Sidelink communication with hybrid automatic repeat request (HARQ) feedback transmission in unlicensed spectrum

Abstract

Certain aspects of the present disclosure provide techniques for slot formats for sidelink communication. A method executable by a user equipment (UE) includes: transmitting a data signal; suppressing transmission during a gap portion that occurs in time after transmitting the data signal, wherein the gap portion has a duration less than or equal to a threshold; receiving a feedback signal after the gap portion, wherein the feedback signal includes at least one signal and hybrid automatic repeat request (HARQ) feedback for the data signal; receiving another signal; and adjusting a gain applied to the another signal based on the signal.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit and priority of Greek Application No. 20200100364, filed on June 24, 2020, which is incorporated herein by reference in its entirety for all applicable purposes.

[0003] Introduction

[0004] Aspects of the present disclosure relate to wireless communication, and more particularly to techniques for sidelink communication in unlicensed spectrum.

[0005] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasting, etc. These wireless communication systems may employ multiple - access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple - access systems include Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) systems, LTE - Advanced (LTE - A) systems, 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, to name just a few examples.

[0006] These multiple - access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at the urban, national, regional, and even global levels. New Radio (e.g., 5G NR) is an example of an emerging telecommunication standard. NR is an enhanced set of the LTE mobile standard promulgated by 3GPP. NR is designed to better support mobile broadband Internet access by using OFDMA with cyclic prefix (CP) on the downlink (DL) and uplink (UL) to improve spectral efficiency, reduce costs, improve services, utilize new spectrum, and better integrate with other open standards. To this end, NR supports beamforming, multiple - input multiple - output (MIMO) antenna technology, and carrier aggregation.

[0007] However, as the demand for mobile broadband access continues to grow, there is a need for further improvements in NR and LTE technologies. Preferably, these improvements should be applicable to other multiple - access technologies and the telecommunication standards that employ these technologies.

[0008] Summary

[0009] The systems, methods, and devices of the present disclosure each have several aspects, and no single aspect alone is responsible for their desirable attributes. Without limiting the scope of the present disclosure as expressed in the appended claims, some features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled "Detailed Description," it will be understood how the features of the present disclosure provide sidelink communication in unlicensed spectrum.

[0010] Certain aspects of the subject matter described in the present disclosure may be implemented in a method for wireless communication. The method generally includes: transmitting a data signal; suppressing transmission during a gap portion that occurs in time after transmitting the data signal, where the gap portion has a duration less than or equal to a threshold; receiving a feedback signal after the gap portion, where the feedback signal includes at least one signal and hybrid automatic repeat request (HARQ) feedback for the data signal; receiving another signal; and adjusting a gain applied to the another signal based on the signal.

[0011] Certain aspects of the subject matter described in the present disclosure may be implemented in a method for wireless communication. The method generally includes: receiving an indication in sidelink control information (SCI) that hybrid automatic repeat request (HARQ) feedback is enabled for a data signal; receiving the data signal; suppressing transmission during a gap portion that occurs in time after receiving the data signal, where the gap portion has a duration less than or equal to a threshold; and transmitting a feedback signal that includes a signal and HARQ feedback for the data signal.

[0012] Certain aspects of the subject matter described in the present disclosure may be implemented in a device for wireless communication. The device generally includes a memory and a processor coupled to the memory. The processor and the memory are configured to: transmit a data signal, and suppress transmission during a gap portion that occurs in time after transmitting the data signal, where the gap portion has a time duration less than or equal to a threshold, receive a feedback signal after the gap portion, where the feedback signal includes at least one signal and hybrid automatic repeat request (HARQ) feedback for the data signal, receive another signal; adjust a gain applied to the another signal based on the signal.

[0013] Certain aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus generally includes a memory and a processor coupled to the memory. The processor and the memory are configured to: receive an indication in sidelink control information (SCI) that hybrid automatic repeat request (HARQ) feedback is enabled for a data signal, receive the data signal, inhibit transmission during a gap portion that occurs in time after the data signal is received, where the gap portion has a time duration less than or equal to a threshold, and transmit a feedback signal after the gap portion, the feedback signal including a signal and HARQ feedback for the data signal.

[0014] Certain aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus generally includes: means for transmitting a data signal; means for inhibiting transmission during a gap portion that occurs in time after the data signal is transmitted, where the gap portion has a duration less than or equal to a threshold; means for receiving a feedback signal after the gap portion, where the feedback signal includes at least one signal and hybrid automatic repeat request (HARQ) feedback for the data signal; means for receiving another signal; and means for adjusting a gain applied to the another signal based on the signal.

[0015] Certain aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus generally includes: means for receiving an indication in sidelink control information (SCI) that hybrid automatic repeat request (HARQ) feedback is enabled for a data signal; means for receiving the data signal; means for inhibiting transmission during a gap portion that occurs in time after the data signal is received, where the gap portion has a duration less than or equal to a threshold; and means for transmitting a feedback signal, the feedback signal including a signal and HARQ feedback for the data signal.

[0016] Certain aspects of the subject matter described in this disclosure can be implemented in a computer-readable medium for wireless communication. The computer-readable medium includes instructions that, when executed by a processing system, cause the processing system to perform operations that generally include: transmitting a data signal; inhibiting transmission during a gap portion that occurs in time after the data signal is transmitted, where the gap portion has a duration less than or equal to a threshold; receiving a feedback signal after the gap portion, where the feedback signal includes at least one signal and hybrid automatic repeat request (HARQ) feedback for the data signal; receiving another signal; and adjusting a gain applied to the another signal based on the signal.

[0017] Certain aspects of the subject matter described in this disclosure can be implemented in a computer-readable medium for wireless communication. The computer-readable medium includes instructions that, when executed by a processing system, cause the processing system to perform operations that generally include: receiving an indication in side link control information (SCI) that hybrid automatic repeat request (HARQ) feedback is enabled for a data signal; receiving the data signal; suppressing transmission during a gap portion that occurs in time after receiving the data signal, where the gap portion has a duration less than or equal to a threshold; and transmitting a feedback signal that includes a signal and HARQ feedback for the data signal.

[0018] Certain aspects of the subject matter described in this disclosure can be implemented in a method for wireless communication. The method generally includes: transmitting a data signal; suppressing transmission during a gap portion that occurs in time after transmitting the data signal, where the gap portion has a duration less than or equal to a value; and receiving a feedback signal after the gap portion, where the feedback signal includes at least an automatic gain control (AGC) signal and hybrid automatic repeat request (HARQ) feedback for the data signal.

[0019] Certain aspects of the subject matter described in this disclosure can be implemented in a method for wireless communication. The method generally includes: receiving a data signal; suppressing transmission during a gap portion that occurs in time after receiving the data signal, where the gap portion has a duration less than or equal to a value; and transmitting a feedback signal that includes an automatic gain control (AGC) signal and hybrid automatic repeat request (HARQ) feedback for the data signal.

[0020] Certain aspects of the subject matter described in this disclosure can be implemented in a device for wireless communication. The device generally includes: means for transmitting a data signal; means for suppressing transmission during a gap portion that occurs in time after transmitting the data signal, where the gap portion has a duration less than or equal to a value; and means for receiving a feedback signal after the gap portion, where the feedback signal includes at least an automatic gain control (AGC) signal and hybrid automatic repeat request (HARQ) feedback for the data signal.

[0021] Certain aspects of the subject matter described in this disclosure can be implemented in a device for wireless communication. The device generally includes: means for receiving a data signal; means for suppressing transmission during a gap portion that occurs in time after receiving the data signal, where the gap portion has a duration less than or equal to a value; and means for transmitting a feedback signal that includes an automatic gain control (AGC) signal and hybrid automatic repeat request (HARQ) feedback for the data signal.

[0022] Certain aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus generally includes a memory; and a processor coupled to the memory, the memory and the processor being configured to: transmit a data signal; inhibit transmission during a gap portion that occurs in time after the transmission of the data signal, where the gap portion has a duration less than or equal to a value; and receive a feedback signal after the gap portion, where the feedback signal includes at least an automatic gain control (AGC) signal and a hybrid automatic repeat request (HARQ) feedback for the data signal.

[0023] Certain aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus generally includes a memory; and a processor coupled to the memory, the memory and the processor being configured to: receive a data signal; inhibit transmission during a gap portion that occurs in time after the reception of the data signal, where the gap portion has a duration less than or equal to a value; and transmit a feedback signal that includes an automatic gain control (AGC) signal and a hybrid automatic repeat request (HARQ) feedback for the data signal.

[0024] Certain aspects of the subject matter described in this disclosure can be implemented in a computer-readable medium for wireless communication. The computer-readable medium includes instructions that, when executed by a processing system, cause the processing system to perform operations that generally include: transmit a data signal; inhibit transmission during a gap portion that occurs in time after the transmission of the data signal, where the gap portion has a duration less than or equal to a value; and receive a feedback signal after the gap portion, where the feedback signal includes at least an automatic gain control (AGC) signal and a hybrid automatic repeat request (HARQ) feedback for the data signal.

[0025] Certain aspects of the subject matter described in this disclosure can be implemented in a computer-readable medium for wireless communication. The computer-readable medium includes instructions that, when executed by a processing system, cause the processing system to perform operations that generally include: receive a data signal; inhibit transmission during a gap portion that occurs in time after the reception of the data signal, where the gap portion has a duration less than or equal to a value; and transmit a feedback signal that includes an automatic gain control (AGC) signal and a hybrid automatic repeat request (HARQ) feedback for the data signal.

[0026] To achieve the foregoing and related purposes, one or more aspects include the features that are fully described below and particularly pointed out in the claims. The following description and the drawings detail certain illustrative features of one or more aspects. However, these features merely indicate several of the various ways in which the principles of the various aspects can be employed. Brief Description of the Drawings

[0028] To understand the manner in which the above-recited features of the present disclosure can be obtained, a more particular description, in terms of various aspects, can be had with reference to the aspects illustrated in the drawings. It should be noted, however, that the drawings illustrate only certain aspects of the present disclosure and are not to be considered limiting of its scope, as the description may admit to other equally effective aspects.

[0029] Figure 1 is a block diagram conceptually illustrating an example wireless communication network in accordance with certain aspects of the present disclosure.

[0030] Figure 2 is a block diagram conceptually illustrating the design of an example base station (BS) and user equipment (UE) in accordance with certain aspects of the present disclosure.

[0031] Figure 3 is an example frame format for certain wireless communication systems (e.g., New Radio (NR)) in accordance with certain aspects of the present disclosure.

[0032] Figure 4A and Figure 4B illustrate a graphical representation of an example vehicle-to-everything (V2X) system in accordance with certain aspects of the present disclosure.

[0033] Figure 5 is a schematic diagram illustrating an example model of multiple wireless devices operating in an unlicensed spectrum in accordance with certain aspects of the present disclosure.

[0034] Figure 6 is an example transmission timeline for sidelink communication in accordance with certain aspects of the present disclosure.

[0035] Figure 7 is an example transmission timeline for sidelink communication in accordance with certain aspects of the present disclosure.

[0036] Figure 8A and 8B are example transmission timelines for sidelink communication in accordance with aspects of the present disclosure.

[0037] Figure 9A and 9B are example transmission timelines for sidelink communication in accordance with aspects of the present disclosure, with a gap at the end of a time slot.

[0038] Figure 10 is a flowchart illustrating an example operation for wireless communication by a UE in accordance with certain aspects of the present disclosure.

[0039] Figure 11A flowchart illustrates example operations for wireless communication by a UE in accordance with certain aspects of the present disclosure.

[0040] Figure 12 Illustrated are communication devices in accordance with aspects of the present disclosure that may include various components configured to perform the operations in Figure 10 Each operation.

[0041] Figure 13 Illustrated are communication devices in accordance with aspects of the present disclosure that may include various components configured to perform the operations in Figure 11 Each operation.

[0042] For ease of understanding, where possible, the same reference numerals have been used to designate the same elements common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized in other aspects without specific recitation.

[0043] Detailed Description

[0044] Aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for sidelink communication with hybrid automatic repeat request (HARQ) feedback transmission in unlicensed spectrum. Unlicensed spectrum refers to any frequency band that is not subject to licensed use under regulatory practice, such that the band is open for use by any device (not just devices having a license to use the specific band). Example sidelink communication includes vehicle-to-everything (V2X) communication. Although certain aspects may be discussed with respect to V2X communication in a V2X communication system, it should be noted that the aspects may equally apply to other suitable types of sidelink communication systems.

[0045] In some aspects, for wireless communication in unlicensed spectrum, a wireless communication device (e.g., a UE and / or a Wi-Fi device) may perform a channel access procedure known as a listen-before-talk (LBT) procedure, where the device may transmit if the channel corresponding to the frequency band is sensed to be empty (e.g., idle) before transmission. The period of time during which the LBT procedure is performed before transmission may be referred to as a listen opportunity. In the LBT procedure, the wireless communication device measures the energy on the frequency band and refrains from transmitting on the frequency band when the band is busy, and determines that it may communicate on the frequency band when the band is idle. As used herein, the term "idle" for a frequency band means that the energy measured on the frequency band by the device determining the idle state is below a threshold level. As used herein, the term "busy" for a frequency band means that the energy measured on the frequency band by the device determining the idle state is above a threshold level. Such energy may be caused by noise or signals within the frequency band.

