Method and apparatus for triggering feedback retransmission in unlicensed spectrum

Abstract

Methods and apparatus for triggering feedback retransmission in unlicensed spectrum are disclosed. A wireless communication system and method related to providing feedback for DL data are provided. A first wireless communication device communicates a first communication signal with a second wireless communication device. The first wireless communication device communicates a grant with the second wireless communication device for retransmission of feedback associated with the first communication signal. The first wireless communication device communicates the feedback with the second wireless communication device based on the grant.

Description

[0001] Z. Fan, Luo Tao, Zhang Xiaoxia, A. Chandamaracana,

[0002] J. Sun, M. P. John Wilson, Zhou Yan, W. Nan

[0003] This application is a divisional application of the Chinese invention patent application with the application date of January 9, 2020, application number 202080008365.2 (international application number PCT / US2020 / 012933), and invention name “Method and device for triggering feedback retransmission in unlicensed spectrum”.

[0004] Cross-reference to related applications and priority claim

[0005] This application claims priority to and the benefit of U.S. non-provisional patent application No. 16 / 737,258, filed on January 8, 2020, which claims priority to and the benefit of U.S. provisional patent application No. 62 / 792,718, filed on January 15, 2019, both of which are incorporated herein by reference in their entirety. Technical Field

[0006] The present application relates to wireless communication systems, and more particularly, to communicating grants for retransmission feedback based on missed transmission opportunities (TXOPs). Background Art

[0007] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, and the like. These systems may be capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power). A wireless multiple-access communication system may include several base stations (BSs), each of which simultaneously supports communication for multiple communication devices, which may also be referred to as user equipment (UE).

[0008] In order to meet the growing demand for extended mobile broadband connectivity, wireless communication technology is evolving from LTE technology to next-generation New Radio (NR) technology. For example, NR is designed to provide lower latency, higher bandwidth or throughput, and higher reliability compared to LTE. NR is designed to operate over a wide range of frequency bands, for example, from low-frequency bands below about 1 gigahertz (GHz) and mid-frequency bands from about 1 GHz to about 6 GHz, to high-frequency bands, such as millimeter wave (mmWave) bands. NR is also designed to operate across different spectrum types from licensed spectrum to unlicensed and shared spectrum. Spectrum sharing enables operators to opportunistically aggregate spectrum to dynamically support high-bandwidth services. Spectrum sharing can extend the benefits of NR technology to operating entities that may not have access to licensed spectrum.

[0009] One approach to avoiding collisions when communicating in a shared or unlicensed spectrum is to use a listen-before-talk (LBT) procedure to ensure that the shared channel is clear before transmitting signals in the shared channel. For example, a transmitting node may listen to the channel to determine if there is an active transmission in the channel. When the channel is clear, the transmitting node may transmit a preamble to reserve a transmission opportunity (TXOP) in the shared channel and may communicate with the receiving node during the TXOP. Summary of the Invention

[0010] The following summarizes some aspects of the present disclosure to provide a basic understanding of the technology discussed. This summary is not an exhaustive overview of all contemplated features of the present disclosure, and is neither intended to identify key or critical elements of all aspects of the present disclosure nor to delineate the scope of any or all aspects of the present disclosure. Its sole purpose is to present some concepts of one or more aspects of the present disclosure in summary form as a prelude to the more detailed description that will be presented later.

[0011] For example, in one aspect of the present disclosure, a wireless communication method includes: communicating a first communication signal by a first wireless communication device and a second wireless communication device; communicating a grant for retransmitting feedback associated with the first communication signal by the first wireless communication device and the second wireless communication device; and communicating the feedback by the first wireless communication device to the second wireless communication device based on the grant.

[0012] In an additional aspect of the present disclosure, an apparatus includes a transceiver configured to: communicate a first communication signal with a second wireless communication device; communicate a grant to retransmit feedback associated with the first communication signal with the second wireless communication device; and communicate the feedback with the second wireless communication device based on the grant.

[0013] In an additional aspect of the present disclosure, with respect to a computer-readable medium having program code recorded thereon, the program code includes: code for causing a first wireless communication device to communicate a first communication signal with a second wireless communication device; code for causing the first wireless communication device to communicate a grant for retransmitting feedback associated with the first communication signal with the second wireless communication device; and code for causing the first wireless communication device to communicate the feedback with the second wireless communication device based on the grant.

[0014] In an additional aspect of the present disclosure, an apparatus includes: means for communicating a first communication signal with a second wireless communication device; means for communicating a grant to retransmit feedback associated with the first communication signal with the second wireless communication device; and means for communicating the feedback with the second wireless communication device based on the grant.

[0015] After studying the following description of specific example embodiments of the present disclosure in conjunction with the accompanying drawings, other aspects, features, and embodiments of the present disclosure will be apparent to those of ordinary skill in the art. Although features of the present disclosure may be discussed below with respect to certain embodiments and drawings, all embodiments of the present disclosure may include one or more of the advantageous features discussed herein. In other words, although one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used according to the various embodiments of the present disclosure discussed herein. In a similar manner, although example embodiments may be discussed below as device, system, or method embodiments, it should be appreciated that such example embodiments may be implemented in various devices, systems, and methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A wireless communication network is illustrated in accordance with some embodiments of the present disclosure.

[0017] Figure 2 A communication scheme for conveying a grant for retransmission feedback is illustrated in accordance with some embodiments of the present disclosure.

[0018] Figure 3 A communication scheme for conveying a grant for retransmission feedback is illustrated in accordance with some embodiments of the present disclosure.

[0019] Figure 4 A communication scheme for conveying a grant for retransmission feedback is illustrated in accordance with some embodiments of the present disclosure.

[0020] Figure 5 is a block diagram of an example user equipment (UE) according to various embodiments of the present disclosure.

[0021] Figure 6 is a block diagram of an example base station (BS) according to various embodiments of the present disclosure.

[0022] Figure 7 is a flow chart of a method of communicating a grant for retransmission feedback according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0023] 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 configurations in which the concepts described herein may be practiced. This detailed description includes specific details to provide a thorough understanding of the various concepts. 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 to avoid obscuring such concepts.

[0024] The present disclosure generally relates to wireless communication systems (also referred to as wireless communication networks). In various embodiments, various techniques and devices can be used for wireless communication networks, such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, fifth generation (5G) or new radio (NR) networks, and other communication networks. As described herein, the terms "network" and "system" can be used interchangeably.

[0025] OFDMA networks can implement radio technologies such as Evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE802.20, flash-OFDM, etc. UTRA, E-UTRA, and Global System for Mobile Communications (GSM) are parts of the Universal Mobile Telecommunications System (UMTS). Specifically, Long Term Evolution (LTE) is a version of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS, and LTE are described in documents provided by an organization called the "3rd Generation Partnership Project" (3GPP), while cdma2000 is described in documents from an organization called the "3rd Generation Partnership Project 2" (3GPP2). These various radio technologies and standards are either known or under development. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between a group of telecommunications associations that aims to define globally applicable third generation (3G) mobile phone specifications. 3GPP Long Term Evolution (LTE) is a 3GPP project aimed at improving the Universal Mobile Telecommunications System (UMTS) mobile phone standard. 3GPP may define specifications for next generation mobile networks, mobile systems, and mobile devices. This disclosure focuses on the evolution of wireless technologies from LTE, 4G, 5G, NR, and beyond, with shared access to wireless spectrum between networks using a collection of new and different radio access technologies or radio air interfaces.

