed on April 28, 2021, entitled “HARQ Retransmission Termination Based on Lost Redundancy Version,” both of which are expressly incorporated herein by reference in their entireties. Technical Field

[0003] The present disclosure relates generally to communication systems, and more particularly, to hybrid automatic repeat request (HARQ) retransmission termination based on lost redundancy versions (RVs). 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 systems 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 common protocols that enable different wireless devices to communicate at city, national, regional and even global levels. An example telecommunication standard is 5G New Radio (NR). 5GNR is a part of the continuous mobile broadband evolution promulgated by the Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the Internet of Things (IoT)) and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communication (mMTC) and ultra-reliable low latency communication (URLLC). Some aspects of 5G NR can be based on 4G Long Term Evolution (LTE) standards. There is a need for further improvements in 5G NR technology. These improvements can also be applied to other multiple access technologies and telecommunication standards that adopt these technologies. Summary of the invention

[0006] A simplified summary of one or more aspects is presented 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 the key or critical elements of all aspects nor to define 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 presented later.

[0007] In a HARQ process, an initial transmission associated with a first redundancy version of a transport block (TB) may be sent to a wireless receiver, followed by one or more retransmissions associated with different redundancy versions of the same TB. For example, the first redundancy version may be RV 0, and the different redundancy versions may be RV 2, RV 3, and RV 1, respectively. In an example, a modulation and coding scheme (MCS) may be indicated to the wireless receiver via RV 0, such that the MCS may not be re-indicated to the wireless receiver via one or more retransmissions associated with RV 2, RV 3, and RV 1. Instead, the different redundancy versions may be associated with a reserved MCS corresponding to the same MCS as the MCS used for RV 0. However, if RV 0 is lost / not determined by the wireless receiver, the reserved MCS corresponding to the MCS of RV 0 may not be determined to decode RV 2, RV 3, and RV 1. As a result, when one or more different redundancy versions cannot be decoded by the wireless receiver due to RV 0 being lost / not determined, continuing to retransmit one or more different redundancy versions to the wireless receiver may be a waste of resources.

[0008] The wireless receiver may be configured to send a HARQ acknowledgement (ACK) to the wireless transmitter when the HARQ transmission / retransmission is successfully received and decoded by the wireless receiver, and to send a negative acknowledgement (NACK) when the HARQ transmission / retransmission is not successfully received and decoded by the wireless receiver. If the wireless transmitter does not receive an ACK or a NACK from the wireless receiver, the wireless transmitter may determine that discontinuous transmission (DTX) has occurred and proceed with retransmission of the next redundancy version (e.g., RV 2). Therefore, if the wireless receiver expects to receive RV 0, but RV 0 is lost / not received, the wireless receiver may unexpectedly receive RV 2. Unexpected reception of RV 2 may indicate to the wireless receiver that RV 0 is lost, which may thereby cause the wireless receiver to send a forced ACK to the wireless transmitter. The forced ACK may terminate additional HARQ retransmissions associated with the remaining different redundancy versions of the TB to reduce resource waste that may be caused by the wireless receiver's inability to decode the additional HARQ retransmissions associated with the remaining different redundancy versions of the TB.

[0009] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus can determine that a transmission of a first TB based on a first redundancy version is not received from a wireless transmitter, and send a HARQ ACK to the wireless transmitter to terminate one or more HARQ retransmissions associated with one or more different redundancy versions of the first TB.

[0010] To achieve the foregoing and related ends, one or more aspects include the features hereinafter fully described 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 a few of the various ways in which the principles of the various aspects may be employed, and this description 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 downlink (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 uplink (UL) channels within a subframe according to various aspects of the present disclosure.

[0016] Figure 3 is a diagram illustrating 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 wireless transmitter and a wireless receiver.

[0018] Figure 5 A diagram corresponding to a channel coding technique is illustrated.

[0019] Figure 6 A diagram associated with a redundancy version (RV) decoding failure is illustrated.

[0020] Figure 7 is a flow chart of a method of wireless communication performed at a wireless receiver.

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

[0022] Fig. 9 is a diagram illustrating an example of a hardware implementation for an example apparatus.

[0023] Fig.10 is a diagram illustrating an example of a hardware implementation for an example apparatus. DETAILED DESCRIPTION

[0024] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configuration in which the concepts described herein may be practiced. For the purpose of providing a thorough understanding of the various concepts, the detailed description includes specific details. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid blurring such concepts.

[0025] Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). 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.

[0026] For example, an element, or any part of an element, or any combination of elements can 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 functionalities described throughout this disclosure. One or more processors in a processing system can execute software. 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, programs, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language or other.

[0027] Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored or encoded on a computer-readable medium as one or more instructions or codes. Computer-readable media include computer storage media. Storage media may be any available medium accessible 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, or other magnetic storage devices, a combination of computer-readable media of the aforementioned types, or any other medium that may be used to store computer executable code in the form of instructions or data structures accessible by a computer.

[0028] Figure 1 1 is a diagram illustrating 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.

[0029] 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 perform one or more of the following functions: delivery of user data, radio 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), subscriber and equipment 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, through the EPC 160 or the core network 190) over a third backhaul link 134 (eg, an X2 interface). The third backhaul link 134 may be wired or wireless.

[0030] Base station 102 can communicate wirelessly with UE 104. Each of base stations 102 can provide communication coverage for a corresponding geographic coverage area 110. There can be overlapping geographic coverage areas 110. For example, a small cell 102' can 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 can be referred to as a heterogeneous network. A heterogeneous network can also include a home evolved Node B (eNB) (HeNB), which can provide services to a restricted group called a closed subscriber group (CSG). The communication link 120 between base station 102 and UE 104 can include an uplink (UL) (also known as a reverse link) transmission from UE 104 to base station 102 and / or a downlink (DL) (also known as a forward link) transmission from base station 102 to UE 104. The communication link 120 can use multiple input and multiple output (MIMO) antenna technology, including spatial multiplexing, beamforming and / or transmit diversity. The communication link may be through one or more carriers. The base station 102 / UE 104 may use a spectrum of up to Y MHz (e.g., 5, 10, 15, 20, 100, 400 MHz, etc.) bandwidth per carrier allocated in a carrier aggregation 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 ​​than for 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, P cell), and the secondary component carrier may be referred to as a secondary cell (SCell, S cell).

[0031] 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, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on IEEE 802.11 standards, LTE, or NR.

[0032] The wireless communication system may also include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 in the 5 GHz unlicensed spectrum via a communication link 154. 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.

[0033] The small cell 102' may operate in licensed and / or unlicensed spectrum. When operating in unlicensed spectrum, the small cell 102' may employ NR and use the same 5 GHz unlicensed spectrum as that 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.

[0034] The electromagnetic spectrum is often subdivided into various levels, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating bands have been identified as frequency range codes FR1 (410MHz-7.125GHz) and FR2 (24.25GHz-52.6GHz). Although portions of FR1 are greater than 6GHz, FR1 is often (interchangeably) referred to as the "sub-6GHz" band in various documents and articles. Similar naming issues sometimes occur with respect to FR2, which is often (interchangeably) referred to as the "millimeter wave" band in documents and articles, although it is different from the extremely high frequency (EHF) band (30GHz 300GHz) identified as the "millimeter wave" band by the International Telecommunication Union (ITU).