[0046] In some aspects, if the time period (e.g., transmission gap) since the device previously transmitted on the unlicensed band is greater than a specific threshold (e.g., 16 μs), the device may perform a LBT procedure on the unlicensed band before transmitting a signal on that unlicensed band.

[0047] In some aspects, sidelink communication may be scheduled with a gap time period (e.g., a gap symbol in a time slot), during which the UE does not transmit or receive. In some aspects, the gap time period may be referred to as a gap symbol. The gap symbol may enable the UE to switch from a receive mode to a transmit mode, or vice versa. The gap symbol may also account for delayed signal communication, such as due to the UE not being synchronized in time, thereby causing propagation delay.

[0048] Sidelink communication may, for example, be enabled with hybrid automatic repeat request (HARQ) feedback to provide a certain quality of service (QoS level). During the HARQ feedback process, the UE transmitting data may retransmit the packet if the previous transmission of the packet fails; for example, the UE may retransmit the packet upon receiving a negative acknowledgment (NACK) feedback in response to the packet from the expected recipient of the packet (e.g., the receiving UE), the negative acknowledgment (NACK) feedback indicating that the expected recipient received but failed to successfully decode the packet.

[0049] Sidelink HARQ feedback transmission in the unlicensed band may also be subject to the availability of the unlicensed band, as discussed with respect to the LBT procedure. In some examples of the HARQ feedback mechanism, physical sidelink feedback channel (PSFCH) resources may be configured in every N time periods (e.g., time slots), where N may be an integer (e.g., 0, 1, 2, or 4). In one example, the HARQ feedback timeline may be n + k, which means that for a physical sidelink shared channel (PSSCH) transmission in time slot n, the receiving UE will transmit HARQ feedback in time slot n + k, where time slot n + k is the first time slot with the allocated PSFCH resources and k ≥ 2. In some examples of the HARQ feedback technique, the PSFCH transmission may occupy two time periods (e.g., symbols) of the time slot. In one or more examples, the PSFCH transmission on the two symbols may be the same, but the UE receiving the PSFCH may decode the second symbol in time and use the first symbol in time for automatic gain control (AGC) training, and the AGC training may be used to adjust the gain applied to the signal received from that particular UE.

[0050] In some cases, a sidelink device may use an automatic gain control signal to account for the near-far effect of the received sidelink signal. The sidelink signals received at the receiving UE from different transmitting devices may vary in power, e.g., due to different distances between the transmitting UE and the receiving UE. The automatic gain control signal may be transmitted by the transmitting UE so that the receiving UE can adjust the gain applied to the received signal.

[0051] In some cases, HARQ feedback transmission resources may not be guaranteed, e.g., due to the unlicensed band being occupied by other wireless communication devices (such as Wi-Fi devices). In accordance with aspects of the present disclosure, techniques are provided for transmitting sidelink data transmissions and sidelink feedback for sidelink data transmissions without performing LBT or other channel sensing of the unlicensed band. For example, after a certain gap period, a receiving UE that has received data and transmitted HARQ feedback for that data may start transmitting a signal (e.g., an AGC signal) to occupy the unlicensed band. While transmitting the AGC signal, the receiving UE may process signals from the transmitting UE, generate HARQ feedback, and transmit the HARQ feedback to the transmitting UE without having to perform LBT to transmit the HARQ feedback. Specifically, the AGC signal continues to occupy the unlicensed band, thereby ensuring that other devices refrain from occupying the unlicensed band so that it is not necessary to perform LBT to ensure that the unlicensed band remains unoccupied. Aspects of the present disclosure may provide HARQ feedback performance, which may contribute to lower latency and / or higher data rates, e.g., due to the ability to send HARQ feedback without performing additional LBT or other channel sensing, as discussed.

[0052] Such techniques may be used, for example, in sidelink communication between wireless communication devices. In other examples, the wireless communication devices may include cellular vehicle-to-everything (CV2X) devices. It should be noted that although certain aspects are described with respect to CV2X devices and communication in the unlicensed band, it will be appreciated that the aspects may similarly apply to other scenarios, such as any communication in the unlicensed band (e.g., sidelink communication), communication in the licensed band (e.g., sidelink communication), and so on.

[0053] The electromagnetic spectrum (such as in a licensed frequency band) is typically subdivided into various classes, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz – 7.125 GHz) and FR2 (24.25 GHz – 52.6 GHz). It should be understood that although a portion of FR1 is greater than 6 GHz, in various documents and articles, FR1 is typically (interchangeably) referred to as the "sub-6 GHz" band. Similar naming issues sometimes arise with respect to FR2. Although different from the extremely high frequency (EHF) band (30 GHz – 300 GHz) identified by the International Telecommunication Union (ITU) as the "millimeter wave" band, FR2 is typically (interchangeably) referred to as the "millimeter wave" band in various documents and articles.

[0054] The frequencies between FR1 and FR2 are generally referred to as mid-band frequencies. Recent 5G NR research has identified the operating bands for these mid-band frequencies as frequency range designation FR3 (7.125 GHz – 24.25 GHz). Bands falling within FR3 can inherit FR1 characteristics and / or FR2 characteristics, and thus effectively extend the features of FR1 and / or FR2 into the mid-band frequencies. Additionally, higher frequency bands are currently being explored to extend 5G NR operation above 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR4a or FR4-1 (52.6 GHz – 71 GHz), FR4 (52.6 GHz – 114.25 GHz), and FR5 (114.25 GHz – 300 GHz). Each of these higher bands falls within the EHF band.

[0055] Taking the above aspects into account, unless otherwise specifically stated, it should be understood that if used in this document, terms such as "sub-6 GHz" can generally represent frequencies that can be less than 6 GHz, can be within FR1, or can include mid-band frequencies. Additionally, unless otherwise specifically stated, it should be understood that if used in this document, terms such as "millimeter wave" can generally represent frequencies that can include mid-band frequencies, can be within FR2, FR4, FR4-a or FR4-1, and / or FR5, or can be within the EHF band.

[0056] The following description provides examples of transmitting sidelink data transmissions and sidelink feedback for sidelink data transmissions in the same time period (e.g., time slot) in a wireless communication system and is not limiting of the scope, applicability, or examples set forth in the claims. Changes may be made to the functionality and arrangements of the elements discussed without departing from the scope of the disclosure. Various examples may appropriately omit, substitute, or add various procedures or components. For example, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with reference to some examples may be combined in some other examples. For example, any number of aspects set forth herein may be used to implement an apparatus or practice a method. Additionally, the scope of the disclosure is intended to cover such apparatus or methods practiced using other structures, functionality, or a combination of structures and functionality that complement or are in addition to the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be implemented by one or more elements of the claims. The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as superior or better than other aspects.

[0057] In general, any number of wireless networks may be deployed in a given geographical area. Each wireless network may support a specific radio access technology (RAT) and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, air interface, etc. A frequency may also be referred to as a carrier, subcarrier, frequency channel, tone, subband, etc. Each frequency may support a single RAT in a given geographical area to avoid interference between wireless networks of different RATs.

[0058] The techniques described herein may be used for various wireless networks and radio technologies. Although aspects may be described herein using terms typically associated with 3G, 4G, and / or new radio (e.g., 5G NR) wireless technologies, aspects of the disclosure may be applied in communication systems based on other generations.

[0059] NR access can support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting broadband widths (e.g., 80 MHz or more than 80 MHz), millimeter wave (mmW) targeting high carrier frequencies (e.g., 24 GHz to 53 GHz or above), massive machine type communication MTC (mMTC) targeting non-backward compatible MTC technologies, and / or mission-critical targeting ultra-reliable low latency communication (URLLC). These services can include latency and reliability requirements. These services can also have different transmission time intervals (TTIs) to meet corresponding quality of service (QoS) requirements. Additionally, these services can coexist in the same subframe. NR supports beamforming and the beam direction can be dynamically configured. MIMO transmission with precoding can also be supported. The MIMO configuration in DL can support up to 8 transmit antennas (multi-layer DL transmission with up to 8 streams) and up to 2 streams per UE. Multi-layer transmission with up to 2 streams per UE can be supported. Up to 8 serving cells can be used to support aggregation of multiple cells.

[0060] Figure 1 An example wireless communication network 100 is illustrated in which aspects of the present disclosure may be implemented. For example, the wireless communication network 100 may be an NR system (e.g., a 5G NR network). As Figure 1 shown, the wireless communication network 100 may be in communication with a core network 132. The core network 132 may be in communication with one or more base stations (BSs) 110 and / or user equipment (UEs) 120 in the wireless communication network 100 via one or more interfaces.

[0061] According to certain aspects, the BS 110 and the UE 120 may be configured for sidelink communication. As Figure 1As shown, UE 120a includes a sidelink manager 122. In some aspects, in accordance with aspects of the present disclosure, the sidelink manager 122: suppresses transmission during a gap portion of a first symbol of a time slot, where the first symbol includes the gap portion and an automatic gain control (AGC) portion, and where the first symbol follows a data signal; receives a signal (e.g., an AGC signal for AGC of a receiving UE) during the AGC portion of the first symbol; and receives hybrid automatic repeat request (HARQ) feedback for the data signal during a second symbol of the time slot, where the second symbol follows the AGC signal (e.g., and is temporally adjacent). For some aspects, the sidelink manager 122 may: transmit a data signal; suppress transmission during a gap portion occurring in time after transmitting the data signal, where the gap portion has a duration less than or equal to a threshold; receive a feedback signal after the gap portion, where the feedback signal includes at least one signal and HARQ feedback for the data signal; and adjust a gain applied to a signal received at a receiver (e.g., the feedback signal and / or a subsequently received signal) based on the signal. In some aspects, the sidelink manager 122 may: receive an indication that HARQ feedback is enabled for a data signal in sidelink control information (SCI); receive the data signal; suppress transmission during a gap portion occurring in time after receiving the data signal, where the gap portion has a duration less than or equal to a value; and transmit a feedback signal that includes a signal and HARQ feedback for the data signal.

[0062] In accordance with aspects of the present disclosure, UE 120b includes a sidelink manager 124 that may represent the sidelink manager 122.

[0063] As Figure 1 illustrated, the wireless communication network 100 may include several BSs 110a-z (each also individually referred to herein as a BS 110, or collectively as BS 110) and other network entities. The BS 110 may provide communication coverage for a particular geographic area (sometimes referred to as a “cell”), which may be stationary or may move according to the location of the mobile BS 110. In some examples, the BSs 110 may be interconnected with each other and / or with one or more other BSs or network nodes (not shown) in the wireless communication network 100 using any suitable transport network via various types of backhaul interfaces (e.g., direct physical connections, wireless connections, virtual networks, etc.). In Figure 1In the example shown, BS 110a, 110b, and 110c can be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x can be a pico BS for pico cell 102x. BSs 110y and 110z can be femto BSs for femto cells 102y and 102z, respectively. A BS can support one or more cells.

[0064] BS 110 communicates with UEs 120a - y in wireless communication network 100 (each also individually referred to herein as UE 120 or collectively as UEs 120). UEs 120 (e.g., 120x, 120y, etc.) can be dispersed throughout wireless communication network 100, and each UE 120 can be stationary or mobile. In one example, a quadcopter, drone, or any other unmanned aerial vehicle (UAV) or remotely piloted aircraft system (RPAS) 120d can be configured to act as a UE. Wireless communication network 100 can also include relay stations (e.g., relay station 110r) (also referred to as relays, etc.), which receive transmissions of data and / or other information from an upstream station (e.g., BS 110a or UE 120r) and send the transmissions of the data and / or other information to a downstream station (e.g., UE 120 or BS 110), or which relay transmissions between UEs 120 to facilitate communication between devices.

[0065] Network controller 130 can communicate with a set of BSs 110 and provide coordination and control of these BSs 110 (e.g., via a backhaul). In various aspects, network controller 130 can be in communication with core network 132 (e.g., 5G core network (5GC)), which provides various network functions such as access and mobility management, session management, user plane function, policy control function, authentication server function, unified data management, application function, network exposure function, network repository function, network slice selection function, etc.

[0066] Figure 2 Illustrates example components of BS 110a and UE 120a (e.g., Figure 1 of wireless communication network 100) that can be used to implement aspects of the present disclosure.

[0067] At BS 110a, the transmit processor 220 may receive data from the data source 212 and control information from the controller / processor 240. This control information may be used for the physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical hybrid ARQ indicator channel (PHICH), physical downlink control channel (PDCCH), group common PDCCH (GC PDCCH), etc. This data may be used for the physical downlink shared channel (PDSCH), etc. Media access control (MAC)-control element (MAC-CE) is a MAC layer communication structure that can be used for the exchange of control commands between wireless nodes. The MAC-CE may be carried in a shared channel, such as the physical downlink shared channel (PDSCH), physical uplink shared channel (PUSCH), or physical sidelink shared channel (PSSCH).

[0068] The processor 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols (such as for the primary synchronization signal (PSS), secondary synchronization signal (SSS), PBCH demodulation reference signal (DMRS), and channel state information reference signal (CSI-RS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, control symbols, and / or reference symbols, if applicable, and may provide the output symbol streams to the modulators (MOD) 232a - 232t. Each modulator 232 may process its respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signals from the modulators 232a - 232t may be transmitted via the antennas 234a - 234t, respectively.