[0026] Specifically, 5G networks envision diverse deployments, diverse spectrum, and diverse services and devices that can be implemented using a unified air interface based on OFDM. To achieve these goals, in addition to developing new radio technologies for 5G NR networks, further enhancements to LTE and LTE-A are also being considered. 5G NR will be able to scale to provide coverage for: (1) networks with ultra-high density (e.g., approximately 1M nodes / km) 2(1) Massive Internet of Things (IoT) with ultra-low complexity (e.g., about tens of bits / second), ultra-low energy (e.g., about 10+ years of battery life), and deep coverage to reach challenging locations; (2) mission-critical control including strong security (to protect sensitive personal, financial, or confidential information), ultra-high reliability (e.g., about 99.9999% reliability), ultra-low latency (e.g., about 1 ms), and users with a wide range of mobility or lack of mobility; and (3) enhanced mobile broadband including very high capacity (e.g., about 10 Tbps / km 2 ), extreme data rates (e.g., multi-Gbps rates, 100+Mbps user experience rates), and deep cognition with advanced discovery and optimization.

[0027] 5G NR can be implemented to: use an optimized OFDM-based waveform with scalable parameter sets and transmission time intervals (TTIs); have a common, flexible framework to efficiently multiplex services and features using dynamic, low-latency time division duplex (TDD) / frequency division duplex (FDD) designs; and have advanced wireless technologies such as massive multiple-input multiple-output (MIMO), robust millimeter wave (mmWave) transmission, advanced channel coding, and device-centric mobility. The scalability of the parameter sets in 5G NR (and the scaling of subcarrier spacing) can efficiently address the operation of diverse services across diverse spectrums and diverse deployments. For example, in various outdoor and macro coverage deployments implemented with less than 3 GHz FDD / TDD, the subcarrier spacing can occur at 15 kHz, such as on 1, 5, 10, 20 MHz, etc. BW. For other various outdoor and small cell coverage deployments with TDD greater than 3 GHz, the subcarrier spacing can occur at 30 kHz on 80 / 100 MHz BW. For various other indoor broadband implementations, using TDD on the unlicensed portion of the 5 GHz band, subcarrier spacing can occur at 60 kHz over 160 MHz BW. Finally, for various deployments transmitting using the mmWave component with TDD at 28 GHz, subcarrier spacing can occur at 120 kHz over 500 MHz BW.

[0028] 5G NR's scalable parameter set facilitates scalable TTIs to meet diverse latency and quality of service (QoS) requirements. For example, shorter TTIs can be used for low latency and high reliability, while longer TTIs can be used for higher spectral efficiency. Efficient multiplexing of long and short TTIs allows transmissions to start on symbol boundaries. 5G NR also contemplates a self-contained integrated subframe design with uplink (UL) / downlink (DL) scheduling information, data, and acknowledgments in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, and supports adaptive UL / DL that can be flexibly configured on a per-cell basis to dynamically switch between UL and DL to meet current traffic needs.

[0029] Various other aspects and features of the present disclosure are further described below. It should be apparent that the teachings herein can be embodied in a variety of forms, and any specific structure, function, or both disclosed herein are representative and non-limiting. Based on the teachings herein, it will be appreciated by those of ordinary skill in the art that the aspects disclosed herein can be implemented independently of any other aspects and that two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement a device or practice a method. In addition, other structures, functionality, or structures and functionality that supplement or differ from one or more aspects set forth herein can be used to implement such a device or practice such a method. For example, the method can be implemented as a part of a system, device, apparatus, and / or as instructions stored on a computer-readable medium for execution on a processor or computer. Not only that, an aspect can include at least one element of a claim.

[0030] Figure 1 A wireless communication network 100 according to some embodiments of the present disclosure is illustrated. Network 100 may be a 5G network. Network 100 includes several base stations (BSs) 105 and other network entities. BSs 105 may be stations that communicate with UEs 115 and may also be referred to as evolved Node Bs (eNBs), next-generation eNBs (gNBs), access points, and the like. Each BS 105 may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to the particular geographic coverage area of ​​a BS 105 and / or the BS subsystem serving that coverage area, depending on the context in which the term is used.

[0031] BS105 can provide communication coverage for macro cells or small cells (such as pico cells or femto cells), and / or other types of cells. Macro cells generally cover a relatively large geographic area (e.g., a radius of several kilometers) and can allow unrestricted access by UEs that have service subscriptions with a network provider. Small cells (such as pico cells) generally cover a relatively small geographic area and can allow unrestricted access by UEs that have service subscriptions with a network provider. Small cells (such as femto cells) generally also cover a relatively small geographic area (e.g., a residence) and, in addition to unrestricted access, can also provide restricted access for UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs of users in the residence, etc.). A BS for a macro cell may be referred to as a macro BS. A BS for a small cell may be referred to as a small cell BS, a pico BS, a femto BS, or a home BS. In Figure 1 In the example shown in FIG, BSs 105d and 105e may be conventional macro BSs, while BSs 105a-105c may be macro BSs enabled with one of three-dimensional (3D), full-dimensional (FD), or massive MIMO. BSs 105a-105c may utilize their higher-dimensional MIMO capabilities to utilize 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. BS 105f may be a small cell BS, which may be a home node or a portable access point. BS 105 may support one or more (e.g., two, three, four, etc.) cells.

[0032] Network 100 may support synchronous or asynchronous operation. For synchronous operation, each BS may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, each BS may have different frame timing, and transmissions from different BSs may not be aligned in time.

[0033] UEs 115 are dispersed throughout wireless network 100, and each UE 115 may be stationary or mobile. UE 115 may also be referred to as a terminal, mobile station, subscriber unit, station, etc. UE 115 may be a cellular phone, personal digital assistant (PDA), wireless modem, wireless communication device, handheld device, tablet computer, laptop computer, cordless phone, wireless local loop (WLL) station, etc. In one aspect, UE 115 may be a device that includes a Universal Integrated Circuit Card (UICC). In another aspect, a UE may be a device that does not include a UICC. In some aspects, UE 115 that does not include a UICC may also be referred to as an IoT device or an Internet of Everything (IoE) device. UEs 115a-115d are examples of mobile smartphone-type devices that access network 100. UE 115 may also be a machine specifically configured for connected communications, including machine-type communications (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT), etc. UEs 115e-115k are examples of various machines configured to communicate for accessing network 100. UE 115 may be capable of communicating with any type of BS (whether a macro BS, a small cell, etc.). Figure 1 , a lightning beam (eg, a communication link) indicates wireless transmission between the UE 115 and the serving BS 105, or desired transmission between BSs and backhaul transmission between BSs, where the serving BS 105 is a BS designated to serve the UE 115 on DL and / or UL.

[0034] In operation, BSs 105a-105c may use 3D beamforming and coordinated spatial techniques (such as coordinated multipoint (CoMP) or multi-connectivity) to serve UEs 115a and 115b. Macro BS 105d may perform backhaul communications with BSs 105a-105c and with small cell BS 105f. Macro BS 105d may also transmit multicast services that are subscribed to and received by UEs 115c and 115d. Such multicast services may include mobile TV or streaming video, or may include other services for providing community information (such as weather emergencies or warnings, such as Amber Alerts or Gray Alerts).

[0035] The network 100 may also support mission-critical communications with ultra-reliable and redundant links for mission-critical devices, such as UE 115e, which may be a drone. The redundant communication links with UE 115e may include links from macro BSs 105d and 105e, as well as a link from small cell BS 105f. Other machine-type devices, such as UE 115f (e.g., a thermometer), UE 115g (e.g., a smart meter), and UE 115h (e.g., a wearable device), may communicate directly with a BS (e.g., small cell BS 105f and macro BS 105e) via the network 100, or in a multi-hop configuration by communicating with another user device that relays its information to the network (e.g., UE 115f conveys temperature measurement information to smart meter UE 115g, which is then reported to the network via small cell BS 105f). The network 100 may also provide additional network efficiency through dynamic, low latency TDD / FDD communications, such as in vehicle-to-vehicle (V2V).

