Abstract: Techniques are described for wireless communication. An orthogonal frequency-division multiple access (OFDMA) configuration of an uplink channel is identified for communications in an unlicensed radio frequency spectrum band. An OFDMA waveform is generated based on the identified OFDMA configuration. The OFDMA waveform is communicated in a signal in the unlicensed radio frequency spectrum band. A virtual cell identifier of a first base station may be associated with transmissions between the first base station and a first user equipment (UE). A set of common resource blocks may be identified for transmission of a demodulation reference signal (DM-RS) between the first base station and the first UE. A configuration of an uplink channel may be dynamically selected for uplink communications in an unlicensed radio frequency spectrum band. A waveform may be generated based on the selected configuration. The waveform may be communicated in a signal in the unlicensed radio frequency spectrum band.

Abstract: Aspects of the present disclosure provide techniques for uplink (UL) data channel design. An example method is provided for operations which may be performed by a first apparatus. The example method generally comprises determining a number of pilot symbols to transmit for one or more slots of a first subframe based, at least in part, on a coverage enhancement (CE) level, and transmitting at least one uplink data channel having the determined number of pilot symbols in the one or more slots of the first subframe.

Abstract: Aligned listen before talk (LBT) gaps for single operator frame-based equipment (FBE) mode new radio (NR) shared spectrum (NR-SS) is disclosed. Within the FBE mode network, the base station determines a plurality of potential transmission bursts within a fixed frame period. The base station may then reserve a plurality of LBT gaps prior to the starting position of each such transmission burst. The base station communicates the location of each of the LBT gaps to all neighboring network entities and contends for access to the fixed frame period at the beginning of the frame regardless of whether it has data for transmission during the frame. Each neighboring base station that receives the LBT gaps locations will use the same locations in order to align the LBT gaps over the FBE mode network.

Abstract: Aspects of the present disclosure provide techniques for uplink (UL) data channel design. An example method is provided for operations which may be performed by a first apparatus. The example method generally comprises determining a number of pilot symbols to transmit for one or more slots of a first subframe based, at least in part, on a coverage enhancement (CE) level, and transmitting at least one uplink data channel having the determined number of pilot symbols in the one or more slots of the first subframe.

Abstract: Methods, systems, and devices for wireless communications are described. In a first case, a first user equipment (UE) may transmit to a second UE a sidelink discovery message preamble corresponding to a sidelink discovery message. The first UE may identify resources for transmission of the sidelink discovery messages based on the sidelink discovery message preamble. The first UE may either transmit the sidelink discovery message to the second UE or may receive the sidelink discovery message from the second UE using the identified resources for the transmission of the sidelink discovery message. In some cases, the second UE may transmit sidelink control information (SCI) to the first UE, and may transmit a sidelink discovery message to the first UE based on resources identified in the SCI. In some cases, the first UE may transmit the sidelink discovery message without transmission of a preamble or a SCI.

Abstract: Wireless communications systems and methods related to providing frequency diversity for communications in an unlicensed spectrum are provided. A first wireless communication device communicates, with a second wireless communication device, an opportunistic frequency-switching configuration for a first frequency band and a second frequency band. The first frequency band and the second frequency band are shared by a first network operating entity and a second network operating entity. The first wireless communication device communicates, with the second wireless communication device, a first communication signal in a first frequency band based on the opportunistic frequency-switching configuration. The first wireless communication device switches from the first frequency band to a second frequency band based on the opportunistic frequency-switching configuration.