[0035] Frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR research has identified the operating bands for these mid-band frequencies as frequency range code FR3 (7.125GHz-24.25GHz). The frequency bands falling within FR3 can inherit the characteristics of FR1 and / or the characteristics of FR2, and therefore the features of FR1 and / or FR2 can be effectively extended to mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operations to above 52.6GHz. For example, three higher operating bands have been identified as frequency range code 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.

[0036] In view of the above, unless otherwise specified, it should be understood that the term "sub-6 GHz" and the like, if used herein, can broadly refer to frequencies that may be below 6 GHz, may be within FR1, or may include mid-band frequencies. In addition, unless otherwise specified, it should be understood that the term "millimeter wave" and the like, if used herein, can broadly refer to frequencies that may include mid-band frequencies, may be within FR2, FR4, FR4-a or FR4-1 and / or FR5, or may be within the EHF band.

[0037] Whether it is a small cell 102' or a large cell (e.g., a macro base station), the base station 102 may include and / or be referred to as an eNB, a g-node B (gNB), or another type of base station. Some base stations (such as gNB 180) may operate in conventional sub-6 GHz spectrum, millimeter wave (mmW) frequencies, and / or near mmW frequencies in communications with UE 104. When gNB 180 operates in mmW or near mmW frequencies, gNB 180 may be referred to as a mmW base station. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 mm and 10 mm. Radio waves in this band may be referred to as millimeter waves. Near mmW may extend downward to a frequency of 3 GHz with a wavelength of 100 mm. The super high frequency (SHF) band extends between 3 GHz and 30 GHz and is also referred to as centimeter waves. Communications using mmW / near mmW radio frequency bands (e.g., 3 GHz 300 GHz) have extremely high path loss and short range. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range. The base station 180 and the UE 104 may each include multiple antennas, such as antenna elements, antenna panels, and / or antenna arrays, that facilitate beamforming.

[0038] The base station 180 may transmit beamformed signals in one or more transmit directions 182' to the UE 104. The UE 104 may receive beamformed signals from the base station 180 in one or more receive directions 182". The UE 104 may also transmit beamformed signals to the base station 180 in one or more transmit directions. The base station 180 may receive beamformed signals from the UE 104 in one or more receive directions. The base station 180 / UE 104 may perform beam training to determine the best receive and transmit directions for each of the base stations 180 / UE 104. The transmit and receive directions of the base station 180 may be the same or different. The transmit and receive directions of the UE 104 may be the same or different.

[0039] 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. In general, the MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are delivered through the serving gateway 166, which itself is connected to the PDN gateway 172. The PDN gateway 172 provides IP address allocation and other functions to the UE. 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), a PS streaming service, and / or other IP services. The BM-SC 170 may provide functionality for MBMS user service provisioning 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 that broadcasts a specific service, and may be responsible for session management (start / stop) and for collecting eMBMS related charging information.

[0040] 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 (UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. In general, the AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are delivered through the UPF 195. The UPF 195 provides IP address allocation and other functions to the UE. 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 PS streaming service, and / or other IP services.

[0041] Base stations may include and / or be referred to as gNBs, Node Bs, eNBs, access points, base transceiver stations, radio base stations, radio transceivers, transceiver functions, basic service sets (BSSs), extended service sets (ESSs), transmit receive points (TRPs), or some other suitable terminology. Base stations 102 provide access points to EPC 160 or core network 190 for UEs 104. Examples of UEs 104 include cellular phones, smart phones, session initiation protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, global positioning systems, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game consoles, tablets, smart devices, wearable devices, vehicles, electric meters, gas pumps, large or small kitchen appliances, healthcare devices, implants, sensors / actuators, displays, or any other similar functional devices. Some of UEs 104 may be referred to as IoT devices (e.g., parking meters, gas pumps, toasters, vehicles, heart monitors, etc.). UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0042] Reference again Figure 1 In some aspects, the wireless receiver may include a hybrid automatic repeat request (HARQ) retransmission termination component 198 configured to determine that a transmission of a first transport block (TB) based on a first redundancy version (RV) was not received from the wireless transmitter; and to send a HARQ acknowledgement (ACK) to the wireless transmitter to terminate one or more HARQ retransmissions associated with one or more different RVs of the first TB. Although the following description may focus on 5GNR, the concepts described herein may be applicable to other similar fields, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

[0043] Figure 2A FIG200 is a diagram illustrating an example of a first subframe within a 5G / NR frame structure. Figure 2B FIG230 is a diagram illustrating an example of DL channels within a 5G / NR subframe. Figure 2C FIG250 is a diagram illustrating an example of a second subframe within a 5G / NR frame structure. Figure 2D280 is a diagram illustrating an example of UL channels within a 5G / NR subframe. The 5G / NR frame structure may be FDD, where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are either dedicated to DL or UL, or the 5G / NR frame structure may be TDD, where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are dedicated to both DL and UL. Figure 2A , Figure 2C In the example provided, the 5G / NR frame structure is assumed to be TDD, subframe 4 is configured with slot format 28 (primarily DL), where D is DL, U is UL, and X is flexible for use between DL / UL, and subframe 3 is configured with slot format 34 (primarily UL). Although subframes 3 and 4 are shown in slot formats 34 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 codewords. The UE is configured with a slot format through a received slot format indicator (SFI) (dynamically through DL control information (DCI), or semi-statically / statically through radio resource control (RRC) signaling). Note that the following description also applies to the 5G / NR frame structure as TDD.

[0044] Other wireless communication technologies may have different frame structures and / or different channels. A frame (10ms) may be divided into 10 equally sized subframes (1ms). Each subframe may include one or more time slots. A subframe may also include mini-slots, which may include 7, 4, or 2 symbols. Each time slot may include 7 or 14 symbols, depending on the time slot configuration. For time slot configuration 0, each time slot may include 14 symbols, and for time slot configuration 1, each time slot may include 7 symbols. The symbols on the DL may be cyclic prefix (CP) OFDM (CP-OFDM) symbols. The symbols on the UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also known as single carrier frequency division multiple access (SC-FDMA) symbols) (for power-limited scenarios; limited to single stream transmission). The number of time slots within a subframe is based on the time slot configuration and parameter set (numerology). For slot configuration 0, different parameter sets μ0 to 5 allow 1, 2, 4, 8, 16 and 32 slots per subframe, respectively. For slot configuration 1, different parameter sets 0 to 2 allow 2, 4 and 8 slots per subframe, respectively. Accordingly, for slot configuration 0 and parameter set μ, there are 14 symbols / slot and 2 μtime slots / subframes. Subcarrier spacing and symbol length / duration are functions of the parameter set. Subcarrier spacing can be equal to 2 μ *15kHz, where μ is parameter set 0 to 5. Thus, parameter set μ=0 has a subcarrier spacing of 15kHz, and parameter set μ=5 has a subcarrier spacing of 480kHz. The symbol length / duration is inversely related to the subcarrier spacing. FIG. 2A to FIG. 2D An example is provided for slot configuration 0 of 14 symbols per slot and parameter set μ = 2 of 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.

[0045] A resource grid may be used to represent a frame structure. Each slot includes a resource block (RB) (also referred to as a physical RB (PRB)) extending 12 consecutive subcarriers. The resource grid is divided into a plurality of resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0046] like Figure 2A As shown, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) (indicated as R x , where 100x is the port number, but it can also be other DM-RS configurations) and a channel state information reference signal (CSI-RS) for channel estimation performed at the UE. RS can also include beam measurement RS (BRS), beam refinement RS (BRRS) and phase tracking RS (PT-RS).