[0036] In some implementations, network 100 utilizes OFDM-based waveforms for communication. OFDM-based systems can divide the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, frequency tones, frequency bins, etc. Each subcarrier can be modulated with data. In some examples, the subcarrier spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system BW. The system BW can also be divided into subbands. In other examples, the subcarrier spacing and / or the duration of the TTI can be scalable.

[0037] In one embodiment, BS 105 may assign or schedule transmission resources (e.g., in the form of time-frequency resource blocks (RBs)) for DL ​​and UL transmissions in network 100. DL refers to the transmission direction from BS 105 to UE 115, while UL refers to the transmission direction from UE 115 to BS 105. The communication may take the form of radio frames. A radio frame may be divided into a plurality of subframes, e.g., approximately 10. Each subframe may be divided into time slots, e.g., approximately 2. Each time slot may be further divided into subslots. In FDD mode, simultaneous UL and DL transmissions may occur in different frequency bands. For example, each subframe includes a UL subframe in the UL frequency band and a DL subframe in the DL frequency band. In TDD mode, UL and DL transmissions occur in different time periods using the same frequency band. For example, a subset of subframes in a radio frame (e.g., DL subframes) may be used for DL ​​transmissions, and another subset of subframes in the radio frame (e.g., UL subframes) may be used for UL transmissions.

[0038] DL subframes and UL subframes can be further divided into several regions. For example, each DL or UL subframe may have a predefined region for the transmission of reference signals, control information, and data. A reference signal is a predetermined signal that facilitates communication between BS105 and UE 115. For example, a reference signal may have a specific pilot pattern or structure, wherein the pilot tones may span an operating BW or frequency band, and each pilot tone is positioned at a predefined time and a predefined frequency. For example, BS105 may transmit a cell-specific reference signal (CRS) and / or a channel state information reference signal (CSI-RS) to enable UE 115 to estimate the DL channel. Similarly, UE 115 may transmit a sounding reference signal (SRS) to enable BS105 to estimate the UL channel. Control information may include resource assignments and protocol control. Data may include protocol data and / or operational data. In some embodiments, BS105 and UE 115 may communicate using self-contained subframes. A self-contained subframe may include a portion for DL ​​communication and a portion for UL communication. A self-contained subframe may be DL-centric or UL-centric. A DL-centric subframe may include a duration for DL ​​communication that is longer than a duration for UL communication. A UL-centric subframe may include a duration for UL communication that is longer than a duration for DL ​​communication.

[0039] After establishing the connection, UE 115 and BS 105 may enter a normal operation phase, during which operational data may be exchanged. For example, BS 105 may schedule UE 105 for UL and / or DL ​​communications. BS 105 may transmit UL and / or DL ​​scheduling grants to UE 115 via a physical DL control channel (PDCCH). BS 105 may transmit DL communication signals to UE 115 via a physical DL shared channel (PDSCH) based on the DL scheduling grant. UE 115 may transmit UL communication signals to BS 105 via a physical UL shared channel (PUSCH) and / or a physical UL control channel (PUCCH) based on the UL scheduling grant.

[0040] BS 105 and UE 115 may further communicate based on the DL transmission parameters and feedback transmission parameters corresponding to the TXOP. The DL transmission parameter indicates the time period between a DL grant and a corresponding DL transmission. The feedback transmission parameter indicates the time period between DL data reception and corresponding feedback for the DL data. The feedback signal may correspond to an ACK or NACK transmission. The DL transmission parameter and the feedback transmission parameter may be preconfigured by the network and may be indicated per time slot. In the context of LTE or NR, the DL transmission parameter and the feedback transmission parameter may be indicated in DL control information (DCI) carried in the PDCCH. For example, if BS 105 reserves the TXOP, the DL transmission parameter may indicate a value of zero, and the feedback transmission parameter may indicate a value of four. The DL transmission parameter may be greater than zero, and the feedback transmission parameter may be less than or greater than four.

[0041] In one embodiment, the network 100 may be an NR network deployed on a licensed spectrum. The network 100 may operate on a shared channel (which may include a shared frequency band or an unlicensed frequency band), for example, at higher frequencies in the 3.5 Gigahertz (GHz), sub-6 GHz, or millimeter wave bands. In such an embodiment, wireless communication devices may share resources in a shared communication medium and may employ a listen-before-talk (LBT) procedure to reserve transmission opportunities (TXOPs) in the shared medium for communication. A TXOP may be non-contiguous in time and may refer to an amount of time in which a station may transmit a frame if it wins contention for the wireless medium. Each TXOP may include multiple time slots and one or more medium listening periods.

[0042] A wireless communication device may perform LBT on a shared channel. When LBT results in LBT being passed (the wireless communication device wins contention for the wireless medium), the wireless communication device may access the shared medium to transmit and / or receive data. In one example, the wireless communication device is BS 105. When LBT results in LBT being passed, BS 105 may schedule UE 115 to communicate on the shared channel during the TXOP. In another example, BS 105 may transmit downlink data and / or time domain resource location information regarding feedback transmission for downlink data to UE 115. In the present disclosure, time domain resources may also be referred to as feedback opportunities. UE 115 may then receive downlink data from BS 105 and transmit feedback regarding the downlink data to BS 105. The feedback may be an acknowledgment (ACK) indicating that the UE successfully received the downlink data (e.g., received the downlink data without error) or a negative acknowledgment (NACK) indicating that the UE unsuccessfully received the downlink data (e.g., received the downlink data without error or error correction failure).

[0043] In another example, the wireless communication device is UE 115. When LBT results in LBT pass, UE 115 can receive DL data and / or time domain resource location information about feedback opportunities for DL ​​data from BS 105. UE 115 can use the feedback opportunity to transmit feedback for the DL data to BS 105. The feedback transmission of UE 115 complies with the LBT constraints. Before transmitting the feedback, UE 115 may perform LBT that results in LBT failure (the UE does not win the contention for the wireless medium). Accordingly, the UE may miss the opportunity to transmit the feedback, and the BS will not receive the feedback as expected. Feedback that BS 105 expected but did not receive can be referred to as failure feedback.

[0044] The present disclosure provides techniques for communicating a grant for feedback retransmission. In some examples, BS 105 provides a grant to trigger a retransmission of failed feedback. Providing a retransmission grant for failure feedback to UE 115 by BS 105 may be advantageous because the ability of UE 115 to transmit feedback on an UL transmission depends on whether UE 115 can obtain access to the medium for transmission and / or reception of data. By providing UE 115 with another opportunity to provide failure feedback to BS 105, UE 115 is more likely to be able to retransmit the failure feedback to BS 105. Additionally, instead of transmitting DL data to UE 115 again, BS 105 can save resources and transmit a grant to UE 115 for retransmission of feedback associated with the DL data. Accordingly, spectrum sharing performance can be improved and feedback latency and / or retransmission scheduling latency can be reduced.

[0045] Figure 2 A communication scheme 200 is illustrated for conveying a grant for retransmission feedback according to some embodiments of the present disclosure. The communication scheme 200 may correspond to a communication scheme between the BS 105 and the UE 115 of the network 100. Figure 2 In , the x-axis represents time in some constant units. Figure 2 The structures 201, 221 of TXOPs 202, 222 in a shared channel are shown, respectively. The TXOPs 202, 222 include a plurality of time slots 204, 214, respectively, in time. The number of time slots within a TXOP may vary depending on the embodiment.