[0069] At UE 120a, antennas 252a - 252r may receive downlink signals from BS 110a and may provide the received signals to demodulators (DEMOD) 254a - 254r in the transceiver, respectively. Each demodulator 254 may condition (e.g., filter, amplify, down-convert, and digitize) its respective received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. The MIMO detector 256 may obtain received symbols from all demodulators 254a - 254r, perform MIMO detection on these received symbols when applicable, and provide detected symbols. The receive processor 258 may process (e.g., demodulate, de-interleave, and decode) these detected symbols, provide the decoded data for UE 120a to the data sink 260, and provide the decoded control information to the controller / processor 280.

[0070] On the uplink, at UE 120a, the transmit processor 264 may receive and process data from the data source 262 (e.g., for the physical uplink shared channel (PUSCH)) and control information from the controller / processor 280 (e.g., for the physical uplink control channel (PUCCH)). The transmit processor 264 may also generate reference symbols for reference signals (e.g., sounding reference signals (SRS)). The symbols from the transmit processor 264 may be precoded by the TX MIMO processor 266 when applicable, further processed by modulators 254a - 254r in the transceiver (e.g., for SC - FDM, etc.), and transmitted to BS 110a. At BS110a, the uplink signal from UE 120a may be received by the antenna 234, processed by the modulator 232, detected by the MIMO detector 236 when applicable, and further processed by the receive processor 238 to obtain the decoded data and control information transmitted by UE 120a. The receive processor 238 may provide the decoded data to the data sink 239 and the decoded control information to the controller / processor 240.

[0071] Memories 242 and 282 may store data and program codes for BS 110a and UE 120a, respectively. The scheduler 244 may schedule the UE for data transmission on the downlink and / or uplink.

[0072] The antennas 252, processors 266, 258, 264, and / or the controller / processor 280 of UE 120a, and / or the antenna 234, processors 220, 230, 238, and / or the controller / processor 240 of BS 110a may be used to perform the various techniques and methods described herein. For example, as Figure 2As shown in, according to aspects described herein, the controller / processor 280 of UE 120a has a sidelink manager 281 that can represent sidelink managers 122, 124. Although shown at the controller / processor, other components of UE 120a and BS 110a can also be used to perform the operations described herein.

[0073] NR can utilize Orthogonal Frequency Division Multiplexing (OFDM) with a Cyclic Prefix (CP) on both the uplink and downlink. NR can support half-duplex operation using Time Division Duplex (TDD). OFDM and Single-Carrier Frequency Division Multiplexing (SC-FDM) divide the system bandwidth into multiple orthogonal subcarriers, which are also often referred to as frequency tones, frequency bins, etc. Each subcarrier can be modulated with data. Modulation symbols can be transmitted using OFDM in the frequency domain and using SC-FDM in the time domain. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers can depend on the system bandwidth. The minimum resource allocation (so-called Resource Block (RB)) can be 12 consecutive subcarriers. The system bandwidth can also be divided into subbands. For example, one subband can cover multiple RBs. NR can support a base Subcarrier Spacing (SCS) of 15KHz, and other SCSs (e.g., 30kHz, 60kHz, 120kHz, 240kHz, etc.) can be defined relative to the base SCS.

[0074] Figure 3 is a diagram showing an example of a frame format 300 for NR. The transmission timeline for each of the downlink and uplink can be divided into radio frames. Each radio frame can have a predetermined duration (e.g., 10 ms), and can be divided into 10 subframes with indices 0 to 9, each subframe being 1 ms. Each subframe can contain a variable number of time slots (e.g., 1, 2, 4, 8, 16,... time slots), depending on the SCS. Each time slot can include a variable number of symbol periods (e.g., 7, 12, or 14 symbols), depending on the SCS. An index can be assigned to the symbol periods in each time slot. A mini-slot (which can be referred to as a sub-slot structure) refers to a transmission time interval having a duration less than that of a time slot (e.g., 2, 3, or 4 symbols). Each symbol in a time slot can indicate the link direction for data transmission (e.g., DL, UL, or flexible), and the link direction for each subframe can be switched dynamically. The link direction can be based on the time slot format. Each time slot can include DL / UL data as well as DL / UL control information. In some aspects, the feedback channel can occupy at least two symbols of the time slots of frame format 300.

[0075] In NR, Synchronization Signal Blocks (SSBs) are transmitted. In some aspects, each SSB can be transmitted in a burst, where each SSB in the burst corresponds to a different beam direction for UE-side beam management (e.g., including beam selection and / or beam refinement). The SSB includes the PSS, SSS, and a two-symbol PBCH. The SSB can be transmitted in fixed time slot positions (such as Figure 3 symbols 0-3 shown in

[0076] Figure 4A ). The PSS and SSS can be used by the UE for cell search and acquisition. The PSS can provide half-frame timing, and the SSS can provide the CP length and frame timing. The PSS and SSS can provide cell identity. The PBCH carries some basic system information, such as the downlink system bandwidth, timing information within the radio frame, SS burst set periodicity, system frame number, etc. The SSB can be organized into SS bursts to support beam sweeping. Further system information (such as the Remaining Minimum System Information (RMSI), System Information Block (SIB), Other System Information (OSI)) can be transmitted on the Physical Downlink Shared Channel (PDSCH) in certain subframes. The SSB can be transmitted up to 64 times, e.g., up to 64 different beam directions for millimeter wave. Multiple transmissions of the SSB are referred to as an SS burst set. The SSBs in an SS burst set can be transmitted in the same frequency region, while the SSBs in different SS burst sets can be transmitted in different frequency regions. and Figure 4B show a graphical representation of an example V2X system according to some aspects of the present disclosure. For example, Figure 4A and Figure 4B the vehicles shown in can communicate via sidelink channels and can relay sidelink transmissions as described herein. The V2X system can be an example of the sidelink communication system discussed herein, and vehicles and other devices can be configured to communicate via sidelink frequency channels as discussed herein.

[0077] Figure 4A and Figure 4B The V2X systems provided in offer two complementary transmission modes. In Figure 4A the first transmission mode (also referred to as Mode 4) shown as an example in involves direct communication (e.g., also referred to as sidelink communication) between participants in a local area that are in proximity to each other. In Figure 4B the second transmission mode (also referred to as Mode 3) shown as an example in involves network communication through a network, which can be achieved through the Uu interface (e.g., a wireless communication interface between a Radio Access Network (RAN) and a UE).

[0078] Referring to Figure 4A, the V2X system 400 (e.g., including vehicle-to-vehicle (V2V) communication) is illustrated with two vehicles 402, 404. The first transmission mode allows direct communication between different parties in a given geographical location. As illustrated, a vehicle may have a wireless communication link 406 (V2P) with an individual (e.g., via a UE) through a PC5 interface. Communication between vehicles 402 and 404 may also occur through the PC5 interface 408. Communication from vehicle 402 to other highway components (e.g., highway component 410, such as a traffic signal or sign) (V2I) may occur in a similar manner through the PC5 interface 412. For Figure 4A each communication illustrated in

[0079] Figure 4B , two-way communication may occur between the elements, so each element may be a transmitter and a receiver of information. The V2X system 400 may be a self-managed system implemented without the assistance of a network entity. The self-managed system may achieve improved spectral efficiency, reduced cost, and increased reliability because no network service interruption occurs during handover operations for mobile vehicles. The V2X system may be configured to operate in licensed or unlicensed spectrum, whereby any vehicle equipped with the system may access a shared frequency and share information. Such coordinated / shared spectrum operation allows for safe and reliable operation.

[0080] Road Side Units (RSUs) can be utilized. RSUs can be used for V2I communication. In some examples, an RSU can act as a relay node to extend the coverage of a UE. In some examples, an RSU can be co-located with a BS or can be stand-alone. RSUs can have different classifications. For example, RSUs can be classified as UE-type RSUs and micro-node B-type RSUs. The micro B-node type RSU has functionality similar to that of a macro eNB or gNB. The micro B-node type RSU can utilize the Uu interface. UE-type RSUs can be used to meet strict Quality of Service (QoS) requirements by minimizing collisions and improving reliability. UE-type RSUs can use a centralized resource allocation mechanism to allow for efficient resource utilization. Key information (such as traffic conditions, weather conditions, congestion statistics, sensor data, etc.) can be broadcast to UEs in the coverage area. A relay can re-broadcast the key information received from some UEs. UE-type RSUs can be a reliable synchronization source.

[0081] Figure 5 FIG. is a schematic diagram of an example network 500 of multiple CV2X devices operating in unlicensed spectrum. The unlicensed spectrum can be an example of sidelink spectrum. Additionally, network 500 can be an example of a sidelink communication system. The CV2X devices 502 can be configured to communicate on a sidelink frequency channel as discussed herein. For example, any one of these CV2X devices 502 can communicate with any other of these CV2X devices 502.

[0082] In the example illustrated, seven CV2X devices (e.g., a first CV2X device 502a, a second CV2X device 502b, a third CV2X device 502c, a fourth CV2X device 502d, a fifth CV2X device 502e, a sixth CV2X device 502f, and a seventh CV2X device 502g - collectively referred to as CV2X devices 502) can operate in unlicensed spectrum with other non-CV2X devices (e.g., non-CV2X devices 504a-c - collectively referred to as non-CV2X devices 504). In some examples, the first CV2X device 502a, the sixth CV2X device 502f, and the third CV2X device 502c can be part of a platoon or formation. In transportation, platooning or convoying is a method of driving a group of vehicles together. This means increasing the road capacity via an automated highway system. Platooning reduces the distance between cars or trucks (such as based on SL communication).

[0083] Although the examples provided illustrate six automotive CV2X devices and a drone or other aerial vehicle CV2X device in a traffic setting, it will be appreciated that the CV2X devices and environments can extend beyond these and include other wireless communication devices and environments. For example, CV2X device 502 can include a UE (e.g., Figure 1 UE 120) operated by a highway authority and / or a roadside unit (RSU), and can be a device implemented on a motorcycle or carried by a user (e.g., pedestrian, cyclist, etc.), or can be implemented on another aerial vehicle (such as a helicopter).

[0084] CV2X device 502 can include a UE (e.g., Figure 1 UE 120), and can be a device implemented on a motor vehicle or carried by a user (e.g., pedestrian, cyclist, etc.), or be implemented as a roadside unit.

[0085] In some aspects, sidelink communication (e.g., vehicle-to-everything (V2X) communication) can occur in a time-division duplex (TDD) manner. That is, UEs communicating on the sidelink transmit and receive sidelink signals in the same carrier or frequency band, but transmit at a different time than they receive. When a user equipment (UE) communicates in TDD mode, in some aspects, the UE can be scheduled to neither transmit nor receive during a period (e.g., a gap period, which can be a gap symbol) so that the hardware of the UE (e.g., radio front end) can switch from a transmit (Tx) mode to a receive (Rx) mode, or vice versa. In some aspects, sidelink communication can be decoupled from synchronization, which means they are not synchronized in time because there may not be a central unit providing synchronization. For example, a receiving UE can receive a sidelink transmission from device A (e.g., another UE), but can be synchronized with device B (e.g., another UE, a base station (BS), or a global navigation satellite system (GNSS)). Decoupling can result in a propagation delay of an unknown length at the receiving UE for a sidelink transmission from device A, for example, due to differences in synchronization sources. The gap period can accommodate such propagation delays because no content is scheduled for transmission or reception during the gap period, and the receiving UE can receive the delayed signal during the gap period without conflicting with other communications.

[0086] In some aspects, such as in certain CV2X systems, the last symbol in time within a time slot may be reserved as a gap period (referred to as a gap symbol) for certain UEs, which means that there may be no signals scheduled for transmission in the gap symbol and the UE may not be scheduled to receive in the gap symbol. The gap symbol may provide the UE with sufficient time to switch, for example, from the Tx (or Rx) mode to the Rx (or Tx) mode. In some aspects, when a time slot is configured with physical sidelink feedback channel (PSFCH) resources (for hybrid automatic repeat request (HARQ) feedback), there may be two OFDM symbols reserved as gaps (see the description with reference to Figure 6 below).

[0087] In some aspects, sidelink communication may have a near - far effect. For example, in the case where the transmitting UE is closer to the receiving UE (e.g., 100 meters), the receiving UE receives the transmission with a higher power compared to when the transmitting UE is farther from the receiving UE (e.g., 1 kilometer). Thus, the received signal power may vary across time slots at the receiving UE. In some aspects, the first symbol in time within a time slot (or transmission) may be used for automatic gain control (AGC) training to adjust the gain used by the UE for transmission to accommodate the near - far effect. In some aspects, the receiving UE may not decode the AGC symbol, and thus the AGC symbol does not have to carry useful information. For example, in some aspects, the AGC symbol may be a copy of the next symbol transmitted within the time slot.