[0047] Figure 2BExamples of various DL channels within a subframe of a frame are illustrated. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. The 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 identity. The 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 radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE may determine the physical cell identifier (PCI). Based on the PCI, the UE may determine the location of the aforementioned DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) may be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block. The MIB provides the number of RBs in the system bandwidth and the system frame number (SFN). The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH (such as a System Information Block (SIB)), and paging messages.

[0048] like Figure 2C As shown, some of the REs carry DM-RS for channel estimation performed at the base station (indicated as R for one particular 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 on the specific PUCCH format used. The UE can send a sounding reference signal (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 teeth. The SRS can be used by the base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0049] Figure 2D An example of various UL channels within a subframe of a frame is illustrated. The PUCCH may be located 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 HARQ ACK / NACK feedback. The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0050] 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 a controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 375 provides RRC layer functionality 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 functionality associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with delivery 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 functionality 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.

[0051] The transmit (TX) processor 316 and receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1 including the physical (PHY) layer may include error detection on 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-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols can then be split 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 from 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.

[0052] 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 the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality 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. Then, the RX processor 356 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 symbol 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. These data and control signals are then provided to the controller / processor 359 which implements layer 3 and layer 2 functionality.

[0053] 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 between transport channels and logical channels, packet reassembly, decryption, header decompression, and control signal processing 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.

[0054] Similar to the functionality described in conjunction with DL transmissions performed by the base station 310, the controller / processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functionality associated with delivery 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 functionality 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.

[0055] Channel estimates derived by the channel estimator 358 from 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.

[0056] 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 the RX processor 370.

[0057] 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.

[0058] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to combine Figure 1 The HARQ retransmission termination component 198 is used to perform various aspects.

[0059] At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 may be configured to combine Figure 1 The HARQ retransmission termination component 198 is used to perform various aspects.

[0060] 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 (such as CDMA systems, TDMA systems, FDMA systems, OFDMA systems, SC-FDMA systems, TD-SCDMA systems, etc. that support communication with multiple users). 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 a continuous evolution, further improvements in mobile broadband remain useful for continuing the advancement of such technology.

[0061] Figure 4 is a call flow diagram 400 illustrating communication between a wireless transmitter 404 and a wireless receiver 402. In a first example, the wireless transmitter 404 may be a base station and the wireless receiver 402 may be a UE. In a second example, the wireless transmitter 404 may be a UE and the wireless receiver 402 may be a base station.

[0062] At 406, the wireless transmitter 404 may transmit a redundancy version (RV) 0 of MAC TB 0 that may have been lost / not received by the wireless receiver 402. At 408, the wireless transmitter 404 may determine that discontinuous transmission (DTX) has occurred based on the wireless transmitter 404 not receiving an ACK or negative acknowledgement (NACK) in response to the transmission associated with RV 0 of MAC TB 0 at 406. Accordingly, at 410, the wireless transmitter 404 may transmit RV 2 of MAC TB 0, which may be the next RV following RV 0. At 410, RV 2 may be received by the wireless receiver 402.

[0063] At 412, the wireless receiver 402 may determine that RV 0 of MAC TB 0 is lost based on receiving RV 2. That is, at 410, RV 2 may be undesirably received by the wireless receiver 402, which may be expecting to receive RV 0 from the wireless transmitter 404. At 414, the wireless receiver 402 may determine whether to terminate retransmissions associated with the remaining RVs of MAC TB 0 (e.g., based on determining at 412 that RV 0 is lost). The determination at 414 of whether to terminate retransmissions associated with the remaining RVs may be based on the wireless receiver 402 being unable to decode the remaining RVs due to unreceived information included in the lost RV 0 transmission. For example, if the lost RV 0 transmission indicates HARQ decoding information (e.g., modulation and coding scheme (MCS) 20), and the subsequent HARQ retransmissions (such as RV 2, RV 3, and / or RV 1) indicate a reserved MCS (e.g., MCS 31), the wireless receiver 202 may not be able to decode the subsequent HARQ retransmissions based on the reserved MCS indicating that the wireless receiver 202 is to reuse the lost RV 0 information for decoding the HARQ retransmissions. In another example, if the RV 0 transmission indicating the HARQ decoding information is lost, but RV 2, RV3, and / or RV 1 also includes complete HARQ decoding information (e.g., MCS, RB, RV, etc.), the wireless receiver 402 may be able to recover from the lost RV 0 transmission and continue decoding the subsequent HARQ retransmissions based on the complete HARQ decoding information also included in RV 2, RV 3, and / or RV 1.

[0064] In the event that the wireless receiver 402 is able to recover from the lost RV 0 transmission and decode the subsequent HARQ retransmissions, the wireless receiver 402 may determine at 414 not to terminate the retransmissions associated with the remaining RVs of the MAC TB and may continue to decode the remaining RVs of the MAC TB. In the event that the wireless receiver 402 is unable to decode the subsequent HARQ retransmissions (e.g., based on the subsequent HARQ retransmissions including the reserved MCS), the wireless receiver 402 may determine at 414 to terminate the retransmissions associated with the remaining RVs of the MAC TB via a forced ACK. The forced ACK may indicate to the wireless transmitter 404 that additional HARQ retransmissions to the wireless receiver 402 are unnecessary and that the wireless transmitter 404 may continue to send the next MAC TB. Since the wireless receiver 402 is unable to decode the retransmissions based on the reserved MCS when RV 0 is lost, terminating the subsequent retransmissions may prevent the wireless transmitter 404 from wasting time and frequency resources on sending the subsequent retransmissions to the wireless receiver 402 and may allow the wireless transmitter 404 to immediately continue to send the next MAC TB to the wireless receiver 402.

[0065] When the wireless receiver 402 determines to terminate retransmissions associated with the remaining RVs of the MAC TB at 414, the wireless receiver 402 may send a forced ACK to the wireless transmitter 404 at 416. At 418, the wireless transmitter 404 may terminate retransmissions associated with the remaining RVs of MAC TB 0 based on receiving the forced ACK from the wireless receiver 402 at 418. At 420, the wireless transmitter 404 may send a different RV 0 associated with the next MAC TB (e.g., MAC TB 1) to the wireless receiver 402.

[0066] Figure 5 500 is a diagram corresponding to a channel coding technique. For channel coding in wireless communications, multiple logic routines, segmentation, cyclic redundancy check (CRC) cascades, etc. may be performed for TBs. In an example, after preparing symbols / bits for encoding, the bits may be provided for sub-block interleaving 508a-508c, bit collection 510, and bit selection 514 (e.g., as an intermediate routine for a physical layer routine). The turbo encoder may execute logic to generate / output system bits 502 and parity bits 504-506, which may be subjected to a forward error correction (FEC) mechanism. The parity bits 504-506 may include a first parity bit 504 and a second parity bit 506.