[0046] For simplicity of explanation and discussion, Figure 2It is illustrated that the TXOP 202, 222 includes ten time slots 204, 214 indexed from S0 to S9. The BS can communicate with the UE in units of time slots. A time slot may also be referred to as a TTI. Each time slot or TTI carries a media access control (MAC) layer transport block. Each time slot may include a number of symbols in time and a number of frequency tones in frequency. Each time slot may include a DL control part followed by at least one of a subsequent DL data part, a UL data part, and / or a UL control part. In the context of LTE or NR, the DL control part, the DL data part, the UL data part, and the UL control part may be referred to as PDCCH, PDSCH, PUSCH, and PUCCH, respectively.

[0047] A box filled with a pattern indicates the transmission of DCI, DL data, UL data, ACK, and / or NACK in the corresponding time slot. Although the entire time slot is filled with the pattern, transmission may only occur in the corresponding portion of the time slot. Additionally, an "X" in a box indicates a failed transmission (e.g., due to LBT failure). In the present disclosure, a second attempt to transmit feedback may be referred to as a retransmission of feedback.

[0048] BSs contending for a TXOP in a shared channel may perform LBT in the shared channel. If the LBT results in an LBT pass, the BS 105 may transmit a DCI 220 in the time slot 204 indexed as S1 (e.g., in the DL control portion of the time slot 204). The DCI 220 may indicate a DL grant for the UE 115 in the same time slot 204 indexed as S1 (e.g., K0=0). Therefore, the BS 105 transmits a DL data signal 224 to the UE 115 in the time slot 204 indexed as S1 (e.g., in the DL data portion of the time slot 204). The UE may receive the DCI 220 and receive the DL data signal 224 based on the DL grant.

[0049] After receiving the DL data signal 224, the UE 115 may transmit feedback regarding the DL data signal 224 to the BS 105. The BS 105 may provide the UE 115 with a feedback opportunity regarding the DL data signal 224 in the time slot 204 indexed as S5. A feedback opportunity may refer to a resource location (e.g., a time-frequency resource) during which the UE 115 may provide feedback (e.g., ACK / NACK) regarding the DL data signal. The feedback opportunity may be transmitted at different locations within the time domain resources. An Acknowledgement Resource Indicator (ARI) may convey the resource location of the feedback opportunity and may be, for example, a resource block. Accordingly, the BS 105 may configure the feedback opportunity for the UE 115 to transmit feedback regarding the DL data signal 224 via the TXOP structure configuration. The BS 105 may indicate the resources (e.g., time slots) that the UE 115 may use to provide feedback (e.g., in the time slot 204 indexed as S5). The resources may be provided via the TXOP structure configuration and / or control channel information detected by the UE 115. The BS 105 may indicate the time domain resource location information for the feedback opportunity as the time slot 204 indexed as S5. Accordingly, the UE 115 may transmit feedback for the DL data signal 224 using the time slot 204 indexed as S5.

[0050] The feedback may report the reception status of the DL data signal 224 to the BS 105 by transmitting an ACK / NACK signal 228 in the time slot 204 indexed by S5 (e.g., in the UL data portion or the UL control portion of the time slot 204) based on the ARI. The time slot 204 indexed by S5 is the fourth time slot from the time slot 204 indexed by S1. The ACK / NACK signal 228 refers to a feedback signal that carries an ACK or NACK for the DL data signal 224. When the reception of the DL data signal 224 is successful (e.g., the DL data is received without error), the UE 115 may transmit an ACK. Alternatively, when the reception of the DL data signal 224 is unsuccessful (e.g., includes an error or error correction fails), the UE may transmit a NACK.

[0051] The ACK / NACK signal 228 may be associated with a hybrid automatic repeat request (HARQ) process. In the HARQ process, a transmitting node may transmit various coded versions of information data to a receiving node. For example, the transmitting node may transmit a first coded version of the information data to the receiving node. Upon receiving a NACK signal from the receiving node, the transmitting node may transmit a second coded version of the information data to the receiving node. When both the received first coded version and the received second coded version have errors, the receiving node may combine the received first coded version and the received second coded version for error correction.

[0052] The UE may perform LBT in the shared channel prior to a feedback opportunity (e.g., time slot 204 indexed as S5). The ability of the UE 115 to transmit an ACK / NACK signal 228 during the configured feedback opportunity depends on whether the UE is able to obtain access to the medium for transmission and / or reception of data. If the LBT results in an LBT pass, the UE 115 may transmit the ACK / NACK signal 228 in the time slot 204 indexed as S5. Alternatively, if the LBT results in an LBT fail, the UE 115 may be unable to transmit the ACK / NACK signal 228 based on missing the TXOP. Accordingly, the BS 105 does not receive the ACK / NACK signal 228 when expected (e.g., in the time slot 204 indexed as S5). Figure 2 In the illustrated example, the time slot 204 indexed S5 is marked with an “X,” indicating that the UE 115 cannot transmit an ACK / NACK signal 228 to the BS 105 .

[0053] If BS 105 does not receive ACK / NACK signal 228 from UE 115 as expected, then instead of retransmitting DL data signal 224 to UE 115, BS 105 may explicitly trigger a PUCCH report (e.g., retransmit feedback for DL ​​data signal 224). For example, BS 105 may transmit a communication signal to UE 115 indicating a grant to retransmit failed feedback associated with DL data signal 224. In this manner, UE 115 may receive a trigger indicating that failed feedback for DL ​​data signal 224 is to be retransmitted.

[0054] Referring to TXOP 222, parameter 210 may indicate a value of zero (e.g., K0=0), and parameter 212 may indicate a value of three (e.g., K1=3). BS 105 performs LBT before transmitting in the shared channel. If the LBT results in an LBT pass, BS 105 may transmit DCI 240 to UE 115 in slot 214 indexed as S0 (e.g., in the DL control portion of slot 214). DCI 240 may indicate a grant for retransmitting a failed ACK / NACK signal 228 associated with DL data signal 224. UE 115 may receive DCI 240 indicating a grant for retransmitting the failed ACK / NACK signal 228 and, accordingly, transmit an ACK / NACK signal 228 to BS 105 based on the grant. DCI 240 may indicate an ARI that references slot 214 indexed as S3 for transmission of ACK / NACK signal 228. UE 115 may transmit an ACK / NACK signal 228 to BS 105 in time slot 214 indexed as S3 (eg, in the UL data portion or the UL control portion of time slot 214).

[0055] In some examples, the BS 105 may combine the grant for retransmitting the ACK / NACK signal 228 with the DL grant. For example, the DCI 240 may indicate the grant for retransmitting the ACK / NACK signal 228 and may also indicate a DL grant for the UE 115 in the same time slot 214 indexed as S0 (e.g., K0=0). The BS 105 transmits a DL data signal 244 to the UE 115 in the time slot 214 indexed as S0 (e.g., in the DL data portion of the time slot 214) based on the DL grant. The UE may receive the DCI 240 (which indicates the grant for retransmitting the ACK / NACK signal 228 and the DL grant) and the DL data signal 244 based on the same grant indicated in the DCI 240. In this example, UE 115 may transmit an ACK / NACK signal 228 in a time slot 214 indexed as S3 (e.g., in the UL data portion or the UL control portion of time slot 214), and may also transmit an ACK / NACK signal 246 in a time slot 214 indexed as S4 (e.g., K1=3) (e.g., in the UL data portion or the UL control portion of time slot 214). ACK / NACK signal 246 indicates reception of DL data signal 244 by UE 115. DCI 240 may indicate an ARI that references time slot 214 indexed as S4 for transmission of ACK / NACK signal 246. The ARI that references time slot 214 indexed as S3 for transmission of ACK / NACK signal 228 may be the same as or different from the ARI that references time slot 214 indexed as S4 for transmission of ACK / NACK signal 246.