[0088] Figure 6 is an example transmission timeline 650 for sidelink communication. In the transmission timeline 650, PSFCH resources are configured in symbol 664. A UE (e.g., Figure 1 UE 120a shown in Figure 1 ) transmits a physical sidelink control channel (PSCCH) 652, and the PSCCH 652 allocates other symbols within time slot 680 for a physical sidelink shared channel (PSSCH) 654. As previously mentioned, the UE copies OFDM symbol 660 into the symbol at 662 for use as an AGC symbol. Another UE (e.g., Figure 1 UE120b shown in

[0089] ) receives the PSCCH 652 and the PSSCH 654. This other UE transmits HARQ feedback regarding the PSSCH 654 on the PSFCH during symbol 664. This other UE copies OFDM symbol 664 into symbol 666 for use as an AGC symbol. These two UEs suppress transmission during the last symbol 670 of the time slot and during symbol 672 before (e.g., and temporally adjacent to) the AGC symbol 666.

[0089] The UE may transmit data packets (e.g., in the PSSCH) and expect HARQ feedback from one (in the case of unicast transmission of data packets) or multiple (in the case of multicast transmission of data packets) receiving UEs (e.g., in the PSFCH).

[0090] The receiving UE may require a minimum amount of time to decode the data transmission; in other words, the receiving UE may not be able to transmit HARQ feedback immediately following the data channel reception. For example, if the receiving UE receives a data transmission in time slot n, the receiving UE may be ready to transmit HARQ feedback in a later time slot n+k. However, transmitting HARQ feedback is also subject to LBT in unlicensed spectrum. Thus, due to processing at the receiving UE, there may be a gap between the end of the PSSCH transmission and the start of the PSFCH transmission in response to the PSSCH transmission. In some cases, if this gap is greater than a threshold, the UE (e.g., the UE that transmitted the PSSCH and the UE that received the PSSCH) cannot assume that the channel is still available for HARQ feedback transmission and will thus perform LBT; it is possible that the channel is no longer available for HARQ feedback transmission (e.g., occupied by other technologies or devices).

[0091] In some cases, the threshold for the gap may be 16 microseconds (μs), meaning that if the gap exceeds 16 μs, the transmitting device (e.g., UE) will perform LBT. In some cases, the threshold for the gap may vary depending on the region.

[0092] Figure 7 is an example transmission timeline 700 that illustrates the above sidelink feedback technique. Timeline 700 illustrates time slots n-1 to n+k, and each time slot may have a time slot structure according to Figure 6 shown for one time slot. In this example transmission timeline, a first UE (e.g., UE 120a in wireless communication network 100) transmits a PSSCH to a second UE (e.g., UE 120b in wireless communication network 100) in time slot 702. In time slot 704, the second UE may be scheduled to transmit feedback to the first UE, as discussed. Since the transmission of HARQ feedback is subject to the LBT procedure, the channel may not be idle for feedback transmission, which may delay retransmission from the first UE to the second UE.

[0093] Accordingly, some aspects provide techniques and apparatus for transmitting sidelink data transmissions and sidelink feedback for sidelink data transmissions in a wireless communication system without requiring the receiving UE to perform LBT before transmitting feedback.

[0094] Example sidelink communication for HARQ feedback transmission in unlicensed spectrum

[0095] Aspects of the present disclosure provide techniques for sidelink communication for hybrid automatic repeat request (HARQ) feedback transmission in an unlicensed band. In some aspects of the present disclosure, a first UE may transmit a sidelink data transmission and receive, from a second UE that received the sidelink data transmission, a signal containing corresponding sidelink feedback after a gap not greater than a threshold. Similarly, the second UE may receive the sidelink data transmission, refrain from transmitting during a gap not greater than the threshold, and transmit, after the gap, a signal containing corresponding sidelink feedback information.

[0096] In accordance with aspects of the present disclosure, a UE transmitting data transmits data in an unlicensed spectrum for sidelink communication, and one or more UEs receiving the data may receive the data transmission from the transmitting UE. Aspects of the present disclosure may provide HARQ feedback techniques, which may result in, for example, lower latency and / or higher data rates due to the ability of the receiving UE to send HARQ feedback without performing LBT or other channel sensing.

[0097] In some aspects of the present disclosure, if HARQ feedback is enabled (e.g., requested by the UE transmitting data via sidelink control information), a feedback signal containing the signal and HARQ feedback may be transmitted (e.g., by one or more UEs receiving the data) after data reception; transmission of the feedback signal containing HARQ feedback may be after a gap not greater than (e.g., less than or equal to) a threshold. In some aspects, the signal may be used by the receiving UE to perform AGC and is referred to as an AGC signal. Thus, the unlicensed band is continuously occupied by the UE transmitting data (transmitting data) and the UE receiving the data (transmitting HARQ feedback), and the UE (e.g., the receiving UE) may transmit HARQ feedback without performing LBT or other channel sensing on the unlicensed band.

[0098] In accordance with aspects of the present disclosure, there may be a gap between a data transmission (e.g., PSSCH) of a UE transmitting data and a transmission (e.g., PSFCH containing an AGC signal and HARQ feedback) of a UE receiving the data, as long as the gap is not greater than a threshold (e.g., 16 μs or a gap for turnaround), which may be a threshold (e.g., as specified in a wireless communication standard and / or regulations for wireless communication in an unlicensed spectrum).

[0099] In some aspects of the present disclosure, a UE receiving data may transmit an AGC signal in a symbol (e.g., referred to as an AGC symbol) before (e.g., and adjacent to) the HARQ feedback transmission.

[0100] According to certain aspects of the present disclosure, an AGC signal (e.g., an AGC signal transmitted before (e.g., and adjacent to) HARQ feedback) may carry predetermined information (e.g., a configured sequence), such that the content of the AGC signal does not depend on the PSSCH decoding result, and the UE receiving the data can transmit the AGC signal after (e.g., immediately) receiving the PSSCH. That is, since the UE receiving the data transmits predetermined information in the AGC signal instead of replicating the signal transmitted in subsequent symbols (see Figure 6 ), the UE receiving the data can transmit the AGC before the UE has completed decoding the PSSCH and is ready for (e.g., HARQ feedback in the PSFCH).

[0101] In certain aspects of the present disclosure, while transmitting the AGC signal, the UE receiving the data may perform PSSCH decoding and PSFCH processing.

[0102] According to aspects of the present disclosure, the UE receiving the data may transmit HARQ feedback (e.g., PSFCH) after the AGC signal transmission.

[0103] In aspects of the present disclosure, the gap duration is less than a threshold (e.g., 16 μs or 25 μs or another threshold, such as may be specified by a regional regulator), such that the UE receiving the data can access the unlicensed band and transmit the (a) feedback signal. For example, the UE receiving the data can transmit the AGC signal and HARQ feedback after the gap (less than the threshold) without performing LBT.

[0104] Figure 8A and 8BExamples of transmission timelines 800 and 850 for sidelink communication in accordance with aspects of the present disclosure are shown. In transmission timeline 800, HARQ feedback in response to sidelink data transmission 802 during slot 830 from a UE (e.g., UE 120a) is mapped to HARQ feedback 820 in slot 830, which may have a duration of one symbol. The UE also transmits an AGC signal 822, which may occupy less than two symbols 804 in the slot. There is a gap 810 between the sidelink data transmission and the combination of AGC and PSFCH transmissions. That is, the UE may transmit a feedback signal 840 including HARQ feedback 820 and AGC signal 822 after gap 810. In some aspects, the gap is no greater than a threshold (e.g., 16 μs or 25 μs), such that the UE may transmit AGC and HARQ feedback without performing LBT, as discussed. Thus, in some aspects, the AGC signal transmission may occupy a portion of a symbol duration such that a gap no greater than the threshold may be accommodated before a portion of the AGC signal (e.g., the AGC symbol may have an extended CP length; the symbol after the data transmission may include the gap and a portion of the extended CP length). A total of three symbols are used for the combination of the gap, AGC, and HARQ feedback, and thus the UE receiving the data has two symbol times (e.g., including the gap and AGC) for PSSCH decoding and HARQ feedback processing. At the start of slot 830, one symbol 812 may be used as another gap, as an AGC symbol, or for data transmission.

[0105] In transmission timeline 850, HARQ feedback 870 transmitted by a UE (e.g., UE 120b in wireless communication network 100) is mapped to symbol 872 in slot 880. In this example, the UE also transmits an AGC signal 874 in symbol 866. There is a gap 865 between sidelink data transmission 852 and feedback signal 890 including AGC signal 874 and HARQ feedback signal 870. In some aspects, the AGC signal may only occupy a portion of one symbol, such that the gap may be at the start of the symbol accommodating the AGC signal. In this example, a total of two symbols are used for the combination of the gap, AGC signal, and HARQ feedback, and thus the UE receiving the data has one symbol time (e.g., including the gap and AGC) for PSSCH decoding and PSFCH processing. At the start of the slot, one symbol 862 may be used as another gap, as an AGC symbol, or for data transmission.

[0106] Figure 9A and 9Bare example transmission timelines 900 and 950 for sidelink communication according to aspects of the present disclosure, with a gap at the end of a time slot. In transmission timeline 900, HARQ feedback 920 in response to sidelink data transmission 902 during time slot 930 from a UE (e.g., UE 120a) is mapped to symbol 922 in that time slot. The UE also transmits an AGC signal 924, which may occupy more than two symbols 904 in time slot 930. There is a gap 910 between sidelink data transmission 902 and feedback signal 940 including AGC signal 924 and HARQ feedback 920. In some aspects, the gap is no greater than a threshold (e.g., 16 μs or 25 μs), such that the UE can transmit AGC and PSFCH without performing LBT. Thus, in some aspects, a portion of the AGC symbol can be replicated and transmitted earlier than symbol 904 such that the gap time is no greater than the threshold (e.g., the AGC symbol can have an extra long cyclic prefix (CP) length). In some aspects, a total of 3 symbols are used for the combination of the gap, AGC, and HARQ feedback, and thus the UE receiving the data has 2 symbols of time (e.g., including the gap and AGC) for PSSCH decoding and PSFCH processing. At the beginning of the time slot, one symbol 912 can be used as another gap, as an AGC symbol, or for data transmission. Another gap can be included in the last symbol 926 of the time slot.

[0107] In transmission timeline 950, HARQ feedback 970 transmitted by a UE (e.g., UE 120b in wireless communication network 100) is mapped to symbol 972 in time slot 980. The UE also transmits an AGC signal 974 in symbol 966. There is a gap 965 between sidelink data transmission 952 and feedback signal 990 including AGC signal 974 and HARQ feedback 970. The AGC signal may only occupy a portion of the symbol, such that the gap can be at the beginning of the symbol accommodating the AGC symbol. A total of 2 symbols are used for the combination of the gap, AGC, and HARQ feedback, and thus the UE receiving the data has 1 symbol of time (e.g., including the gap and AGC) for PSSCH decoding and PSFCH processing. At the beginning of the time slot, one symbol 962 can be used as another gap, as an AGC symbol, or for data transmission. Another gap can be included in the last symbol 976 of the time slot.

[0108] Although Figure 8A-8B and the examples shown in 9A - 9B show the combination of the gap and the AGC signal as occupying 1 symbol (e.g., Figure 8B 865 and 866 in Figure 9B and 965 and 966 in Figure 8A or 2 symbols (e.g., Figure 9A904 and 910 in), but the present disclosure is not limited thereto, and the combination of the gap and the AGC signal may occupy other numbers N of symbols, where N is greater than 2. In such cases, a portion of the N symbols may include a gap, and the remaining portion may include an AGC signal.

[0109] In aspects of the present disclosure, HARQ feedback transmission may be enabled by a UE transmitting data. For example, a UE transmitting data may indicate a request for HARQ feedback in sidelink control information (SCI).

[0110] In certain aspects of the present disclosure, if HARQ feedback is requested, a UE receiving data stops receiving from the UE transmitting data at a configured symbol. For example, another UE or the UE transmitting data provides, via the SCI, the duration or common configuration of a data signal to the UE receiving data, which indicates the last symbol in a time slot available for data transmission. For example, the UE receiving data may be (pre)configured or scheduled such that the last symbol for data transmission is the 11th symbol in a time slot (e.g., for symbols in a time slot with a normal cyclic prefix (CP) length), and if HARQ feedback is requested, the UE receiving data switches to a transmit mode after the 11th symbol and then transmits an AGC signal and HARQ feedback, as previously discussed.

[0111] In aspects of the present disclosure, if HARQ feedback is not requested, a UE receiving data may stop receiving from the UE transmitting data at a different configured (e.g., similarly configured via the SCI) symbol. For example, if HARQ feedback is not requested, the UE receiving data may be (pre)configured such that the last symbol for data transmission is the 14th symbol in a time slot (e.g., for a time slot of symbols with a normal CP length).

[0112] In certain aspects of the present disclosure, a UE receiving data knows which symbol is the last symbol in a data transmission after decoding sidelink control signaling (e.g., SCI) scheduling the data transmission and operates accordingly.

[0113] In certain aspects of the present disclosure, the transmission of the AGC signal is independent of the information in the PSFCH or other data channels, such that the transmission of the AGC symbol does not depend on the data channel decoding result. For example, the AGC symbol may carry a predetermined sequence (e.g., a (pre)configured low peak-to-average power ratio (low-PAPR) sequence), as discussed.

[0114] Figure 10 is a flowchart illustrating an example operation 1000 for wireless communication in accordance with certain aspects of the present disclosure. Operation 1000 may be performed, for example, by a UE (e.g., UE 120a in wireless communication network 100). Operation 1000 may be implemented on one or more processors (e.g.,Figure 2 software components that are executed and run on a controller / processor 280). In addition, signal transmission and reception performed by the UE in operation 1000 can be implemented, for example, by one or more antennas (e.g., Figure 2 antenna 252). In some aspects, signal transmission and / or reception performed by the UE can be implemented by obtaining and / or outputting signals via a bus interface of one or more processors (e.g., controller / processor 280).