[0067] The turbo encoder may output three separate data streams for sub-block interleaving 508a-508c. After the systematic bits 502 and the parity bits 504-506 are interleaved separately, the bits may be received by the circular buffer 512 based on first providing all the systematic bits 502 to the circular buffer 512 and then providing the first parity bits 504 and the second parity bits 506 to the circular buffer 512 in an alternating manner. For example, the systematic bits 502 may be first provided to the circular buffer 512 based on a scheme [S1, S2, ..., Sk], followed by providing the parity bits 504-506 based on a scheme [P1(1), P1(2), P2(1), P2(2), ..., Pk(1), Pk(2)], such that the parity bits 504-506 provided to the circular buffer 512 alternate between the first parity bits 504 and the second parity bits 506. Each of the three individually interleaved data streams may be maintained in a circular buffer 512 from which the data may be retrieved for transmission.

[0068] The HARQ scheme can be used for packet transmission in the physical layer. More specifically, if a NACK is received in response to a packet transmission, the HARQ scheme can provide faster packet retransmission than a secondary retransmission. Repeated retransmission of the same packet can be referred to as chase combining. When different bit patterns are sent for decoding the previous symbol, the process can be referred to as incremental redundancy. For incremental redundancy, PDSCH symbols may not be discarded based on unsuccessful decoding. PDSCH symbols of the same HARQ bit may be retained for superimposing PDSCH symbols via FEC to recover the symbols. The circular buffer 512 can therefore provide increased performance with low implementation complexity.

[0069] Bit selection 514 can be used to extract consecutive bits from the circular buffer 512 to match the number of bits corresponding to the transmitted resource block (RB). For example, when a PDSCH is scheduled, a certain number of RBs, bits and / or modulation characteristics can be assigned to the PDSCH. The number of bits that can be included in the corresponding resource allocation can then be selected and sent from the circular buffer 512. The exact set of bits to be extracted for transmission can depend on the RV, which can further depend on different starting positions from the circular buffer 512. For example, the bits selected from the circular buffer 512 can depend on the RV sent at that point in time (e.g., RV 0 and RV 1 can start and end at different positions associated with the circular buffer 512, respectively).

[0070] In certain aspects, the transmission of a TB may be based on four different RVs, which may correspond to RV 0, RV 1, RV 2, and RV 3. During transmission, the RV may be selected by a scheduler and provided to a receiver based on signaling or a predefined sequence. The transmitted RV may be configurable and / or dynamic. For example, a UE may execute a command for transmission in the UL, but in the DL, the base station may overrule the command even if the base station performs similar techniques as the UE. An example RV model may be associated with a sequence RV 0, RV 2, RV 3, RV 1 (e.g., in that order). After RV 1 is transmitted, there may be no further RVs for the TB, so that the transmission of the next TB may be performed immediately following RV 1. In these aspects, the sequence of the RV model may be controlled by the network via DCI.

[0071] If RV 0 is received in the DL and the UE does not successfully decode the associated code block / symbol, the UE may indicate a NACK to the network in the UL. If RV 0 is lost / not decoded (e.g., HARQ MAC TB 0 is sent, but RV 0 is not determined), the UE may not be able to decode other RVs that follow RV 0. That is, if RV 0 is not decoded in the DL, for example, due to failed PDCCH decoding (whose scheduling may not be determined) or due to tune-out, block error rate (BLER), connected mode discontinuous reception (CDRX) configuration failure, etc., the UE may not indicate HARQ feedback in the UL, and the network may assume DTX. More specifically, if the UE does not provide an ACK or a NACK, DTX may be assumed by the network. In aspects where the UE decodes the PDCCH but fails to decode the PDSCH, the PDSCH symbols may be retained for recovery techniques. If the UE fails to recover the PDSCH symbols, the UE may send a NACK. For both NACK / DTX cases, the network may retransmit the MAC TB using other redundancy versions (eg, RV 2, RV 3, RV 1) in subsequent DL transmissions to enable HARQ level recovery at the receiver by increasing FEC opportunities.

[0072] If the UE completely misses RV 0 in the DL (e.g., RV 0 is lost), even if other RVs (e.g., RV 2, RV 3, RV 1) are successfully decoded, the UE may not be able to reliably decode the complete MAC TB due to the loss of the systematic bit 502 in RV 0. Therefore, even if RV 0 can be recovered in some cases, the UE may suspend the HARQ retransmission logic when RV 0 is determined to be lost based on the configuration information. For example, after RV 0 is lost, it may not be practical for the UE and the network to continue decoding / scheduling subsequent HARQ retransmissions with respect to the MAC TB. In addition, continuing to perform such a procedure may result in wasted resources caused by subsequent retransmissions, which reduce the overall capacity of the physical layer and / or cause delayed transmission of subsequent data from the MAC in subsequent instances of the HARQ procedure.

[0073] Figure 6 Figures 600-650 associated with RV 0 decoding failure are included. When the UE determines that RV 0 is lost for a given HARQ, the UE can abort the HARQ retransmission request by indicating a HARQ-ACK to the network. Forced HARQ-ACK enables the network to proceed to the next HARQ program for transmission of the next MAC TB. In aspect, if the UE is configured with RLC ARQ mode, the next HARQ program can be executed while recovering the lost information of the previous HARQ through the radio link control (RLC) level automatic repeat request (ARQ). RLC can request packet retransmission at the RLC level, which can reduce latency compared to waiting for MAC recovery. For certain coding rates at the MAC TB level, the UE may be able to successfully recover. The UE can determine where the forced ACK can be provided to the network in the UL based on the coding rate, physical characteristics and / or information indicated via DCI (e.g., MCS, RV instance, etc.).

[0074] A forced HARQ-ACK may be sent when subsequent retransmissions (such as RV 2, RV 3, and RV 1) use a reserved MCS (e.g., when RV 0 is lost and the MCS is indicated by the network via RV 0). That is, an MCS (such as MCS 15) may be indicated to the UE based on the transmission of RV 0 and may not be re-indicated to the UE at the transmission time of RV 2, RV 3, or RV 1. Instead, subsequent RVs may be associated with a reserved MCS that corresponds to the same MCS as that used for RV 0. However, if RV 0 is lost, the MCS may not be determined for decoding RV 2, RV 3, and RV 1. Therefore, even if the UE will successfully receive RV 2, RV 3, and / or RV 1, the UE may not have sufficient information to identify the MCS for retransmission (e.g., as MCS 15 or some other MCS) based on the failed decoding of RV 0. That is, if the network uses the same MCS in subsequent retransmissions, the network may not indicate the MCS for the retransmission to the UE a second time (e.g., the network may utilize a value of 0). In the example of indicating MCS 15 via RV 0, the next retransmission may not indicate that MCS 15 is associated with RV 0. Thus, a decoding error of the initial transmission corresponding to RV 0 may preclude the UE from being able to decode the remaining RVs.

[0075] Even when successful retransmissions of RV 2, RV 3, and RV 1 are associated with the determined MCS, the UE may not be able to decode these retransmissions due to the coding rate. For example, the initial transmission may indicate MCS 15, and the retransmission may indicate a different MCS (e.g., MCS 10 or MCS 8) so that the retransmission includes the determined MCS. In such cases, there may not be enough parity bits to perform decoding because the number of bits corresponding to different MCSs is reduced. Therefore, in some aspects, successful decoding may depend on the coding rate. A low coding rate may provide an increased probability of successful decoding based on an increased number of parity bits, and a high coding rate may provide a reduced probability of successful decoding based on a reduced number of parity bits. When the UE operates at or near the peak operating rate, high coding rates and additional delays may be avoided.