[0056] ACK / NACK signal 228 and ACK / NACK signal 246 are shown as being transmitted in different time slots (e.g., time slots 214 indexed as S3 and S4, respectively). It should be understood that in other examples, ACK / NACK signal 228 and ACK / NACK signal 246 can be transmitted in the same time slot. Additionally, as will be described below with respect to Figure 3 and 4 As further explained, the transmissions of ACK / NACK signal 228 and ACK / NACK signal 246 may have the same spatial relationship information or different spatial relationship information. Furthermore, although the DCI is described as indicating an ARI that references a specific time slot for transmission within a TXOP, it should be understood that the DCI may indicate feedback transmission parameters that indicate a time period between reception of downlink data and corresponding feedback for the downlink data.

[0057] Figure 3Illustrated is a communication scheme 300 for conveying a grant for retransmission feedback according to some embodiments of the present disclosure. The communication scheme 300 may be employed by a UE (such as UE 115) and a BS (such as BS 105) in a network (such as network 100). Figure 3 306. BS 105 may perform LBT 302 to obtain a TXOP 304 for DL ​​transmission to UE 115 in PDSCH 306. The check mark shown in the LBT indicates that the LBT passed, and an "X" shown in the LBT indicates that the LBT failed. The check mark shown in LBT 302 indicates that LBT 302 resulted in an LBT pass. Accordingly, BS 105 transmits a DL transmission to UE 115 via PDSCH 306.

[0058] UE 115 may receive PDSCH 306 from BS 105 and desire to transmit feedback associated with PDSCH 306 to BS 105. BS 105 may configure UE 115 with feedback opportunity 314 in time slot m for transmitting feedback for PDSCH 306. Before transmitting feedback opportunity 314, UE 115 may perform LBT 312. LBT 312 results in LBT failure. Accordingly, UE 115 is unable to transmit PUCCH 316a in time slot m due to missing feedback opportunity 314.

[0059] BS 105 may expect to receive PUCCH 316a in time slot m during feedback opportunity 314. In response to determining that feedback for PDSCH 306 (e.g., PUCCH 316a) has failed, BS 105 may trigger a retransmission of the feedback. BS 105 may perform LBT 322 to obtain TXOP 324 to transmit PDCCH 326 to UE 115. The check flag shown in LBT 322 indicates that LBT 322 resulted in LBT passing. PDCCH 326 may indicate a trigger for retransmission of failed feedback for PDSCH 306 (e.g., failed PUCCH 316a). PDCCH 326 may indicate a grant to retransmit failed feedback, given that a grant for PDSCH 306 has been transmitted to UE 115 (e.g., the BS may have indicated a grant during TXOP 304) and / or UE 115 has attempted to transmit PUCCH 316a. In some examples, the grant indicated by the PDCCH 326 may indicate UL resources for retransmitting the PUCCH 316a (eg, an ACK / NACK for a previous PDSCH 306).

[0060] UE 115 may receive a PDCCH 326 indicating a grant for retransmitting feedback associated with PDSCH 306. UE 115 may perform LBT 332 based on the grant for retransmitting feedback (e.g., PUCCH 316a) indicated in PDCCH 326 to obtain a feedback opportunity 334 to transmit PUCCH 316b. The check flag shown in LBT 332 indicates that LBT 332 resulted in an LBT pass. UE 115 may transmit PUCCH 316b in time slot n during feedback opportunity 334. PUCCH 316b may include the same feedback as PUCCH 316a, and "retransmitting" PUCCH 316a may refer to transmitting PUCCH 316b. Additionally, to further distinguish PUCCH 316a from PUCCH 316b, PUCCH 316a may also be referred to as a failed PUCCH 316a.

[0061] Additionally, PDCCH 326 may indicate a DL grant associated with new PDSCH 328. BS 105 may transmit new PDSCH 328 to UE 115 during TXOP 324 (e.g., in the DL data portion of a timeslot). UE 115 may receive new PDSCH 328 based on the DL grant indicated by PDCCH 326. PDCCH 326 may indicate a new feedback grant for transmitting feedback for PDSCH 328. In some examples, a trigger for failure feedback (e.g., PUCCH 316a) may be combined with a new feedback grant associated with new PDSCH 328.

[0062] After UE 115 receives new PDSCH 328, UE 115 may transmit new PUCCH 336 based on the new feedback grant indicated in PDCCH 326. New PUCCH 336 may be feedback for new PDSCH 328. Accordingly, the transmission of PUCCH 316b and new PUCCH 336 may be triggered by the same grant. Additionally, PUCCH 316b and new PUCCH 336 correspond to different PDSCHs. In one example, PUCCH 316b indicates feedback for PDSCH 306, and new PUCCH 336 indicates feedback for new PDSCH 328. Accordingly, in some examples, the grant indicated by the PDCCH 326 can indicate a first UL resource for retransmitting the PUCCH 316a (e.g., an ACK / NACK for the previous PDSCH 306), a DL resource for new DL data (e.g., a new PDSCH 328), and a second UL resource for a new PUCCH transmission (e.g., a new PUCCH 336).

[0063] Although UE 115 may transmit PUCCH 316b and new PUCCH 336 (e.g., Figure 3 As shown), it should also be understood that the BS can configure the UE 115 to operate in different time slots (e.g., n and n+1, as shown in FIG. Figure 2 336 transmissions. The time slots between the PUCCH 316b and new PUCCH 336 transmissions may be spaced according to the ARI. Additionally, the resources for the PUCCH 316b and new PUCCH 336 triggered in the same grant may be configured separately or linked together by the two ARIs. Different bits may be used to indicate the time domain resource location information. In one example, a single ARI field may indicate the time domain resource location for both the PUCCH 316b and new PUCCH 336 transmissions. In another example, two different ARI fields may indicate the time domain resource location for the PUCCH 316b and new PUCCH 336 transmissions.

[0064] Furthermore, although the PUCCH 316a associated with the feedback opportunity 314 and the PUCCH 316b associated with the feedback opportunity 334 are shown as being in the same time slot (eg, time slot n, as shown in FIG. Figure 3 As shown), it should be understood that PUCCH 316a and PUCCH 316b can be transmitted in different time slots (as shown in FIG. Figure 2 For example, UE 115 may have attempted to transmit PUCCH 316a in time slot m during feedback opportunity 314 and may have transmitted PUCCH 316b in time slot n during feedback opportunity 334, where m and n correspond to different time slots in the TXOP as configured by the BS.

[0065] Additionally, in some examples, BS 105 can coordinate with UE 115 to collaboratively schedule, beamform, and / or transmit data in network 100. Significant gains can be achieved through increased use of multi-antenna systems. For example, in millimeter wave access, a large number of antenna elements can be used to take advantage of shorter wavelengths and enable beamforming and beam tracking. When using, for example, millimeter wave frequencies, beamforming can be used to avoid transmission losses. Beamforming combines signals from multiple antenna elements in an antenna array so that the combined signal level increases when the phases of the signals are aligned (constructive interference). The signals from each antenna element are transmitted with slightly different phases (delays) to produce a beam directed toward the receiver. At higher frequencies, propagation and penetration losses are higher. Beamforming techniques can be used to increase the signal level received by a device. The beamformer combines energy across its aperture, resulting in a certain antenna gain in a given direction, while having attenuation in other directions. Each of BS 105 and UE 115 can direct its energy in a specific direction. Different transmission beams may correspond to different beam patterns.