[0115] Operation 1000 can optionally start at block 1002, where the UE can transmit an indication in sidelink control information (SCI) in a time slot that HARQ feedback is enabled for data signals.

[0116] At block 1004, the UE can transmit a data signal. The data signal can include various contents, such as application data, sensor data, and / or V2X data.

[0117] Operation 1000 can continue at block 1006, where the UE can suppress transmission during a gap portion that occurs in time after transmitting the data signal, where the gap portion has a duration less than or equal to a value (e.g., a threshold).

[0118] Operation 1000 can continue at block 1008, where the UE can receive a feedback signal after the gap portion, where the feedback signal includes at least one signal and hybrid automatic repeat request (HARQ) feedback for the data signal.

[0119] In various aspects, the signal can include an AGC signal. Optionally at block 1010, the UE can receive another signal and adjust the gain applied to the other signal (e.g., (a) subsequent signal) at the receiver based on one or more attributes of the signal (e.g., the received power of the signal). For example, the UE can identify that the received power of the AGC signal is high, and the UE can reduce the gain applied to the signal received from the other UE that transmitted the AGC signal.

[0120] In some such aspects, the SCI further indicates a symbol during which the data signal ends, and the device can also determine another symbol for receiving the feedback signal based on the symbol. That is, the SCI can indicate the symbol during which the data signal ends, and the UE can receive the feedback signal in at least another symbol after the symbol. In other words, the SCI can indicate the duration of the data signal, and the UE can initiate suppression of transmission based on the duration of the data signal.

[0121] In aspects of the present disclosure, the threshold of block 1006 can be one of the following: fixed or configured from a set of candidate values.

[0122] In aspects of the present disclosure, the feedback signal of block 1006 can be received over at least 3 symbols (including the first symbol in time, the second symbol in time, and the third symbol in time), where the gap portion occurs during the first symbol, the AGC signal is received during the first and second symbols, and the HARQ feedback is received during the third symbol. In other words, at block 1008, the UE can receive the feedback signal over at least 3 symbols including the first symbol in time, the second symbol in time, and the third symbol in time, where the gap portion occurs during the first symbol. The UE can receive the signal during the first and second symbols, and receive the HARQ feedback during the third symbol.

[0123] In aspects of the present disclosure, the feedback signal of block 1008 can be received over at least 2 symbols (including the first symbol in time and the second symbol in time), where the gap portion occurs during the first symbol, the AGC signal is received during the first symbol, and the HARQ feedback is received during the second symbol. That is, at block 1008, the UE can receive the feedback signal over at least 2 symbols including the first symbol in time and the second symbol in time, where the gap portion occurs during the first symbol. The UE can receive the signal during the first symbol, and receive the HARQ feedback during the second symbol.

[0124] In aspects of the present disclosure, the feedback signal of block 1006 can be received over a plurality of symbols including the first one or more symbols in time and the second one or more symbols in time, where the gap portion occurs during one of the first one or more symbols, the AGC signal is received during the first one or more symbols, and the HARQ feedback is received during the second one or more symbols. In other words, at block 1008, the UE can receive the feedback signal over a plurality of symbols including the first one or more symbols in time and the second one or more symbols in time, where the gap portion occurs during one of the first one or more symbols. The UE can receive the signal during the first one or more symbols, and receive the HARQ feedback during the second one or more symbols.

[0125] In some aspects, the UE can receive feedback in the same time slot in which the data signal is transmitted. For example, the UE can transmit at least a portion of the data signal in the time slot and refrain from transmitting during the gap portion in the time slot. The UE can receive the feedback signal in the time slot.

[0126] Figure 11is a flowchart illustrating an example operation 1100 for wireless communication in accordance with certain aspects of the present disclosure. Operation 1100 may be performed, for example, by another UE (e.g., UE 120b in wireless communication network 100). Operation 1100 may be complementary to operation 1000 performed by the UE. Operation 1100 may be implemented as a software component executed and run on one or more processors (e.g., Figure 2 controller / processor 280). Further, signal transmission and reception performed by the UE in operation 1100 may be implemented, for example, by one or more antennas (e.g., Figure 2 antenna 252). In certain aspects, signal transmission and / or reception performed by the BS may be implemented by obtaining and / or outputting signals via a bus interface of one or more processors (e.g., controller / processor 280).

[0127] Operation 1100 may begin at block 1102, where the UE may receive an indication in the SCI that HARQ feedback is enabled for a data signal.

[0128] At block 1104, the UE may receive the data signal.

[0129] Operation 1100 may continue at block 1106, where the UE may suppress transmission during a gap portion occurring in time after receiving the data signal, where the gap portion has a duration less than or equal to a value (e.g., a threshold).

[0130] Operation 1100 may continue at block 1108, where the UE may transmit a feedback signal including a signal and HARQ feedback for the data signal. In aspects, the signal may include an AGC signal. For example, the signal may cause the other UE that receives the signal to perform an automatic gain control operation, such as adjusting a gain applied to a signal received at a receiver based on one or more attributes of the signal (e.g., received power of the signal).

[0131] The UE can identify the duration of the data channel (e.g., the symbol position where data transmission ends), so that the UE knows when to stop receiving the data signal. The SCI can indicate whether HARQ feedback transmission for the data channel is enabled, and the UE can implicitly or explicitly determine the data channel duration via the SCI. When the SCI indicates that HARQ feedback is enabled, the UE can determine the data channel duration based on, for example, (pre)-configuration or a certain predetermined rule. In response to receiving the SCI, the UE can identify the gap portion and the signal portion within the time slot based on the indication that HARQ feedback is enabled. In some cases, the SCI can explicitly indicate the duration of the data channel for the data signal. In some such aspects, the SCI further indicates the symbol during which the data signal ends, and the device performing operation 1100 can determine another symbol for transmitting the feedback signal based on this symbol. That is, the SCI can indicate the symbol in which the data signal ends, and the UE can transmit the feedback signal in at least another symbol after this symbol. In other words, the SCI can indicate the duration of the data signal, and the UE can initiate suppression of transmission based on the duration of the data signal.

[0132] In aspects of the present disclosure, the threshold of block 1106 can be one of the following: fixed or configured from a set of candidate values.

[0133] According to aspects of the present disclosure, the feedback signal of block 1108 can be transmitted over at least 3 symbols (including the first symbol in time, the second symbol in time, and the third symbol in time), where the gap portion occurs during the first symbol, the AGC signal is transmitted during the first and second symbols, and the HARQ feedback is transmitted during the third symbol. In other words, in block 1108, the UE can transmit the feedback signal over at least 3 symbols including the first symbol in time, the second symbol in time, and the third symbol in time, where the gap portion occurs during the first symbol. The UE can transmit the signal during the first and second symbols, and transmit the HARQ feedback during the third symbol.

[0134] In aspects of the present disclosure, the feedback signal of block 1108 can be transmitted over at least 2 symbols (including the first symbol in time and the second symbol in time), where the gap portion occurs during the first symbol, the AGC signal is transmitted during the first symbol, and the HARQ feedback is transmitted during the second symbol. That is, in block 1108, the UE can transmit the feedback signal over at least 2 symbols including the first symbol in time and the second symbol in time, where the gap portion occurs during the first symbol. The UE can transmit the signal during the first symbol, and transmit the HARQ feedback during the second symbol.

[0135] In aspects of the present disclosure, the feedback signal of block 1108 may be transmitted over a plurality of symbols including a first one or more symbols in time and a second one or more symbols in time, wherein the gap portion occurs during one of the first one or more symbols, the AGC signal is transmitted during the first one or more symbols, and the HARQ feedback is transmitted during the second one or more symbols. In other words, at block 1108, the UE may transmit a feedback signal over a plurality of symbols including a first one or more symbols in time and a second one or more symbols in time, wherein the gap portion occurs during one of the first one or more symbols. The UE may transmit the signal during the first one or more symbols and transmit the HARQ feedback during the second one or more symbols.

[0136] In aspects of the present disclosure, the AGC signal of block 1108 may include a low peak-to-average power ratio (low-PAPR) sequence.

[0137] In aspects, the UE may transmit the feedback signal in the same time slot in which the data signal is received. For example, the UE may receive a portion of the data signal in a time slot, and the UE may suppress transmission during the gap portion in the time slot and transmit the feedback signal in the time slot.

[0138] Figure 12 Illustrated is a communication device 1200 that may include various components (e.g., corresponding to apparatus-plus-function components) configured to perform operations (such as the operations illustrated in Figure 10 ). The communication device 1200 includes a processing system 1202 coupled to a transceiver 1208 (e.g., a transmitter and / or a receiver). The transceiver 1208 is configured to transmit and receive signals for the communication device 1200 (such as the various signals described herein) via an antenna 1210. The processing system 1202 may be configured to perform processing functions for the communication device 1200, including processing signals received by and / or to be transmitted by the communication device 1200.

[0139] The processing system 1202 includes a processor 1204 coupled to a computer-readable medium / memory 1212 via a bus 1206. In certain aspects, the computer-readable medium / memory 1212 is configured to store instructions that, when executed by the processor 1204, cause the processor 1204 to perform Figure 10Instructions (e.g., computer-executable code) for the operations illustrated herein or for other operations for performing the various techniques discussed herein for having a gap portion and an automatic gain control (AGC) portion within a symbol. In some aspects, the computer-readable medium / memory 1212 stores: code 1214 for transmitting a data signal; code 1216 for suppressing transmission during a gap portion that occurs in time after the transmission of the data signal, where the gap portion has a duration less than or equal to a threshold; code 1218 for receiving a feedback signal after the gap portion, where the feedback signal includes at least an automatic gain control (AGC) signal and hybrid automatic repeat request (HARQ) feedback for the data signal; code 1220 for transmitting an indication in the SCI that HARQ feedback is enabled for the data signal; and / or code 1222 for adjusting the gain applied to a signal received at a receiver (e.g., transceiver 1208) based on the signal. In some aspects, the processor 1204 has circuitry configured to implement the code stored in the computer-readable medium / memory 1212. The processor 1204 includes: circuitry 1224 for transmitting a data signal; circuitry 1226 for suppressing transmission during a gap portion that occurs in time after the transmission of the data signal, where the gap portion has a duration less than or equal to a threshold; circuitry 1228 for receiving a feedback signal after the gap portion, where the feedback signal includes at least an automatic gain control (AGC) signal and hybrid automatic repeat request (HARQ) feedback for the data signal; circuitry 1230 for transmitting an indication in the SCI that HARQ feedback is enabled for the data signal; and / or circuitry 1232 for adjusting the gain applied to a signal received at a receiver (e.g., transceiver 1208) based on the signal.

[0140] Figure 13 Illustrated are various components (e.g., corresponding to apparatus-plus-function components) of a communication device 1300 that may include operations configured to perform the techniques disclosed herein, such as Figure 11 the operations illustrated herein. The communication device 1300 includes a processing system 1302 coupled to a transceiver 1308 (e.g., a transmitter and / or a receiver). The transceiver 1308 is configured to transmit and receive signals for the communication device 1300 (such as the various signals described herein) via an antenna 1310. The processing system 1302 may be configured to perform processing functions for the communication device 1300, including processing signals received by and / or to be transmitted by the communication device 1300.

[0141] The processing system 1302 includes a processor 1304 coupled to a computer-readable medium / memory 1312 via a bus 1306. In some aspects, the computer-readable medium / memory 1312 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 1304, cause the processor 1304 to perform the operations illustrated in Figure 11 or other operations for performing the various techniques discussed herein for having a gap portion and an automatic gain control (AGC) portion within one symbol. In some aspects, the computer-readable medium / memory 1312 stores: code 1314 for receiving a data signal; code 1316 for suppressing transmission during a gap portion that occurs in time after the data signal is received, where the gap portion has a duration less than or equal to a threshold; code 1318 for transmitting a feedback signal that includes an automatic gain control (AGC) signal and a hybrid automatic repeat request (HARQ) feedback for the data signal; and / or code 1320 for receiving an indication in the SCI that HARQ feedback is enabled for the data signal. In some aspects, the processor 1304 has circuitry configured to implement the code stored in the computer-readable medium / memory 1312. The processor 1304 includes: circuitry 1324 for receiving a data signal; circuitry 1326 for suppressing transmission during a gap portion that occurs in time after the data signal is received, where the gap portion has a duration less than or equal to a threshold; circuitry 1328 for transmitting a feedback signal that includes an automatic gain control (AGC) signal and a hybrid automatic repeat request (HARQ) feedback for the data signal; and / or circuitry 1330 for receiving an indication in the SCI that HARQ feedback is enabled for the data signal.