[0076] A lower coding rate may correspond to more redundant bits in the channel coding process, and a higher coding rate may correspond to fewer redundant bits in the channel coding process. In the example based on 16 HARQs, excessive retransmissions may delay the next transmission. For full scheduling, which may assume that each slot is continuously scheduled, the next transmission / next MAC TB may be delayed by 32 slots (e.g., 16 HARQs × 2 wasted / excessive retransmissions). For sparse scheduling, 10% of the scheduling may be allocated to a UE, where the next transmission / next MAC TB may be delayed by 320 slots (e.g., 16 HARQs × 2 wasted / excessive retransmissions spaced by 1 slot every 10 slots).

[0077] Layer 2 logic can be improved based on reducing the time to receive the next MAC TB. Given that the HARQ procedure may end abruptly in some cases, timely indication to the RLC of RLC packet data unit (PDU) loss can reduce the latency of ARQ mechanisms or other fast NACK mechanisms. Some configurations can pause for the previous HARQ to complete before triggering a retransmission. Therefore, the amount of time that memory buffers are maintained at the MAC level can be reduced, which can improve aspects associated with memory management.

[0078] In diagram 600, HARQ RV 0 is lost and a first NACK is sent based on the lost HARQ RV 0. Subsequently, RV 2 is received, unsuccessfully decoded, and a second NACK is sent. The process is repeated for RV 3 and RV 1 until the end of MAC TB 0 is reached and an ACK / NACK is sent to start MAC TB 1. In a configuration, after the initial transmission and three retransmissions, the network may stop the retransmission process and proceed with the next transmission of the next MAC TB (e.g., MAC TB 1). The UE may determine that the next transmission corresponds to the next MAC TB based on a new data indicator (NDI) bit, which may toggle between TB 0 and TB 1. In other configurations, eight retransmissions may be performed before the next MAC TB is sent based on toggling the NDI bit.

[0079] In diagram 600, MAC TB 1 is delayed by 4T, where T is the time interval between transmissions / retransmissions. Even though the UE can determine that RV 0 is lost, a time delay of 4T may still occur before the next TB (e.g., MAC TB 1) is sent. When RV 0 is lost, the network can assume DTX because no ACK / NACK is received from the UE. However, if RV 2 is received by the UE but is not what the UE expected, retransmissions of RV 3 and RV 1 may not need to be performed because the UE may not be able to decode RV 3 and RV 1. Instead, as illustrated in diagram 650, the UE can send a forced ACK to the network so that transmission / reception of the next MAC TB can be performed without any further delays from the remaining retransmissions of MAC TB 0. In diagram 650, the delay between the time RV 0 is lost and the time MAC TB 1 is received can be reduced to 2T. In a further aspect, if one or more other RVs of the HARQ will be received before RV 0 will be received, a forced ACK may not be sent until after a time when RV 0 is expected (eg, after RV 0 is lost).

[0080] Although Figures 600-650 illustrate the delay of 1 HARQ process, in a configuration, there may be 16 HARQ processes executed at the physical layer within the MAC. Therefore, if HARQ 0-15 are executed one after another, there may be a large cumulative time delay (e.g., based on wasted resources / excessive retransmissions). For example, each retransmission can be spaced across 16 time slots. From HARQ 0, MAC TB 0, RV 0 to the last RV of HARQ, there may be 64 time slots before HARQ 1, MAC TB 1, RV 0 is received by the UE. Based on the forced ACK approach of Figure 650, in which, for example, RV 2 can be received but cannot be decoded, the UE can send a forced ACK for transitioning to MAC TB 1 without further delay caused by retransmissions of the remaining RVs of MAC TB 0. In this way, the spacing can be reduced from 64 time slots to 32 time slots.

[0081] In the foregoing example, the reduction from 64 time slots to 32 time slots is based on full scheduling, where the UE can receive resources from the base station in 100% of the available time slots. However, a more realistic peak rate may occur at a scheduling of around 10%, where one-tenth of the total resources from the base station can be allocated to the UE at a given time. For a 10% time division multiplexing (TDM) schedule, 640 time slots may be used before MAC TB 1 is received by the UE (e.g., without a forced ACK). Continuing with the example, a forced ACK can reduce the spacing from 640 time slots to 320 time slots. The duration of 320ms corresponding to the reduction in time slots of 320 is a sufficient time period for 3 retransmissions. When such a reduction in the number of time slots occurs relative to multiple HARQs, multiple physical layer resources may be saved instead of being wasted on retransmissions that cannot be decoded by the UE, thereby reducing latency based on the UE receiving incoming data more quickly.

[0082] Figure 7 Flowchart 700 of a method of wireless communication. The method may be performed by a wireless receiver (e.g., UE 104, wireless receiver 402, base station 102, wireless transmitter 404, device 902, device 1002, etc.). In aspects where the wireless receiver is a UE, the wireless receiver may include a memory 360, which may be the entire wireless receiver or a component of the wireless receiver, such as a TX processor 368, an RX processor 356, and / or a controller / processor 359. In aspects where the wireless receiver is a base station, the wireless receiver may include a memory 376, which may be the entire wireless receiver or a component of the wireless receiver, such as a TX processor 316, an RX processor 370, and / or a controller / processor 375.

[0083] At 702, the wireless receiver may determine that a transmission of a first TB based on a first redundancy version has not been received from the wireless transmitter. Figure 4 and Figure 6 , the first redundancy version may be RV 0. Diagrams 600-650 indicate that RV 0 for HARQ DL MAC TB 0 is not received by the wireless receiver (e.g., based on determining that RV 2 is unexpectedly received from the wireless transmitter, which RV 2 will inherit the reception of RV 0). Diagram 400 similarly illustrates that the wireless receiver 402 determines at 412 that RV 0 is lost based on the unexpected reception of RV 2 from the wireless transmitter 404. The determination at 702 may be performed, for example, by the determining component 940 / 1040 of the apparatus 902 / 1002.

[0084] At 704, the wireless receiver may send a HARQ ACK to the wireless transmitter to terminate one or more HARQ retransmissions associated with one or more different redundancy versions of the first TB. Figure 4 and Figure 6 , a forced ACK indicated via diagram 650 may be sent to the wireless transmitter to terminate RV 3 and RV 1 of MAC TB 0. Diagram 400 similarly illustrates that the wireless receiver 402 may send a forced ACK at 416 to the wireless transmitter 404 to terminate one or more HARQ retransmissions at 418. The determination at 704 may be performed, for example, by the transmitting component 934 / 1034 of the apparatus 902 / 1002.

[0085] Figure 8 800 is a flow chart of a method of wireless communication. The method may be performed by a wireless receiver (e.g., UE 104, wireless receiver 402, base station 102, wireless transmitter 404, device 902, device 1002, etc.). In aspects where the wireless receiver is a UE, the wireless receiver may include a memory 360, which may be the entire wireless receiver or a component of the wireless receiver, such as a TX processor 368, an RX processor 356, and / or a controller / processor 359. In aspects where the wireless receiver is a base station, the wireless receiver may include a memory 376, which may be the entire wireless receiver or a component of the wireless receiver, such as a TX processor 316, an RX processor 370, and / or a controller / processor 375.