[0066] Additionally, the BS may configure the UE 115 with different spatial parameters (e.g., beam directions) for transmitting PUCCH 316b and PUCCH 336. Thus, the UE 115 may steer its energy in a specific direction during PUCCH transmission according to these spatial parameters. Figure 3In the illustrated example, UE 115 may transmit PUCCH in different beam directions. The terms "transmission beam" and "beam" may be used interchangeably in this disclosure. UE 115 may include an array of antenna elements, and the array of antenna elements may be configured to form a transmission beam 311 in a specific direction. Transmission beams 311a, 311b, ... and 311n have different patterns. UE 115 may have attempted to transmit PUCCH 316a on transmission beam 311a pointing in direction 340 (e.g., shown as pattern-filled). During feedback opportunity 334, UE 115 may transmit PUCCH 316b on transmission beam 311b pointing in direction 342 (e.g., shown as pattern-filled). UE 115 may also transmit a new PUCCH 336 on transmission beam 311b pointing in direction 342. In this example, the PUCCH 316a associated with the feedback opportunity 314 and the PUCCH 316b associated with the feedback opportunity 334 may have different spatial relationship information. In another example, the PUCCH 316a and the PUCCH 316b may have the same spatial relationship information. In this example, the UE 115 may have attempted to transmit the PUCCH 316a on the same transmission beam (e.g., transmission beam 311a) that the UE 115 used to transmit the PUCCH 316b. Additionally, the PUCCH 316b and the new PUCCH 336 triggered in the same grant may have the same or different spatial relationship information relative to each other.

[0067] Figure 4 Illustrated is a communication scheme 400 that communicates a grant for retransmission feedback in accordance with some embodiments of the present disclosure. The communication scheme 400 may be employed by a UE (such as UE 115) and a BS (such as BS 105) in a network (such as network 100). Figure 4 Shown from Figure 3 306. UE 115 fails to transmit PUCCH 316a on transmit beam 311a (e.g., shown as pattern-filled) pointing in direction 340 in time slot m. Additionally, BS 105 transmits PDCCH 326 and new PDSCH 328. UE 115 receives PDCCH 326 and new PDSCH 328 from BS 105. PDCCH 326 may indicate a grant for retransmitting feedback associated with PDSCH 306. PDCCH 326 may also indicate a grant for new PDSCH 328 and feedback for new PDSCH 328.

[0068] exist Figure 4In the illustrated example, UE 115 transmits PUCCH 316b on transmit beam 311b (e.g., shown as patterned) pointing in direction 342 in time slot n during feedback opportunity 334. As discussed, UE 115 attempts to transmit PUCCH 316a in time slot m during feedback opportunity, where m and n correspond to different time slots in the TXOP. Additionally, UE 115 transmits new PUCCH 336 on transmit beam 311a (e.g., shown as patterned) pointing in direction 340 in time slot n+1 during feedback opportunity 334. Accordingly, UE 115 may transmit PUCCH 316b and new PUCCH 336 in different time slots and / or using different beam patterns.

[0069] If the BS 105 determines that the feedback from the UE 115 has failed, the BS 105 may trigger a PUCCH report from the UE 115. The BS 105 may request the UE 115 to include, for example, the payload size of the failure feedback (e.g., PUCCH 316a), the bit mask of the DL grant reported in the failure feedback, and / or the payload of the failure feedback. In one example, the grant may request the UE 115 to provide the payload size of the failure feedback, the bit mask of the DL grant reported in the failure feedback, and / or the payload of the failure feedback, among other information.

[0070] The payload size of the failure feedback associated with the communication signal corresponds to the number of ACK / NACKs for the communication signal, and the payload of the failure feedback can refer to the ACK / NACK for the communication signal. In some examples, the failed PUCCH 316a may include feedback for one or more PDSCHs. If BS105 does not receive PUCCH 316a, there may be ambiguity about the payload size between BS105 and UE 115 so that BS105 does not correctly decode PUCCH 316a. Accordingly, in the triggered retransmission, BS105 can request UE 115 to send the payload size of the failed PUCCH 316a. The bit mask can indicate which DL grants UE 115 has received within the time window. The bit mask can be used to indicate which grants (e.g., PDSCH) UE 115 has received for the same original PUCCH feedback. According to the bit mask, BS105 can determine the payload size of the previously received PUCCH.

[0071] Figure 55 is a block diagram of an example UE 500 according to various embodiments of the present disclosure. UE 500 may be UE 115 as discussed above. As shown, UE 500 may include a processor 502, a memory 504, a signal module 505, a grant module 507, a feedback module 509, a transceiver 510 (including a modem subsystem 512 and a radio frequency (RF) unit 514), and one or more antennas 516. These elements may communicate with each other directly or indirectly, for example, via one or more buses.

[0072] The processor 502 may include a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 502 may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0073] Memory 504 may include cache memory (e.g., cache memory of processor 502), random access memory (RAM), magnetoresistive RAM (MRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory devices, hard drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In one embodiment, memory 504 includes a non-transitory computer-readable medium. Memory 504 may store instructions 506. Instructions 506 may include instructions that, when executed by processor 502, cause processor 502 to perform the operations described herein with reference to UE 115 in conjunction with various embodiments of the present disclosure. Instructions 506 may also be referred to as code. The terms "instructions" and "code" should be interpreted broadly to include any type of computer-readable statements. For example, the terms "instructions" and "code" may refer to one or more programs, routines, subroutines, functions, procedures, etc. "Instructions" and "code" may include a single computer-readable statement or a plurality of computer-readable statements.

[0074] Each of the signal module 505, the grant module 507, and the feedback module 509 can be implemented via hardware, software, or a combination thereof. For example, each of the signal module 505, the grant module 507, and the feedback module 509 can be implemented as a processor, a circuit, and / or instructions 506 stored in the memory 504 and executed by the processor 502. Each of the signal module 505, the grant module 507, and the feedback module 509 can be used in various aspects of the present disclosure.

[0075] The signal module 505 may be configured to communicate a first communication signal with the wireless communication device. The first communication signal may be a PDSCH carrying DL data associated with a DL grant. In an example, the signal module 505 receives the first communication signal from the BS 105. Figure 2 , the DL data signal 224 received via the PDSCH may correspond to a first communication signal.

[0076] The grant module 507 can be configured to communicate a grant to retransmit feedback associated with the first communication signal to the wireless communication device. In one example, the grant module 507 receives a DCI indicating a grant to retransmit the feedback. The grant module 507 may have received a previous grant to transmit feedback associated with the first communication signal. Due to a missed feedback opportunity, the feedback module 509 may have been unable to transmit the feedback based on the previous grant.

[0077] Reference Figure 2 , the DCI 240 may indicate a grant for retransmitting the ACK / NACK signal 228, which indicates feedback for the DL data signal 224. The DCI 240 may also indicate a DL grant for the DL data signal 244 in the time slot 214 indexed as S0 and a new feedback grant for the DL data signal 244 in the time slot 214 indexed as S4. Accordingly, the grant for triggering the retransmission of the ACK / NACK signal 228 may be combined with the new feedback grant associated with the DL data signal 244.