[0142] The apparatus for transmission (or the apparatus for output for transmission) may include an antenna (e.g., antennas 252a - 252r), a transceiver (e.g., transceivers 254a - 254r), a processor (e.g., controller / processor 280), and / or circuitry for reception (e.g., circuitry for transmission 1224, 1230, 1328). The apparatus for reception (or the apparatus for acquisition) may include an antenna (e.g., antennas 252a - 252r), a transceiver (e.g., transceivers 254a - 254r), a processor (e.g., controller / processor 280), and / or circuitry for reception (e.g., circuitry for reception 1228, 1324, 1330). The apparatus for suppressing transmission may include a transceiver (e.g., transceivers 254a - 254r), a processor (e.g., controller / processor 280), and / or circuitry for suppression (e.g., circuitry for suppression 1226, 1326). The apparatus for adjustment may include a transceiver (e.g., transceivers 254a - 254r), a processor (e.g., controller / processor 280), and / or circuitry for adjustment (e.g., circuitry for adjustment 1232). In various aspects, each processor and / or each circuitry may include circuitry, a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or a combination thereof, designed to perform the functions described herein.

[0143] Example aspects

[0144] In addition to the aspects described above, aspects of specific combinations are also within the scope of the present disclosure, some of which are described in detail below:

[0145] Aspect 1: A method for wireless communication, comprising: transmitting a data signal; suppressing transmission during a gap portion that occurs in time after transmitting the data signal, wherein the gap portion has a duration less than or equal to a value; and receiving a feedback signal after the gap portion, wherein the feedback signal includes at least an automatic gain control (AGC) signal and a hybrid automatic repeat request (HARQ) feedback for the data signal.

[0146] Aspect 2: The method of aspect 1, further comprising: transmitting an indication in side - link control information (SCI) that HARQ feedback is enabled for the data signal.

[0147] Aspect 3: The method of aspect 2, wherein the SCI further indicates a symbol during which the data signal ends, and the method further comprises: determining another symbol for receiving the feedback signal based on the symbol.

[0148] Aspect 4: A method as in any one of Aspects 1-3, wherein the value is one of the following: fixed or configured from a set of candidate values.

[0149] Aspect 5: A method as in any one of Aspects 1-4, wherein the feedback signal is received over at least 3 symbols including a first symbol in time, a second symbol in time, and a third symbol in time, wherein the gap portion occurs during the first symbol, the AGC signal is received during the first and second symbols, and the HARQ feedback is received during the third symbol.

[0150] Aspect 6: A method as in any one of Aspects 1-4, wherein the feedback signal is received over at least 2 symbols including a first symbol in time and a second symbol in time, wherein the gap portion occurs during the first symbol, the AGC signal is received during the first symbol, and the HARQ feedback is received during the second symbol.

[0151] Aspect 7: A method as in any one of Aspects 1-4, wherein the feedback signal is received over a plurality of symbols including one or more first symbols in time and one or more second symbols in time, wherein the gap portion occurs during one of the one or more first symbols, the AGC signal is received during the one or more first symbols, and the HARQ feedback is received during the one or more second symbols.

[0152] Aspect 8: A method for wireless communication, comprising: receiving a data signal; suppressing transmission during a gap portion occurring in time after receiving the data signal, wherein the gap portion has a duration less than or equal to a value; and transmitting a feedback signal that includes an automatic gain control (AGC) signal and a hybrid automatic repeat request (HARQ) feedback for the data signal.

[0153] Aspect 9: The method of Aspect 8, further comprising: receiving an indication in side link control information (SCI) that HARQ feedback is enabled for the data signal.

[0154] Aspect 10: The method of Aspect 9, wherein the SCI further indicates a symbol during which the data signal ends, and the method further comprises: determining another symbol for transmitting the feedback signal based on the symbol.

[0155] Aspect 11: A method as in any one of Aspects 8-10, wherein the value is one of the following: fixed or configured from a set of candidate values.

[0156] Aspect 12: A method as in any of Aspects 8 - 11, wherein the feedback signal is transmitted over at least 3 symbols including a first symbol in time, a second symbol in time, and a third symbol in time, wherein the gap portion occurs during the first symbol, the AGC signal is transmitted during the first and second symbols, and the HARQ feedback is transmitted during the third symbol.

[0157] Aspect 13: A method as in any of Aspects 8 - 11, wherein the feedback signal is transmitted over at least 2 symbols including a first symbol in time and a second symbol in time, wherein the gap portion occurs during the first symbol, the AGC signal is transmitted during the first symbol, and the HARQ feedback is transmitted during the second symbol.

[0158] Aspect 14: A method as in any of Aspects 8 - 11, wherein the feedback signal is transmitted over a plurality of symbols including one or more first symbols in time and one or more second symbols in time, wherein the gap portion occurs during one of the one or more first symbols, the AGC signal is transmitted during the one or more first symbols, and the HARQ feedback is transmitted during the one or more second symbols.

[0159] Aspect 15: A method as in any of Aspects 8 - 14, wherein the AGC signal includes a low peak - to - average power ratio (low - PAPR) sequence.

[0160] Aspect 16: An apparatus for wireless communication, comprising means for performing a method as in any of Aspects 1 - 15 or 35 - 48.

[0161] Aspect 17: An apparatus for wireless communication, comprising: a memory; and a processor coupled to the memory, the memory and the processor being configured to perform a method as in any of Aspects 1 - 15 or 35 - 48.

[0162] Aspect 18: A computer - readable medium, the medium including instructions that, when executed by a processing system, cause the processing system to perform a method as in any of Aspects 1 - 15 or 35 - 48.

[0163] Aspect 19: An apparatus for wireless communication, comprising: a memory; and a processor coupled to the memory, the processor and the memory being configured to: transmit a data signal, and inhibit transmission during a gap portion that occurs in time after transmitting the data signal, wherein the gap portion has a time duration less than or equal to a threshold, receive a feedback signal after the gap portion, wherein the feedback signal includes at least one signal and a hybrid automatic repeat request (HARQ) feedback for the data signal, receive another signal, and adjust a gain applied to the another signal based on the signal.

[0164] Aspect 20: The apparatus of aspect 19, wherein the processor and the memory are further configured to: convey an indication that HARQ feedback is enabled for the data signal in side link control information (SCI).

[0165] Aspect 21: The apparatus of aspect 20, wherein: the SCI further indicates the time duration of the data signal; and the processor and the memory are configured to: initiate suppression of transmission at a time based on the time duration of the data signal.

[0166] Aspect 22: The apparatus according to any one of aspects 19 - 21, wherein the threshold is one of: fixed or configured from a set of candidate values.

[0167] Aspect 23: The apparatus according to any one of aspects 19 - 22, wherein the processor and the memory are configured to: receive the feedback signal on at least 3 symbols including a first symbol in time, a second symbol in time, and a third symbol in time, wherein the gap portion occurs during the first symbol, and the signal is received during the first and second symbols, and the HARQ feedback is received during the third symbol.

[0168] Aspect 24: The apparatus according to any one of aspects 19 - 22, wherein the processor and the memory are configured to: receive the feedback signal on at least 2 symbols including a first symbol in time and a second symbol in time, wherein the gap portion occurs during the first symbol, and the signal is received during the first symbol, and the HARQ feedback is received during the second symbol.

[0169] Aspect 25: The apparatus according to any one of aspects 19 - 22, wherein the processor and the memory are configured to: receive the feedback signal on a plurality of symbols including a first one or more symbols in time and a second one or more symbols in time, wherein the gap portion occurs during one of the first one or more symbols, and the signal is received during the first one or more symbols, and the HARQ feedback is received during the second one or more symbols.

[0170] Aspect 26: The apparatus according to any one of aspects 19 - 25, wherein the processor and the memory are configured to: transmit a portion of the data signal in a time slot, and suppress transmission during the gap portion in the time slot; and receive the feedback signal in the time slot.

[0171] Aspect 27: A device for wireless communication, comprising: a memory; a processor coupled to the memory, the processor and the memory being configured to: receive an indication in side link control information (SCI) that hybrid automatic repeat request (HARQ) feedback is enabled for a data signal, receive the data signal, inhibit transmission during a gap portion that occurs in time after the data signal is received, wherein the gap portion has a time duration less than or equal to a threshold, and transmit a feedback signal after the gap portion, the feedback signal including a signal and HARQ feedback for the data signal.

[0172] Aspect 28: The device of aspect 27, wherein: the SCI further indicates the time duration of the data signal; and the processor and the memory are configured to: initiate inhibiting transmission at a time based on the time duration of the data signal.

[0173] Aspect 29: The device according to any one of aspects 27 or 28, wherein the threshold is one of: fixed or configured from a set of candidate values.

[0174] Aspect 30: The device according to any one of aspects 27-29, wherein the processor and the memory are configured to: transmit the feedback signal on at least 3 symbols including a first symbol in time, a second symbol in time, and a third symbol in time, wherein the gap portion occurs during the first symbol, and wherein the processor and the memory are configured to transmit the signal during the first and second symbols, and transmit the HARQ feedback during the third symbol.

[0175] Aspect 31: The device according to any one of aspects 27-29, wherein the processor and the memory are configured to: transmit the feedback signal on at least 2 symbols including a first symbol in time and a second symbol in time, wherein the gap portion occurs during the first symbol, and wherein the processor and the memory are configured to transmit the signal during the first symbol and transmit the HARQ feedback during the second symbol.

[0176] Aspect 32: The device of aspect 27, wherein the processor and the memory are configured to: transmit the feedback signal on a plurality of symbols including a first one or more symbols in time and a second one or more symbols in time, wherein the gap portion occurs during one of the first one or more symbols, and wherein the processor and the memory are configured to transmit the signal during the first one or more symbols and transmit the HARQ feedback during the second one or more symbols.

[0177] Aspect 33: The device of aspect 27, wherein the signal includes a low peak-to-average power ratio (low-PAPR) sequence.

[0178] Aspect 34: The apparatus of aspect 27, wherein: the processor and the memory are configured to: receive a portion of the data signal in a time slot and inhibit transmission during the gap portion of the time slot and transmit the feedback signal in the time slot; and the signal is an automatic gain control (AGC) signal.

[0179] Aspect 35: A method for wireless communication, comprising: transmitting a data signal; inhibiting transmission during a gap portion that occurs in time after transmitting the data signal, wherein the gap portion has a duration less than or equal to a threshold; receiving a feedback signal after the gap portion, wherein the feedback signal includes at least one signal and a hybrid automatic repeat request (HARQ) feedback for the data signal; receiving another signal; adjusting a gain applied to the another signal based on the signal.

[0180] Aspect 36: The method of aspect 35, further comprising: transmitting an indication in side link control information (SCI) that HARQ feedback is enabled for the data signal.

[0181] Aspect 37: The method of aspect 36, wherein: the SCI further indicates the duration of the data signal, and inhibiting transmission includes initiating inhibiting transmission based on the duration of the data signal.

[0182] Aspect 38: The method according to any one of aspects 35-37, wherein the threshold is one of: fixed or configured from a set of candidate values.

[0183] Aspect 39: The method according to any one of aspects 35-38, wherein receiving the feedback signal includes receiving the feedback signal on at least 3 symbols including a first symbol in time, a second symbol in time, and a third symbol in time, wherein the gap portion occurs during the first symbol; and receiving the feedback signal further includes receiving the signal during the first and second symbols and receiving the HARQ feedback during the third symbol.

[0184] Aspect 40: The method according to any one of aspects 35-38, wherein receiving the feedback signal includes receiving the feedback signal on at least 2 symbols including a first symbol in time and a second symbol in time, wherein the gap portion occurs during the first symbol; and receiving the feedback signal further includes receiving the signal during the first symbol and receiving the HARQ feedback during the second symbol.

[0185] Aspect 41: The method according to any one of aspects 35-38, wherein receiving the feedback signal includes receiving the feedback signal on a plurality of symbols including a first one or more symbols in time and a second one or more symbols in time, wherein the gap portion occurs during one of the first one or more symbols, receiving the feedback signal further includes receiving the signal during the first one or more symbols, and receiving the HARQ feedback during the second one or more symbols.

[0186] Aspect 42: A method for wireless communication, comprising: receiving an indication in side link control information (SCI) that hybrid automatic repeat request (HARQ) feedback is enabled for a data signal; receiving the data signal; suppressing transmission during a gap portion occurring in time after receiving the data signal, wherein the gap portion has a duration less than or equal to a threshold; and transmitting a feedback signal, the feedback signal including a signal and HARQ feedback for the data signal.

[0187] Aspect 43: The method according to aspect 42, wherein: the SCI further indicates the symbol in which the data signal ends, and the method further includes transmitting the feedback signal in at least another symbol after the symbol.

[0188] Aspect 44: The method according to any one of aspects 42 or 43, wherein the threshold is one of: fixed or configured from a set of candidate values.

[0189] Aspect 45: The method according to any one of aspects 42-44, wherein transmitting the feedback signal includes transmitting the feedback signal on at least 3 symbols including a first symbol in time, a second symbol in time, and a third symbol in time, wherein the gap portion occurs during the first symbol; and transmitting the feedback signal further includes transmitting the signal during the first and second symbols, and transmitting the HARQ feedback during the third symbol.

[0190] Aspect 46: The method according to any one of aspects 42-44, wherein transmitting the feedback signal includes transmitting the feedback signal on at least 2 symbols including a first symbol in time and a second symbol in time, wherein the gap portion occurs during the first symbol; and transmitting the feedback signal further includes transmitting the signal during the first symbol, and transmitting the HARQ feedback during the second symbol.