[0086] At 802, the wireless receiver may determine that a particular HARQ transmission corresponding to a first redundancy version of a first TB is not received from the wireless transmitter. Figure 4 and Figure 6 , the first redundancy version may be RV 0. Diagrams 600-650 indicate that RV 0 for HARQ DL MAC TB 0 is not received by the wireless receiver (e.g., based on determining that RV 2 is unexpectedly received from the wireless transmitter, which will inherit the reception of RV 0). Diagram 400 similarly illustrates that the wireless receiver 402 determines at 412 that RV 0 is lost based on the unexpected reception of RV 2 from the wireless transmitter 404. The determination at 802 may be performed, for example, by the determining component 940 / 1040 of the apparatus 902 / 1002.

[0087] At 804, the wireless receiver may determine whether to terminate additional HARQ retransmissions associated with different redundancy versions of the same first TB upon determining that the particular HARQ transmission not received corresponds to the first redundancy version. Figures 4 to 6, the wireless receiver may determine whether to terminate RV 3 and RV 1 of the HARQ DL MAC TB 0 included in diagram 600 upon determining that RV 0 is not received (e.g., based on the undesired reception of RV 2). Diagram 400 similarly illustrates that the wireless receiver 402 determines at 414 to terminate retransmissions associated with the remaining RVs of the MAC TB. The wireless receiver 402 may determine to terminate / send ACK to terminate the additional HARQ retransmissions (e.g., RV 3 and RV 1) based on at least one of the following determinations: a certain number of systematic bits (e.g., systematic bits 502) are lost from a particular HARQ transmission (e.g., RV 0), the number being greater than a systematic bit threshold, a coding rate associated with a particular HARQ transmission (e.g., RV 0) being greater than a coding rate threshold, a number of HARQ processes (e.g., HARQ 0-15) being greater than a HARQ process threshold, or a scheduling delay being greater than a scheduling delay threshold. In a further aspect, when the additional HARQ retransmissions (e.g., RV 3 and RV 1) indicate a reserved MCS for a lost HARQ transmission (e.g., RV 0) in which the MCS is indicated, the wireless receiver may determine to terminate / send an ACK to terminate the additional HARQ retransmissions (e.g., RV 3 and RV 1). The determination at 804 may be performed, for example, by the determining component 940 / 1040 of the apparatus 902 / 1002.

[0088] At 806, the wireless receiver may receive additional HARQ retransmissions associated with different redundancy versions (e.g., RV 3 and RV 1) of the same first TB (e.g., MAC TB 0) when determining not to terminate the additional HARQ retransmissions / retain the additional HARQ retransmissions associated with different redundancy versions (e.g., RV 3 and RV 1) of the same first TB (e.g., MAC TB 0) based on the particular HARQ transmission that was not received corresponding to the first redundancy version (e.g., RV 0). The receiving at 806 may be performed by, for example, the HARQ retransmission component 942 / 1042 via the receiving component 930 / 1030 of the apparatus 902 / 1002.

[0089] At 808, the wireless receiver may send a HARQ ACK to the wireless transmitter to terminate the additional HARQ retransmissions associated with the different redundancy versions of the first TB upon determining to terminate the additional HARQ retransmissions. Figure 4 and Figure 6, a forced ACK indicated via diagram 650 may be sent to the wireless transmitter to terminate RV 3 and RV 1 of MAC TB 0. Diagram 400 similarly illustrates that the wireless receiver 402 may send a forced ACK at 416 to the wireless transmitter 404 to terminate one or more HARQ retransmissions at 418. In a first configuration, the wireless receiver 402 may be a UE and the wireless transmitter 404 may be a base station. In a second configuration, the wireless receiver 402 may be a base station and the wireless transmitter 404 may be a UE. The sending at 808 may be performed by, for example, the ACK / NACK component 944 / 1044 via the sending component 934 / 1034 of the apparatus 902 / 1002.

[0090] At 810, the wireless receiver may receive at least one HARQ transmission associated with the second TB from the wireless transmitter. Figure 4 and Figure 6 , a second TB (e.g., MAC TB 1) associated with a second HARQ transmission (HARQ 1) may be received from the wireless transmitter. Diagram 400 similarly illustrates that the wireless receiver 402 may receive RV 0 of the next MAC TB at 420. The reception at 810 may be performed, for example, by the receiving component 930 / 1030 of the apparatus 902 / 1002.

[0091] Fig. 9900 is a diagram illustrating an example of a hardware implementation for an apparatus 902. The apparatus 902 may be a UE, a component of a UE, or may implement UE functionality. In some aspects, the apparatus 902 may include a cellular baseband processor 904 (also referred to as a modem) coupled to a cellular RF transceiver 922. In some aspects, the apparatus 902 may also include one or more subscriber identity modules (SIM) cards 920, an application processor 906 coupled to a secure digital (SD) card 908 and a screen 910, a Bluetooth module 912, a wireless local area network (WLAN) module 914, a global positioning system (GPS) module 916, or a power supply 918. The cellular baseband processor 904 communicates with the UE 104 and / or the BS 102 / 180 via the cellular RF transceiver 922. The cellular baseband processor 904 may include a computer-readable medium / memory. The computer-readable medium / memory may be non-temporary. The cellular baseband processor 904 is responsible for general processing, including executing software stored on the computer-readable medium / memory. The software, when executed by the cellular baseband processor 904, causes the cellular baseband processor 904 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 904 when executing the software. The cellular baseband processor 904 also includes a receiving component 930, a communication manager 932, and a transmitting component 934. The communication manager 932 includes one or more of the components illustrated. The components within the communication manager 932 may be stored in a computer-readable medium / memory and / or configured as hardware within the cellular baseband processor 904. The cellular baseband processor 904 may be a component of the UE 350 and may include a memory 360 and / or at least one of a TX processor 368, an RX processor 356, and a controller / processor 359. In one configuration, the device 902 may be a modem chip and include only the baseband processor 904, and in another configuration, the device 902 may be the entire UE (e.g., see Figure 3 350) and includes additional modules of device 902.

[0092] The HARQ retransmission component 942 is configured to receive, via the receiving component 930, additional HARQ retransmissions associated with different redundancy versions of the same first TB, e.g., as combined with Figure 8806 in . For example, as described in combination with 810, the receiving component 930 is configured to receive at least one HARQ transmission associated with the second TB from the wireless transmitter. The ACK / NACK component 944 is configured to: send a HARQ ACK to the wireless transmitter via the sending component 934 to terminate one or more HARQ retransmissions associated with one or more different redundancy versions of the first TB; and send a HARQ ACK to the wireless transmitter to terminate additional HARQ retransmissions associated with different redundancy versions of the first TB when determining to terminate additional HARQ retransmissions, for example, as described in combination with 704 and / or 808.

[0093] The communication manager 932 includes a determination component 940, for example, as described in combination with 702, 802 and 804, the determination component 940 is configured to: determine that a transmission of a first TB based on a first redundant version is not received from the wireless transmitter; determine that a specific HARQ transmission corresponding to the first redundant version of the first TB is not received from the wireless transmitter; and when it is determined that the specific HARQ transmission that is not received corresponds to the first redundant version, determine whether to terminate additional HARQ retransmissions associated with different redundant versions of the same first TB.