[0078] The feedback module 509 can be configured to communicate feedback to the wireless communication device based on the grant. In one example, the feedback module 508 can perform LBT, and if the LBT results in an LBT pass, the feedback module 508 can transmit feedback to the BS 105 based on the grant. Figure 2 , the ACK / NACK signal 228 in the time slot 214 indexed as S3 may correspond to feedback based on the grant indicated in the DCI 240. The feedback may be an ACK indicating that the UE 115 successfully received the DL data or a NACK indicating that the UE 115 did not successfully receive the DL data.

[0079] As shown, transceiver 510 may include a modem subsystem 512 and an RF unit 514. Transceiver 510 may be configured to communicate bidirectionally with other devices, such as BS 105 and / or another core network element. Modem subsystem 512 may be configured to modulate and / or encode data from memory 504, signal module 505, grant module 507, and / or feedback module 509 according to a modulation and coding scheme (MCS) (e.g., a low-density parity-check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc.). RF unit 514 may be configured to process (e.g., perform analog-to-digital conversion or digital-to-analog conversion, etc.) the modulated / encoded data from modem subsystem 512 (on outbound transmissions) or from another source, such as a UE or BS 105. RF unit 514 may further be configured to perform analog beamforming in conjunction with digital beamforming. Although shown as integrated together in the transceiver 510, the modem subsystem 512 and the RF unit 514 may be separate devices that are coupled together at the UE 500 to enable the UE 500 to communicate with other devices.

[0080] The RF unit 514 may provide modulated and / or processed data, such as a data packet (or more generally, a data message that may include one or more data packets and other information), to the antenna 516 for transmission to one or more other devices. The antenna 516 may further receive data messages transmitted from other devices. The antenna 516 may provide the received data messages for processing and / or demodulation at the transceiver 510. The antenna 516 may include multiple antennas of similar or different designs to maintain multiple transmission links. The RF unit 514 may configure the antenna 516.

[0081] Figure 6 6 is a block diagram of an example BS 600 according to various embodiments of the present disclosure. BS 600 may be BS 105 as discussed above. As shown, BS 600 may include a processor 602, a memory 604, a signal module 605, a grant module 607, a feedback module 609, a transceiver 610 (including a modem subsystem 612 and an RF unit 614), and one or more antennas 616. These elements may communicate with each other directly or indirectly, for example, via one or more buses.

[0082] The processor 602 may have various features as a special-purpose type of processor. For example, these features may include a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 602 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0083] Memory 604 may include cache memory (e.g., cache memory of processor 602), RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, solid-state memory devices, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some embodiments, memory 604 may include non-transitory computer-readable media. Memory 604 may store instructions 606. Instructions 606 may include instructions that, when executed by processor 602, cause processor 602 to perform the operations described herein. Instructions 606 may also be referred to as code, which may be broadly interpreted to include the instructions described above with reference to the instructions 606. Figure 5 Any type of computer-readable statement in question.

[0084] Each of the signal module 605, the grant module 607, and the feedback module 609 can be implemented via hardware, software, or a combination thereof. For example, each of the signal module 605, the grant module 607, and the feedback module 609 can be implemented as a processor, a circuit, and / or instructions 606 stored in the memory 604 and executed by the processor 602. Each of the signal module 605, the grant module 607, and the feedback module 609 can be used in various aspects of the present disclosure.

[0085] The signal module 605 may be configured to communicate a first communication signal with the wireless communication device. The first communication signal may be a PDSCH carrying DL data associated with a DL grant. In one example, the signal module 505 transmits the first communication signal to the UE 115. Figure 2 , the DL data signal 224 transmitted via the PDSCH may correspond to a first communication signal.

[0086] The granting module 607 may be configured to communicate with the wireless communication device a grant for retransmitting feedback associated with the first communication signal. In one example, the granting module 607 transmits a DCI indicating the grant for retransmitting the feedback. Figure 2, DCI 240 may indicate a grant for retransmitting ACK / NACK signal 228, which indicates feedback for DL ​​data signal 224. DCI 240 may also indicate a new feedback grant for a new DL data signal 244 (eg, a PDSCH signal).

[0087] In an example, the grant module 607 can detect a missed feedback opportunity. In response to detecting a missed feedback opportunity, the grant module 607 can transmit a retransmission feedback grant (eg, a grant to retransmit feedback associated with the first communication signal).

[0088] The feedback module 609 may be configured to communicate feedback to the wireless communication device based on the grant. In one example, the feedback module 609 may receive feedback from the UE 115 based on the grant. Figure 2 , the ACK / NACK signal 228 in the time slot 214 indexed as S3 may correspond to feedback based on the grant indicated in the DCI 240. The feedback may be an ACK indicating that the UE 115 successfully received the DL data or a NACK indicating that the UE 115 did not successfully receive the DL data.

[0089] As shown, transceiver 610 may include a modem subsystem 612 and an RF unit 614. Transceiver 610 may be configured to communicate bidirectionally with other devices, such as UE 115 and / or another core network element. Modem subsystem 612 may be configured to modulate and / or encode data according to an MCS (e.g., an LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc.). RF unit 614 may be configured to process (e.g., perform analog-to-digital conversion or digital-to-analog conversion, etc.) the modulated / encoded data from modem subsystem 612 (on outbound transmissions) or from another source, such as UE 115 or another BS. RF unit 614 may further be configured to perform analog beamforming in conjunction with digital beamforming. Although shown as being integrated together in transceiver 610, modem subsystem 612 and / or RF unit 614 may be separate devices that are coupled together at BS 600 to enable BS 600 to communicate with other devices.

[0090] The RF unit 614 may provide modulated and / or processed data, such as a data packet (or more generally, a data message that may include one or more data packets and other information), to the antenna 616 for transmission to one or more other devices. This may include, for example, the transmission of information for completing attachment to a network and communication with a resident UE 115 or 500 in accordance with various embodiments of the present disclosure. The antenna 616 may further receive data messages transmitted from other devices and provide the received data messages for processing and / or demodulation at the transceiver 610. The antenna 616 may include multiple antennas of similar or different designs in order to maintain multiple transmission links.

[0091] Figure 7 7 is a flow chart of a method 700 for communicating a grant for retransmission feedback according to some embodiments of the present disclosure. The steps of method 700 may be performed by a computing device (e.g., a processor, processing circuitry, and / or other suitable components) of a wireless communication device or other suitable means for performing the steps. For example, a wireless communication device (such as UE 115 or UE 500) may utilize one or more components (such as a processor 502, a memory 504, a signal module 505, a grant module 507, a feedback module 509, a transceiver 510, a modem 512, and / or one or more antennas 516) to perform the steps of method 700. In another example, a wireless communication device (such as BS 105 or BS 600) may utilize one or more components (such as a processor 602, a memory 604, a signal module 605, a grant module 607, a feedback module 609, a transceiver 610, a modem 612, and / or one or more antennas 616) to perform the steps of method 700. Method 700 may be implemented in accordance with the respective embodiments of the present disclosure. Figure 2 、 3 4. As illustrated, method 700 includes several enumerated steps, but various embodiments of method 700 may include additional steps before, after, and between these enumerated steps. In some embodiments, one or more of these enumerated steps may be omitted or performed in a different order.

[0092] At step 710, method 700 includes communicating a first communication signal with a wireless communication device. In one example, the first communication signal is transmitted via a PDSCH. At step 720, method 700 includes communicating a grant to retransmit feedback associated with the first communication signal with the wireless communication device. At step 730, method 700 includes communicating feedback with the wireless communication device based on the grant.