[0191] Aspect 47: The method according to any one of aspects 42 - 44, wherein transmitting the feedback signal includes transmitting the feedback signal on a plurality of symbols including a first one or more symbols in time and a second one or more symbols in time, wherein the gap portion occurs during one of the first one or more symbols; and transmitting the feedback signal further includes transmitting the signal during the first one or more symbols and transmitting the HARQ feedback during the second one or more symbols.

[0192] Aspect 48: The method according to any one of aspects 42 - 47, wherein the signal includes a low peak-to-average power ratio (low-PAPR) sequence.

[0193] Additional Considerations

[0194] The techniques described herein can be used in various wireless communication technologies such as NR (e.g., 5G NR), 3GPP Long Term Evolution (LTE), LTE-Advanced (LTE-A), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-Carrier Frequency Division Multiple Access (SC-FDMA), Time Division-Synchronous Code Division Multiple Access (TD-SCDMA), and other networks. The terms "network" and "system" are often used interchangeably. CDMA networks can implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers the IS-2000, IS-95, and IS-856 standards. TDMA networks can implement radio technologies such as Global System for Mobile Communications (GSM). OFDMA networks can implement radio technologies such as NR (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). LTE and LTE-A are UMTS versions that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named "Third Generation Partnership Project" (3GPP). cdma2000 and UMB are described in documents from an organization named "Third Generation Partnership Project 2" (3GPP2). NR is an emerging wireless communication technology under development.

[0195] In 3GPP, the term "cell" may refer to the coverage area of a Node B (NB) and / or the NB subsystem serving that coverage area, depending on the context in which the term is used. In an NR system, the terms "cell" and BS, next-generation Node B (gNB or g B node), access point (AP), distributed unit (DU), carrier, or transmission reception point (TRP) may be used interchangeably. A BS may provide communication coverage for macro cells, picocells, femtocells, and / or other types of cells. A macro cell may cover a relatively large geographical area (e.g., with a radius of several kilometers) and may allow unconstrained access by UEs with a service subscription. A picocell may cover a relatively small geographical area and may allow unconstrained access by UEs with a service subscription. A femtocell may cover a relatively small geographical area (e.g., a residence) and may allow constrained access by UEs associated with that femtocell (e.g., UEs in a closed subscriber group (CSG), UEs of users in a residence, etc.). The BS for a macro cell may be referred to as a macro BS. The BS for a picocell may be referred to as a pico BS. The BS for a femtocell may be referred to as a femto BS or a home BS.

[0196] A UE may also be referred to as a mobile station, terminal, access terminal, subscriber unit, station, customer premise equipment (CPE), cellular phone, smartphone, personal digital assistant (PDA), wireless modem, wireless communication device, handheld device, laptop computer, cordless phone, wireless local loop (WLL) station, tablet computer, camera, gaming device, netbook, smartbook, ultrabook, appliance, medical device or equipment, biometric sensor / device, wearable device (such as a smartwatch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet, etc.)), entertainment device (e.g., music device, video device, satellite radio, etc.), vehicle component or sensor, smart meter / sensor, industrial manufacturing equipment, global positioning system device, or any other suitable device configured to communicate via wireless or wired media. Some UEs may be considered machine type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which may communicate with a BS, another device (e.g., a remote device), or some other entity. A wireless node may provide connectivity to a network (e.g., a wide area network such as the Internet or a cellular network) or provide connectivity to the network, for example, via a wired or wireless communication link. Some UEs may be considered Internet of Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

[0197] In some examples, access to the air interface can be scheduled. A scheduling entity (e.g., a BS) allocates resources for communication among some or all of the devices and equipment within its service area or cell. The scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for the scheduled communication, the subordinate entities utilize the resources allocated by the scheduling entity. A base station is not the only entity that can be used as a scheduling entity. In some examples, a UE can act as a scheduling entity and can schedule resources for one or more subordinate entities (e.g., one or more other UEs), and the other UEs can utilize the resources scheduled by the UE for wireless communication. In some examples, a UE can act as a scheduling entity in a peer-to-peer (P2P) network and / or in a mesh network. In a mesh network example, UEs can communicate directly with each other in addition to communicating with the scheduling entity.

[0198] The various methods disclosed herein include one or more steps or acts for implementing the method. These method steps and / or acts can be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of the steps or acts is specified, the order and / or use of the specific steps and / or acts can be altered without departing from the scope of the claims.

[0199] As used herein, the phrase reciting "at least one of" a list of items refers to any combination of those items, including a single member. As an example, "at least one of a, b, or c" is intended to cover: a, b, c, a - b, a - c, b - c, and a - b - c, as well as any combination with multiple identical elements (e.g., a - a, a - a - a, a - a - b, a - a - c, a - b - b, a - c - c, b - b, b - b - b, b - b - c, c - c, and c - c - c, or any other ordering of a, b, and c).

[0200] As used herein, the term "determine" encompasses a variety of actions. For example, "determine" can include computing, calculating, processing, deriving, researching, looking up (e.g., looking up in a table, database, or another data structure), ascertaining, and the like. Moreover, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Moreover, "determine" can include parsing, selecting, choosing, establishing, and the like.

[0201] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, wherein the recitation of a singular element is not intended to mean "one and only one" (unless specifically so stated) but rather "one or more." The term "some," unless specifically stated otherwise, means one or more. Elements of the various aspects described throughout this disclosure that are presently known or later come to be known to those of ordinary skill in the art as structural and functional equivalents are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public, whether or not such disclosure is explicitly recited in the claims. No element of a claim should be construed under the provisions of 35 U.S.C. § 112(f) unless the element is expressly recited using the phrase "means for" or, in the case of a method claim, the element is recited using the phrase "step for."

[0202] The various operations of the methods described above can be performed by any suitable means capable of performing the corresponding functions. These means may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs), or processors. In general, where there are operations illustrated in the figures, these operations may have corresponding paired means-plus-function components with similar numbers.

[0203] The various illustrative logical blocks, modules, and circuits described in connection with the present disclosure can be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), 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 commercially available 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.

[0204] If implemented in hardware, an example hardware configuration may include a processing system in a wireless node. The processing system can be implemented with a bus architecture. Depending on the specific application and overall design constraints of the processing system, the bus may include any number of interconnecting buses and bridges. The bus can link together various circuits including a processor, a machine-readable medium, and a bus interface. The bus interface can be used to connect, via the bus, a network adapter and the like to the processing system. The network adapter can be used to implement the signal processing functions of the PHY layer. In the case of a user terminal (see Figure 1 ), a user interface (such as a keypad, a display, a mouse, a joystick, etc.) can also be connected to the bus. The bus can also link various other circuits, such as a timing source, peripherals, voltage regulators, power management circuits, and similar circuits, which are well known in the art and thus will not be described further. The processor can be implemented with one or more general-purpose and / or special-purpose processors. Examples include a microprocessor, a microcontroller, a DSP processor, and other circuitry capable of executing software. Depending on the specific application and overall design constraints imposed on the overall network or system, those skilled in the art will recognize how best to implement the functionality described with respect to the processing system.

[0205] If implemented in software, the functions can be stored on or transmitted via a computer-readable medium as one or more instructions or code. Software should be construed broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The computer-readable medium includes both computer storage media and communication media, which include any medium that facilitates the transfer of a computer program from one place to another. The processor can be responsible for managing the bus and general processing, including executing software modules stored on the machine-readable storage medium. The computer-readable storage medium can be coupled to the processor such that the processor can read from and write to the storage medium. In an alternative, the storage medium can be integrated into the processor. As an example, the machine-readable medium can include a transmission line, a carrier modulated by data, and / or a computer-readable storage medium separate from the wireless node on which instructions are stored, all of which can be accessed by the processor via the bus interface. Alternatively or additionally, the machine-readable medium or any part thereof can be integrated into the processor, such as may be the case with a cache and / or a general register file. As an example, examples of the machine-readable medium can include RAM (Random Access Memory), flash memory, ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), registers, magnetic disks, optical disks, hard drives, or any other suitable storage medium, or any combination thereof. The machine-readable medium can be embodied in a computer program product.

[0206] A software module can include a single instruction or many instructions and can be distributed over several different code segments, distributed among different programs, and distributed across multiple storage media. A computer-readable medium can include multiple software modules. These software modules include instructions that, when executed by an apparatus such as a processor, cause the processing system to perform various functions. These software modules can include a transmission module and a reception module. Each software module can reside in a single storage device or be distributed across multiple storage devices. As an example, when a triggering event occurs, a software module can be loaded from a hard drive into RAM. During execution of the software module, the processor can load some instructions into a cache to increase access speed. One or more cache lines can then be loaded into the general register file for execution by the processor. When referring to the functionality of a software module below, it will be understood that such functionality is implemented by the processor when the processor executes instructions from the software module.

[0207] Similarly, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a web site, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology such as infrared (IR), radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology such as infrared, radio, and microwave is included in the definition of the medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and disc, where disk often magnetically reproduces data, while disc optically reproduces data with a laser. Thus, in some aspects, a computer-readable medium can include a non-transitory computer-readable medium (e.g., a tangible medium). Additionally, for other aspects, a computer-readable medium can include a transitory computer-readable medium (e.g., a signal). Combinations of the above should also be included within the scope of computer-readable media.

[0208] Accordingly, certain aspects can include a computer program product for performing the operations given herein. For example, such a computer program product can include a computer-readable medium having (and / or encoded with) instructions that can be executed by one or more processors to perform the operations described herein, such as instructions for performing the operations described and illustrated in Figure 10 and / or Figure 11 herein.

[0209] In addition, it should be appreciated that modules and / or other suitable means for performing the methods and techniques described herein can be downloaded and / or otherwise obtained by a user terminal and / or a base station, where applicable. For example, such devices can be coupled to a server to facilitate the transfer of means for performing the methods described herein. Alternatively, the various methods described herein can be provided via a storage device (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or a floppy disk, etc.) such that once the storage device is coupled to or provided to the user terminal and / or the base station, the device can obtain the various methods. In addition, any other suitable technique for providing the methods and techniques described herein to a device can be utilized.

[0210] It will be understood that the claims are not limited to the exact configurations and components described above. Various changes, substitutions, and modifications can be made in the layout, operation, and details of the methods and apparatuses described above without departing from the scope of the claims.

Claims

1. An apparatus for wireless communication, comprising: one or more memories; and one or more processors, the one or more processors being coupled to the one or more memories and configured to: transmit an indication in side - link control information (SCI) that hybrid automatic repeat request (HARQ) feedback is enabled for a data signal; transmit the data signal, and suppress transmission during a gap portion that occurs in time after transmitting the data signal, wherein the gap portion has a duration less than or equal to a threshold; receive a feedback signal after the gap portion, wherein the feedback signal includes at least an automatic gain control (AGC) signal and HARQ feedback for the data signal; receive another signal, and adjust a gain applied to the another signal based on the AGC signal.

2. The apparatus according to claim 1, wherein: the SCI further indicates a time duration of the data signal; and the one or more processors are configured to initiate suppression of transmission at a time based on the duration of the data signal.

3. The apparatus according to claim 1, wherein the threshold is one of: fixed or configured from a set of candidate values.

4. The apparatus according to claim 1, wherein the one or more processors are configured to: receive the feedback signal on at least 3 symbols including a first symbol in time, a second symbol in time, and a third symbol in time, wherein the gap portion occurs during the first symbol, and receive the signal during the first symbol and the second symbol, and receive the HARQ feedback during the third symbol.

5. The apparatus according to claim 1, wherein the one or more processors are configured to: receive the feedback signal on at least 2 symbols including a first symbol in time and a second symbol in time, wherein the gap portion occurs during the first symbol, and receive the signal during the first symbol and receive the HARQ feedback during the second symbol.

6. The apparatus according to claim 1, wherein the one or more processors are configured to: receive the feedback signal on a plurality of symbols including a first one or more symbols in time and a second one or more symbols in time, wherein the gap portion occurs during one of the first one or more symbols, and receive the signal during the first one or more symbols and receive the HARQ feedback during the second one or more symbols.

7. The apparatus according to claim 1, wherein the one or more processors are configured to: transmit at least a portion of the data signal in a time slot and suppress transmission during the gap portion in the time slot; and receive the feedback signal in the time slot.

8. An apparatus for wireless communication, comprising: one or more memories; and one or more processors, the one or more processors being coupled to the one or more memories and configured to: receive an indication in side - link control information (SCI) that hybrid automatic repeat request (HARQ) feedback is enabled for a data signal, receive the data signal, Suppress transmission during a gap portion that occurs in time after receiving the data signal, where the gap portion has a duration less than or equal to a threshold, and Transmit a feedback signal that includes at least an automatic gain control (AGC) signal and HARQ feedback for the data signal.

9. The apparatus of claim 8, wherein: the SCI further indicates the time duration of the data signal; and the one or more processors are configured to initiate suppression of transmission at a time based on the duration of the data signal.

10. The apparatus of claim 8, wherein the threshold is one of: fixed or configured from a set of candidate values.

11. The apparatus of claim 8, wherein the one or more processors are configured to: transmit the feedback signal on at least 3 symbols including a first symbol in time, a second symbol in time, and a third symbol in time, where the gap portion occurs during the first symbol, and wherein the one or more processors are configured to: transmit the signal during the first and second symbols, and transmit the HARQ feedback during the third symbol.