[0094] The device may include additional components that perform Figures 7 and 8 Each of the algorithm boxes in the flowchart. Thus, Figures 7 and 8 Each block in the flowchart of can be performed by a component, and the apparatus may include one or more of these components. These components can be one or more hardware components that are specifically configured to implement the stated process / algorithm, implemented by a processor configured to execute the stated process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0095] As shown, the apparatus 902 may include a variety of components configured for various functions. In one configuration, the apparatus 902, and in particular the cellular baseband processor 904, includes: a component for determining that a transmission of a first TB based on a first redundancy version has not been received from a wireless transmitter; and a component for sending a HARQ ACK to the wireless transmitter to terminate one or more HARQ retransmissions associated with one or more different redundancy versions of the first TB. The apparatus 902 may also include a component for receiving at least one HARQ transmission associated with a second TB from the wireless transmitter.

[0096] The means may be one or more of the components of the apparatus 902 configured to perform the functions recited by the means. As described above, the apparatus 902 may include the TX processor 368, the RX processor 356, and the controller / processor 359. Thus, in one configuration, the means may be the TX processor 368, the RX processor 356, and the controller / processor 359 configured to perform the functions recited by the means.

[0097] Fig.10 1000 is a diagram illustrating an example of a hardware implementation for an apparatus 1002. The apparatus 1002 may be a base station, a component of a base station, or may implement base station functionality. In some aspects, the apparatus 902 may include a baseband unit 1004. The baseband unit 1004 may communicate with the UE 104 via a cellular RF transceiver 1022. The baseband unit 1004 may include a computer-readable medium / memory. The baseband unit 1004 is responsible for general processing, including executing software stored on a computer-readable medium / memory. The software, when executed by the baseband unit 1004, causes the baseband unit 1004 to perform the various functions described above. The computer-readable medium / memory may also be used to store data manipulated by the baseband unit 1004 when executing the software. The baseband unit 1004 also includes a receiving component 1030, a communication manager 1032, and a sending component 1034. The communication manager 1032 includes one or more of the components illustrated. The components within the communication manager 1032 may be stored in a computer-readable medium / memory and / or configured as hardware within the baseband unit 1004. The baseband unit 1004 may be a component of the base station 310 and may include a memory 376 and / or at least one of the TX processor 316, the RX processor 370, and the controller / processor 375.

[0098] The HARQ retransmission component 1042 is configured to receive, via the receiving component 1030, additional HARQ retransmissions associated with different redundancy versions of the same first TB, e.g., as combined with Figure 8 806 in . For example, as described in combination with 810, the receiving component 930 is configured to receive at least one HARQ transmission associated with the second TB from the wireless transmitter. The ACK / NACK component 1044 is configured to: send a HARQ ACK to the wireless transmitter via the sending component 1034 to terminate one or more HARQ retransmissions associated with one or more different redundancy versions of the first TB; and send a HARQ ACK to the wireless transmitter to terminate additional HARQ retransmissions associated with different redundancy versions of the first TB when determining to terminate additional HARQ retransmissions, for example, as described in combination with 704 and / or 808.

[0099] The communication manager 1032 includes a determination component 1040, for example, as described in combination with 702, 802 and 804, the determination component 1040 is configured to: determine that a transmission of a first TB based on a first redundant version is not received from the wireless transmitter; determine that a specific HARQ transmission corresponding to the first redundant version of the first TB is not received from the wireless transmitter; and when it is determined that the specific HARQ transmission that is not received corresponds to the first redundant version, determine whether to terminate additional HARQ retransmissions associated with different redundant versions of the same first TB.

[0100] The device may include additional components that perform Figures 7 and 8 Each of the algorithm boxes in the flowchart. Thus, Figures 7 and 8 Each block in the flowchart of can be performed by a component, and the apparatus may include one or more of these components. These components can be one or more hardware components that are specifically configured to implement the stated process / algorithm, implemented by a processor configured to execute the stated process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0101] As shown, the apparatus 1002 may include a variety of components configured for various functions. In one configuration, the apparatus 1002, and in particular the baseband unit 1004, includes: a component for determining that a transmission of a first TB based on a first redundancy version has not been received from a wireless transmitter; and a component for sending a HARQ ACK to the wireless transmitter to terminate one or more HARQ retransmissions associated with one or more different redundancy versions of the first TB. The apparatus 1002 may also include a component for receiving at least one HARQ transmission associated with a second TB from the wireless transmitter.

[0102] The means may be one or more of the components of the apparatus 1002 configured to perform the functions recited by the means. As described above, the apparatus 1002 may include the TX processor 316, the RX processor 370, and the controller / processor 375. Thus, in one configuration, the means may be the TX processor 316, the RX processor 370, and the controller / processor 375 configured to perform the functions recited by the means.

[0103] Accordingly, the wireless receiver may be configured to send a HARQ ACK to the wireless transmitter when the HARQ transmission / retransmission is successfully received and decoded by the wireless receiver, and to send a NACK when the HARQ transmission / retransmission is not successfully received and decoded by the wireless receiver. If the wireless transmitter does not receive an ACK or a NACK from the wireless receiver, the wireless transmitter may determine that DTX has occurred and proceed with retransmission of the next redundancy version (e.g., RV 2). Therefore, if the wireless receiver expects to receive RV 0, but RV 0 is lost / not received, the wireless receiver may unexpectedly receive RV 2. The unexpected reception of RV 2 may indicate to the wireless receiver that RV 0 is lost, which may thereby cause the wireless receiver to send a forced ACK to the wireless transmitter. The forced ACK may terminate additional HARQ retransmissions associated with the remaining different redundancy versions of the TB to reduce resource waste that may be caused by the wireless receiver's inability to decode the additional HARQ retransmissions associated with the remaining different redundancy versions of the TB.

[0104] It is understood that the specific order or hierarchy of the blocks in the disclosed process / flowchart is an illustration of an example approach. Based on design preferences, it is understood that the specific order or hierarchy of the blocks in the process / flowchart can be rearranged. In addition, some blocks can be combined or omitted. The attached method claims present the elements of the various blocks in a sample order and are not meant to be limited to the specific order or hierarchy presented.

[0105] The foregoing description is provided so that any person skilled in the art can 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 may be applicable to other aspects. Therefore, the claims are not intended to be limited to the various aspects shown herein, but to conform to the full scope consistent with the language of the claims, wherein, unless explicitly stated so, reference to an element in the singular form is not intended to mean "one and only one", but "one or more". The word "exemplary" used herein means "used as an example, instance or illustration". Any aspect described as "exemplary" herein is not necessarily interpreted as preferred or superior to other aspects. Unless otherwise clearly 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 multiples of A, multiples of B or multiples of 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 or several members of A, B, or C. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure that are known or will later be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, regardless of whether this disclosure is explicitly recited in the claims, nothing disclosed herein is intended to be dedicated to the public. The words "module," "mechanism," "element," "device," and the like may not replace the word "component." Thus, any claim element should not be interpreted as a component plus function unless the element is explicitly recited using the phrase "component for..."

[0106] The following aspects are merely illustrative and may be combined with other aspects or teachings described herein without limitation.

[0107] Aspect 1 is an apparatus for wireless communication at a wireless receiver, the apparatus comprising: at least one processor coupled to a memory and configured to: determine that a transmission of a first TB based on a first redundant version is not received from a wireless transmitter; and send a HARQ ACK to the wireless transmitter to terminate one or more HARQ retransmissions associated with one or more different redundant versions of the first TB.