[0093] In some examples, a first wireless communication device may communicate a second grant to transmit feedback associated with a first communication signal to a second communication device. The second grant may be communicated before the first grant for retransmitting the feedback. The first wireless communication device may communicate a DCI indicating the second grant to the second communication device. Additionally, the first wireless communication device may perform LBT in an unlicensed spectrum to communicate feedback based on the second grant. LBT may cause LBT to fail. Accordingly, the first wireless communication device may not be able to communicate feedback based on the second grant (e.g., due to missed feedback opportunities). The first wireless communication device may perform LBT using a first beam to communicate the feedback. In one example, the first wireless communication device communicates feedback based on the first grant using a second beam different from the first beam. In this example and with reference to Figure 3 , the first wireless communication device may use different beams (e.g., transmit beam 311a and transmit beam 311b, respectively) to communicate PUCCH 316a and PUCCH 316b. In another example, the first wireless communication device communicates feedback based on the first grant using the first beam. In this example and with reference to Figure 3 , the first wireless communication device may communicate PUCCH 316a and PUCCH 316b using the same beam (eg, transmit beam 311a).

[0094] In some examples, a first wireless communication device may communicate a second communication signal with a second wireless communication device. A grant for retransmitting feedback for the first communication signal may also be used to transmit second feedback associated with the second communication signal. The first wireless communication device may communicate the second feedback with the second wireless communication device based on the grant. In one example, the first wireless communication device may communicate the first feedback in a first time slot and the second feedback in a second time slot during a first TXOP. The first time slot and the second time slot may correspond to the same time slot or different time slots. Additionally, the first and second time slots may be configured by two different acknowledgement resource indicators (ARIs), respectively. In one example, the wireless communication device may communicate the grant by communicating a first acknowledgement resource indicator (ARI) indicating a first resource for the first feedback in the first time slot and communicating a second ARI indicating a second resource for the second feedback in the second time slot. The first resource and the second resource may be UL resources.

[0095] In one example, the first wireless communication device may communicate the first feedback using a first beam and communicate the second feedback using a second beam different from the first beam. In another example, the first wireless communication device may communicate the first and second feedback using the same beam.

[0096] Information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0097] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or executed with a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0098] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, each function may be stored on or transmitted by a computer-readable medium as one or more instructions or codes. Other examples and implementations fall within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features implementing the functions may also be physically located in various locations, including being distributed so that parts of the functions are implemented at different physical locations. In addition, as used herein (including in the claims), "or" used in an enumeration of items (e.g., an enumeration of items with a phrase such as "at least one of" or "one or more of") indicates an inclusive enumeration, such that, for example, an enumeration of [at least one of A, B, or C] means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

[0099] As will be appreciated by those skilled in the art and depending on the specific application at hand, many modifications, substitutions, and variations can be made in the materials, devices, configurations, and methods of use of the apparatus of the present disclosure without departing from the spirit and scope of the present disclosure. In view of this, the scope of the present disclosure should not be limited to the specific embodiments illustrated and described herein (as these are merely examples of the present disclosure), but should be fully commensurate with the appended claims and their functional equivalents.

Claims

1. A device comprising: Memory; transceiver; as well as at least one processor coupled to the memory and the transceiver, wherein the apparatus is configured to: communicating a downlink control information (DCI) message with a second wireless communication device, the DCI message scheduling a first communication signal and including a second grant for transmitting first feedback associated with the first communication signal; communicating with the second wireless communication device a first grant to transmit the first feedback associated with the first communication signal, the second grant being communicated before the first grant to transmit the first feedback, wherein the first grant includes a Physical Uplink Control Channel (PUCCH) trigger and the first grant does not schedule Physical Downlink Shared Channel (PDSCH) communications; and The first feedback is communicated with the second wireless communication device based on the first grant. 2 . The apparatus of claim 1 , wherein the first feedback comprises at least one of an acknowledgment (ACK) indicating that the first communication signal was received without error, or a negative acknowledgment (NACK). The apparatus of claim 1 , wherein the first communication signal is conveyed via a physical downlink shared channel (PDSCH). 4 . The apparatus of claim 1 , wherein the PUCCH trigger comprises a hybrid automatic repeat request (HARQ) acknowledgement (ACK) request.

5. The apparatus of claim 1 , wherein the apparatus is further configured to: A listen-before-talk (LBT) procedure is performed in an unlicensed spectrum based on a second grant for communicating the first feedback, wherein performing the LBT results in an LBT failure.

6. The apparatus of claim 5, wherein the apparatus is further configured to: performing the LBT procedure using a first beam for communicating the first feedback; and The first feedback is communicated based on the first grant using a second beam different from the first beam.

7. The apparatus of claim 1 , wherein the apparatus is further configured to: The DCI message is transmitted to the second wireless communication device.

8. The apparatus of claim 1 , wherein the apparatus is further configured to: The first grant is transmitted to the second wireless communication device.

9. The apparatus of claim 1 , wherein the apparatus is further configured to: The first feedback is received from the second wireless communication device.

10. The apparatus of claim 1 , wherein the apparatus is further configured to: The first feedback is received from the second wireless communication device in an uplink data portion of a time slot.

11. The apparatus of claim 1 , wherein the apparatus is further configured to: The first feedback is received from the second wireless communication device in an uplink control portion of a time slot.

12. A method of wireless communication, comprising: communicating, by a first wireless communication device and a second wireless communication device, a downlink control information (DCI) message, the DCI message scheduling a first communication signal and including a second grant for transmitting first feedback associated with the first communication signal; communicating, by the first wireless communication device and the second wireless communication device, a first grant to transmit the first feedback associated with the first communication signal, the second grant being communicated before the first grant to transmit the first feedback, wherein the first grant includes a Physical Uplink Control Channel (PUCCH) trigger and the first grant does not schedule Physical Downlink Shared Channel (PDSCH) communications; as well as The first feedback is communicated, by the first wireless communication device, with the second wireless communication device based on the first grant.

13. The method of claim 12, wherein communicating the first communication signal comprises communicating the first communication signal via a physical downlink shared channel (PDSCH).

14. The method of claim 12, wherein the PUCCH trigger comprises a hybrid automatic repeat request (HARQ) acknowledgement (ACK) request.

15. The method of claim 12, wherein communicating the first feedback comprises transmitting, by the first wireless communication device, the DCI message to the second wireless communication device.

16. The method of claim 12, wherein communicating the first grant comprises transmitting the first grant by the first wireless communication device to the second wireless communication device.

17. The method of claim 12, wherein communicating the first feedback comprises receiving, by the first wireless communication device, the first feedback from the second wireless communication device.

18. The method of claim 12, wherein communicating the first feedback comprises receiving, by the first wireless communication device, the first feedback from the second wireless communication device in an uplink data portion of a time slot.

19. The method of claim 12, wherein communicating the first feedback comprises receiving, by the first wireless communication device, the first feedback from the second wireless communication device in an uplink control portion of a time slot.

20. A non-transitory computer-readable medium having program code recorded thereon, the program code comprising: code for causing a first wireless communication device to communicate a downlink control information (DCI) message with a second wireless communication device, the DCI message scheduling a first communication signal and including a second grant for transmitting first feedback associated with the first communication signal; code for causing the first wireless communication device to communicate with the second wireless communication device a first grant to transmit the first feedback associated with the first communication signal, the second grant being communicated before the first grant to transmit the first feedback, wherein the first grant includes a Physical Uplink Control Channel (PUCCH) trigger and the first grant does not schedule Physical Downlink Shared Channel (PDSCH) communications; as well as Code for causing the first wireless communication device to communicate the first feedback with the second wireless communication device based on the first grant.

Images