12. The apparatus of claim 8, wherein the one or more processors are configured to: transmit the feedback signal on at least 2 symbols including a first symbol in time and a second symbol in time, where the gap portion occurs during the first symbol, and wherein the one or more processors are configured to: transmit the signal during the first symbol, and transmit the HARQ feedback during the second symbol.

13. The apparatus of claim 8, wherein the one or more processors are configured to: transmit the feedback signal on a plurality of symbols including a first one or more symbols in time and a second one or more symbols in time, where the gap portion occurs during one of the first one or more symbols, and wherein the one or more processors are configured to: transmit the signal during the first one or more symbols, and transmit the HARQ feedback during the second one or more symbols.

14. The apparatus of claim 8, wherein the signal includes a low peak-to-average power ratio (low-PAPR) sequence.

15. The apparatus of claim 8, wherein: the one or more processors are configured to receive a portion of the data signal in a time slot, and suppress transmission and transmit the feedback signal in the gap portion of the time slot.

16. A method for wireless communication, comprising: Transmitting an indication in side link control information (SCI) that hybrid automatic repeat request (HARQ) feedback is enabled for a data signal; Transmitting the data signal; Suppressing transmission during a gap portion that occurs in time after transmitting the data signal, where the gap portion has a duration less than or equal to a threshold; Receiving a feedback signal after the gap portion, where the feedback signal includes at least an automatic gain control (AGC) signal and HARQ feedback for the data signal; Receiving another signal; and Adjust the gain applied to the other signal based on the AGC signal.

17. The method according to claim 16, wherein: the SCI further indicates the duration of the data signal; and initiate suppression of transmission including based on the duration of the data signal.

18. The method according to claim 16, wherein the threshold is one of: fixed or configured from a set of candidate values.

19. The method according to claim 16, wherein: receiving the feedback signal includes receiving the feedback signal on at least 3 symbols including a first symbol in time, a second symbol in time, and a third symbol in time, wherein the gap portion occurs during the first symbol; and receiving the feedback signal further includes receiving the signal during the first symbol and the second symbol, and receiving the HARQ feedback during the third symbol.

20. The method according to claim 16, wherein: receiving the feedback signal includes receiving the feedback signal on at least 2 symbols including a first symbol in time and a second symbol in time, wherein the gap portion occurs during the first symbol, receiving the feedback signal further includes receiving the signal during the first symbol and receiving the HARQ feedback during the second symbol.

21. The method according to claim 16, wherein: receiving the feedback signal includes receiving the feedback signal on a plurality of symbols including one or more first symbols in time and one or more second symbols in time, wherein the gap portion occurs during one of the one or more first symbols, receiving the feedback signal further includes receiving the signal during the one or more first symbols and receiving the HARQ feedback during the one or more second symbols.

22. A method for wireless communication, comprising: receiving an indication in side - link control information SCI that hybrid automatic repeat request HARQ feedback is enabled for a data signal; receiving the data signal; suppressing transmission during a gap portion that occurs in time after receiving the data signal, wherein the gap portion has a duration less than or equal to a threshold; and transmitting a feedback signal that at least includes an automatic gain control AGC signal and HARQ feedback for the data signal.

23. The method according to claim 22, wherein: the SCI further indicates the symbol in which the data signal ends, and the method further includes transmitting the feedback signal in at least another symbol after the symbol.

24. The method according to claim 22, wherein the threshold is one of: fixed or configured from a set of candidate values.

25. The method according to claim 22, wherein: transmitting the feedback signal includes transmitting the feedback signal on at least 3 symbols including a first symbol in time, a second symbol in time, and a third symbol in time, wherein the gap portion occurs during the first symbol; and Transmitting the feedback signal further includes transmitting the signal during the first symbol and the second symbol, and transmitting the HARQ feedback during the third symbol.

26. The method according to claim 22, wherein: transmitting the feedback signal includes transmitting the feedback signal on at least two symbols including a first symbol in time and a second symbol in time, wherein the gap portion occurs during the first symbol; and transmitting the feedback signal further includes transmitting the signal during the first symbol and transmitting the HARQ feedback during the second symbol.

27. The method according to claim 22, wherein: transmitting the feedback signal includes transmitting the feedback signal on a plurality of symbols including a first one or more symbols in time and a second one or more symbols in time, wherein the gap portion occurs during one of the first one or more symbols; and transmitting the feedback signal further includes transmitting the signal during the first one or more symbols and transmitting the HARQ feedback during the second one or more symbols.

28. The method according to claim 22, wherein the signal includes a low peak-to-average power ratio (low-PAPR) sequence.

29. An apparatus for wireless communication, comprising: means for transmitting an indication in side link control information SCI that hybrid automatic repeat request HARQ feedback is enabled for a data signal; means for transmitting the data signal, means for suppressing transmission during a gap portion that occurs in time after transmitting the data signal, wherein the gap portion has a duration less than or equal to a threshold, means for receiving a feedback signal after the gap portion, wherein the feedback signal includes at least an automatic gain control AGC signal and HARQ feedback for the data signal, means for receiving another signal, and means for adjusting a gain applied to the another signal based on the AGC signal.

30. The apparatus according to claim 29, wherein: the SCI further indicates the duration of the data signal; and the means for suppressing transmission includes means for initiating suppression of transmission based on the duration of the data signal.

31. The apparatus according to claim 29, wherein the threshold is one of: fixed or configured from a set of candidate values.

32. The apparatus according to claim 29, wherein the means for receiving the feedback signal comprises: means for receiving the feedback signal on at least three symbols including a first symbol in time, a second symbol in time, and a third symbol in time, wherein the gap portion occurs during the first symbol, means for receiving the signal during the first symbol and the second symbol, and means for receiving the HARQ feedback during the third symbol.

33. The apparatus according to claim 29, wherein the means for receiving the feedback signal comprises: for receiving the feedback signal on at least two symbols including a first symbol in time and a second symbol in time, wherein the gap portion occurs during the first symbol, means for receiving the signal during the first symbol, and means for receiving the HARQ feedback during the second symbol.

34. The apparatus according to claim 29, wherein the means for receiving the feedback signal: means for receiving the feedback signal on a plurality of symbols including a first one or more symbols in time and a second one or more symbols in time, wherein the gap portion occurs during one of the first one or more symbols, means for receiving the signal during the first one or more symbols, and means for receiving the HARQ feedback during the second one or more symbols.

35. The apparatus according to claim 29, wherein: the means for transmitting the data signal includes means for transmitting at least a portion of the data signal in a time slot, the means for suppressing transmission during a gap portion occurring in time after transmitting the data signal includes means for suppressing transmission during the gap portion in the time slot, and the means for receiving a feedback signal after the gap portion includes means for receiving the feedback signal in the time slot.

36. An apparatus for wireless communication, comprising: means for receiving an indication in side link control information SCI that hybrid automatic repeat request HARQ feedback is enabled for a data signal, means for receiving the data signal, means for suppressing transmission during a gap portion occurring in time after receiving the data signal, wherein the gap portion has a duration less than or equal to a threshold, and means for transmitting a feedback signal, the feedback signal including at least an automatic gain control AGC signal and HARQ feedback for the data signal.

37. The apparatus according to claim 36, wherein: the SCI further indicates the time duration of the data signal; and the apparatus includes means for initiating suppression of transmission at a time based on the duration of the data signal.

38. The apparatus according to claim 36, wherein the threshold is one of: fixed or configured from a set of candidate values.

39. The apparatus according to claim 36, wherein the means for transmitting the feedback signal comprises: means for transmitting the feedback signal on at least three symbols including a first symbol in time, a second symbol in time, and a third symbol in time, wherein the gap portion occurs during the first symbol, means for transmitting the signal during the first and second symbols, and means for transmitting the HARQ feedback during the third symbol.

40. The apparatus according to claim 36, wherein the means for transmitting the feedback signal: means for transmitting the feedback signal on at least two symbols including a first symbol in time and a second symbol in time, wherein the gap portion occurs during the first symbol, Apparatus for transmitting the signal during the first symbol, and Apparatus for transmitting the HARQ feedback during the second symbol.

41. The apparatus according to claim 36, wherein the apparatus for transmitting the feedback signal comprises: Apparatus for transmitting the feedback signal over a plurality of symbols including one or more first symbols in time and one or more second symbols in time, wherein the gap portion occurs during one of the one or more first symbols, Apparatus for transmitting the signal during the one or more first symbols, and Apparatus for transmitting the HARQ feedback during the one or more second symbols.

42. The apparatus according to claim 36, wherein the signal comprises a low peak-to-average power ratio (low-PAPR) sequence.

43. The apparatus according to claim 36, wherein: The apparatus for receiving the data signal comprises apparatus for receiving a portion of the data signal in a time slot, The apparatus for suppressing transmission during a gap portion occurring in time after receiving the data signal comprises apparatus for suppressing transmission during the gap portion in the time slot, and The apparatus for transmitting the feedback signal comprises apparatus for transmitting the feedback signal in the time slot.

44. A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by at least one processor for: Transmitting an indication in side link control information SCI that hybrid automatic repeat request HARQ feedback is enabled for a data signal; Transmitting the data signal, and Suppressing transmission during a gap portion occurring in time after transmitting the data signal, wherein the gap portion has a duration less than or equal to a threshold, Receiving a feedback signal after the gap portion, wherein the feedback signal comprises at least an automatic gain control AGC signal and HARQ feedback for the data signal, Receiving another signal, and Adjusting the gain applied to the another signal based on the AGC signal.

45. The non-transitory computer-readable medium according to claim 44, wherein: The SCI further indicates the time duration of the data signal; and The instructions are further executable by the at least one processor to initiate suppression of transmission based on the time of the duration of the data signal.

46. The non-transitory computer-readable medium according to claim 44, wherein the threshold is one of: fixed or configured from a set of candidate values.

47. The non-transitory computer-readable medium according to claim 44, wherein the instructions are further executable by the at least one processor to: Receive the feedback signal over at least 3 symbols including a first symbol in time, a second symbol in time, and a third symbol in time, wherein the gap portion occurs during the first symbol, and Receive the signal during the first and second symbols, and receive the HARQ feedback during the third symbol.

48. The non-transitory computer-readable medium of claim 44, wherein the instructions are further executable by the at least one processor to: receive the feedback signal on at least two symbols including a first symbol in time and a second symbol in time, wherein the gap portion occurs during the first symbol, and receive the signal during the first symbol and receive the HARQ feedback during the second symbol.

49. The non-transitory computer-readable medium of claim 44, wherein the instructions are further executable by the at least one processor to: receive the feedback signal on a plurality of symbols including a first one or more symbols in time and a second one or more symbols in time, wherein the gap portion occurs during one of the first one or more symbols, and receive the signal during the first one or more symbols and receive the HARQ feedback during the second one or more symbols.

50. The non-transitory computer-readable medium of claim 44, wherein the instructions are further executable by the at least one processor to: transmit at least a portion of the data signal in a time slot and inhibit transmission during the gap portion in the time slot; and receive the feedback signal in the time slot.

51. A non-transitory computer-readable medium storing code for wireless communication, the code including instructions executable by at least one processor for: receiving an indication in side link control information SCI that hybrid automatic repeat request HARQ feedback is enabled for a data signal, receiving the data signal, inhibiting transmission during a gap portion occurring in time after receiving the data signal, wherein the gap portion has a duration less than or equal to a threshold, and transmitting a feedback signal including at least an automatic gain control AGC signal and HARQ feedback for the data signal.

52. The non-transitory computer-readable medium of claim 51, wherein: the SCI further indicates the time duration of the data signal; and the instructions are further executable by the at least one processor to initiate inhibiting transmission based on the duration of the data signal.

53. The non-transitory computer-readable medium of claim 51, wherein the threshold is one of: fixed or configured from a set of candidate values.

54. The non-transitory computer-readable medium of claim 51, wherein the instructions are further executable by the at least one processor to: transmit the feedback signal on at least three symbols including a first symbol in time, a second symbol in time, and a third symbol in time, wherein the gap portion occurs during the first symbol, and wherein the one or more processors are configured to: transmit the signal during the first symbol and the second symbol and transmit the HARQ feedback during the third symbol.

55. The non-transitory computer-readable medium of claim 51, wherein the instructions are further executable by the at least one processor to: transmit the feedback signal over at least two symbols including a first symbol in time and a second symbol in time, wherein the gap portion occurs during the first symbol, and wherein the instructions are further executable by the at least one processor to: transmit the signal during the first symbol and transmit the HARQ feedback during the second symbol.

56. The non-transitory computer-readable medium of claim 51, wherein the instructions are further executable by the at least one processor to: transmit the feedback signal over a plurality of symbols including a first one or more symbols in time and a second one or more symbols in time, wherein the gap portion occurs during one of the first one or more symbols, and wherein the instructions are further executable by the at least one processor to: transmit the signal during the first one or more symbols and transmit the HARQ feedback during the second one or more symbols.

57. The non-transitory computer-readable medium of claim 51, wherein the signal includes a low peak-to-average power ratio (low-PAPR) sequence.

58. The non-transitory computer-readable medium of claim 51, wherein: the instructions are further executable by the at least one processor to receive a portion of the data signal in a time slot and inhibit transmission during the gap portion in the time slot and transmit the feedback signal in the time slot.

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