[0108] Aspect 2 may be combined with aspect 1 and include: when the one or more HARQ retransmissions indicate a reserved MCS for a lost HARQ transmission in which the MCS is indicated, the wireless receiver sends an ACK to terminate the one or more HARQ retransmissions.

[0109] Aspect 3 may be combined with any one of aspects 1 to 2 and include: the wireless receiver sending an ACK to terminate one or more HARQ retransmissions based on determining that a certain number of systematic bits are lost from the HARQ transmission, the number being greater than a threshold.

[0110] Aspect 4 may be combined with any one of aspects 1 to 3 and include: the wireless receiver sending an ACK to terminate one or more HARQ retransmissions based on a coding rate associated with the HARQ transmission being greater than a threshold.

[0111] Aspect 5 may be combined with any one of aspects 1 to 4 and include: the wireless receiver sending an ACK to terminate one or more HARQ retransmissions based on the number of HARQ processes being greater than a threshold.

[0112] Aspect 6 may be combined with any one of aspects 1 to 5 and include: the wireless receiver sending an ACK to terminate one or more HARQ retransmissions based on the scheduling delay being greater than a threshold.

[0113] Aspect 7 may be combined with any one of aspects 1 to 6 and include: the at least one processor is further configured to receive at least one HARQ transmission associated with the second TB from the wireless transmitter.

[0114] Aspect 8 may be combined with any one of Aspects 1 to 7 and include: the first redundancy version is RV0.

[0115] Aspect 9 may be combined with any one of aspects 1 to 8 and include: the wireless receiver is a UE, and the wireless transmitter is a base station.

[0116] Aspect 10 may be combined with any one of aspects 1 to 8 and include: the wireless receiver is a base station, and the wireless transmitter is a UE.

[0117] Aspect 11 is a method for wireless communication implementing any one of aspects 1 to 10.

[0118] Aspect 12 is an apparatus for wireless communication, the apparatus comprising: means for implementing any one of aspects 1 to 10.

[0119] Aspect 13 is a computer-readable medium storing computer-executable code, which, when executed by at least one processor, causes the at least one processor to implement any one of aspects 1 to 10.

Claims

1. A method for wireless communication at a wireless receiver, comprising: determining that no transmission of a first transport block TB based on a first redundancy version is received from the wireless transmitter; as well as A hybrid automatic repeat request (HARQ) acknowledgement (ACK) is sent to the wireless transmitter based on determining that no transmission of the first TB based on the first redundancy version is received from the wireless transmitter to terminate one or more HARQ retransmissions associated with one or more different redundancy versions of the first TB.

2. The method according to claim 1, wherein: The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions when the one or more HARQ retransmissions indicate a reserved MCS for a lost HARQ transmission in which a modulation and coding scheme MCS is indicated.

3. The method according to claim 1, wherein: The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions based on determining that a number of systematic bits are missing from the HARQ transmission, the number being greater than a threshold.

4. The method according to claim 1, wherein: The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions based on a coding rate associated with the HARQ transmission being greater than a threshold.

5. The method according to claim 1, wherein: The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions based on the number of HARQ processes being greater than a threshold.

6. The method according to claim 1, wherein: The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions based on the scheduling delay being greater than a threshold.

7. The method according to claim 1, further comprising: At least one HARQ transmission associated with a second TB is received from the wireless transmitter.

8. The method according to claim 1, wherein: The first redundancy version is redundancy version zero RV 0.

9. The method according to claim 1, wherein: The wireless receiver is a user equipment UE and the wireless transmitter is a base station BS.

10. The method according to claim 1, wherein: The wireless receiver is a base station BS and the wireless transmitter is a user equipment UE.

11. An apparatus for wireless communication at a wireless receiver, comprising: Memory; as well as at least one processor coupled to the memory and configured to: determining that no transmission of a first transport block TB based on a first redundancy version is received from a wireless transmitter; and A hybrid automatic repeat request (HARQ) acknowledgement (ACK) is sent to the wireless transmitter based on determining that no transmission of the first TB based on the first redundancy version is received from the wireless transmitter to terminate one or more HARQ retransmissions associated with one or more different redundancy versions of the first TB.

12. The device according to claim 11, wherein The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions when the one or more HARQ retransmissions indicate a reserved MCS for a lost HARQ transmission in which a modulation and coding scheme MCS is indicated.

13. The device according to claim 11, wherein: The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions based on determining that a number of systematic bits are missing from the HARQ transmission, the number being greater than a threshold.

14. The device according to claim 11, wherein: The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions based on a coding rate associated with the HARQ transmission being greater than a threshold.

15. The device according to claim 11, wherein The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions based on the number of HARQ processes being greater than a threshold.

16. The device according to claim 11, wherein The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions based on the scheduling delay being greater than a threshold.

17. The device according to claim 11, wherein: The at least one processor is further configured to receive at least one HARQ transmission associated with a second TB from the wireless transmitter.

18. The device according to claim 11, wherein The first redundancy version is redundancy version zero RV 0.

19. The device according to claim 11, wherein: The wireless receiver is a user equipment UE and the wireless transmitter is a base station BS.

20. The device according to claim 11, wherein The wireless receiver is a base station BS and the wireless transmitter is a user equipment UE.

21. An apparatus for wireless communication at a wireless receiver, comprising: means for determining that a transmission of a first transport block TB based on a first redundancy version has not been received from a wireless transmitter; as well as Means for sending a hybrid automatic repeat request (HARQ) acknowledgment (ACK) to a wireless transmitter to terminate one or more HARQ retransmissions associated with one or more different redundancy versions of the first TB based on a determination that no transmission of the first TB based on a first redundancy version was received from the wireless transmitter.

22. The device according to claim 21, wherein The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions when the one or more HARQ retransmissions indicate a reserved MCS for a lost HARQ transmission in which a modulation and coding scheme MCS is indicated.

23. The device according to claim 21, wherein The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions based on determining that a number of systematic bits are missing from the HARQ transmission, the number being greater than a threshold.

24. The device according to claim 21, wherein The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions based on a coding rate associated with the HARQ transmission being greater than a threshold.

25. The device according to claim 21, wherein The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions based on the number of HARQ processes being greater than a threshold.

26. The device according to claim 21, wherein The wireless receiver sends the ACK to terminate the one or more HARQ retransmissions based on the scheduling delay being greater than a threshold.

27. The apparatus of claim 21, further comprising: Means for receiving at least one HARQ transmission associated with a second TB from the wireless transmitter.

28. The device according to claim 21, wherein The first redundancy version is redundancy version zero RV 0.

29. A computer readable medium storing computer executable code which, when executed by at least one processor, causes the at least one processor to: determining that no transmission of a first transport block TB based on a first redundancy version is received from a wireless transmitter; and A hybrid automatic repeat request (HARQ) acknowledgement (ACK) is sent to the wireless transmitter based on determining that no transmission of the first TB based on the first redundancy version is received from the wireless transmitter to terminate one or more HARQ retransmissions associated with one or more different redundancy versions of the first TB.

30. The computer-readable medium of claim 29, wherein: The code, when executed by at least one processor, causes the at least one processor to send the ACK to terminate the one or more HARQ retransmissions when the one or more HARQ retransmissions indicate a reserved MCS for a lost HARQ transmission in which a modulation and coding scheme MCS is indicated.

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