Abstract: Methods, systems, and devices are described for providing allocations and signaling for different types of communications within a wireless communication system. An eNB and/or a UE may be configured to operate within the wireless communication system using two or more different types of communications. The different types of communications may differ, for example, based on round trip time (RTT) between transmission and acknowledgment of receipt of the transmission, a transmission time interval (TTI) for wireless transmissions, and/or duty cycle timing of wireless transmissions. Reserved resources within a system bandwidth may be identified for a first type of communications, and all or a portion of remaining resources within the system bandwidth may be allocated for other communications that may differ from the first type of communications based on, for example, RTT, TTI, and/or duty cycle timing.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment may monitor for a transmission over a set of periodically scheduled resources (e.g., semi-persistently scheduled resources)) of a downlink shared channel in an unlicensed spectrum. The user equipment may receive the transmission, where the transmission indicates a channel access configuration (e.g., a listen-before-talk configuration) for accessing the unlicensed spectrum. In some cases, the transmission may include a medium access control (MAC) control element (MAC-CE) that indicates the channel access configuration. The transmission may additionally indicate at least one uplink channel over which the user equipment may transmit a message and/or a channel occupancy time associated with a successful acquisition of the unlicensed spectrum by the base station. The user equipment may transmit a message (e.g., an acknowledgement) based on the channel access configuration.

Abstract: Methods, systems, and devices for wireless communications are described that provide for frame-based initiator device operations. A wireless device may be operating within a frame-based equipment communications system, where a frame may include a channel occupancy time period and a minimum idle period. An initiating device may be configured to initiate autonomous uplink communications during the channel occupancy time period of its frame, while the device may not initiate communications during an idle period of its frame. In some cases, a frame-based equipment communications system may include more than one initiating device, where the idle periods for different initiating devices may occur at different times. In some cases, the initiating device may be configured to initiate communications during the idle period for another initiating device. This may allow the wireless system to decrease system overhead associated with a minimum idle period per frame.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine that an availability condition is satisfied, wherein the availability condition relates to an availability of the UE for sidelink communication; identify future available information (FAI) that indicates at least one of a time domain availability of the UE for sidelink communication or a frequency domain availability of the UE for sidelink communication; and transmit the FAI based at least in part on determining that the availability condition is satisfied. Numerous other aspects are provided.

Abstract: Certain aspects of the present disclosure generally relate to wireless communications, and more specifically increasing user capacity through a frame structure which supports enhanced Machine Type Communication (eMTC) UL multi-user multiplexing. For example, a User Equipment (UE) identifies at least one narrowband region within a wider system bandwidth. The UE receives signaling, from a base station, indicating a sub-region of the narrowband region assigned to the UE for transmitting symbols of a physical uplink channel that are multiplexed with symbols transmitted by one or more other UEs in the narrowband region. The UE transmits the physical uplink channel in the assigned sub-region. Similar techniques are also provided that may be applied to DL multi-user multiplexing.

Abstract: Wireless communications systems and methods related to channel access contention management in a shared radio frequency band are provided. A first wireless communication device communicates, with a second wireless communication device, a grant for communicating a first communication signal, the grant indicating a listen-before-talk (LBT) configuration. The first wireless communication device communicates, with the second wireless communication device, a LBT configuration modification after communicating the grant. The first wireless communication device communicates, with the second wireless communication device, the first communication signal based on the LBT configuration modification.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may identify that the UE is configured to use a two-step random access channel (RACH) procedure. The two-step RACH procedure may include an uplink request message and a downlink response. The UE may transmit the uplink request message as part of the two-step RACH procedure, and the uplink request message may include a preamble portion that is one of a set of predefined sequences and a payload portion that includes a physical uplink shared channel waveform. The UE may receive the downlink response as part of the two-step RACH procedure and in response to the uplink request message.

Abstract: A base station may configure a set of autonomous uplink (AUL) resources for a specific base station receive beam, or the AUL resources may be configured for specific user equipment (UEs) or user groups. Additionally, the AUL resources may be configured to include a sensing portion, a data portion, or both. As an example, a UE may receive an AUL configuration that includes an indication of a set of AUL resources that are specific to a base station receive beam. The UE may then determine that the set of AUL resources is available and perform an AUL transmission of uplink data using the set of beam-specific AUL resources. Additionally or alternatively, the UE may perform the AUL transmission with respective portions that include a sensing signal and the uplink data. The base station may use the sensing signal to determine a receive beam on which to receive the uplink data.

Abstract: Methods, systems, and devices are described for hierarchical communications and low latency support within a wireless communications system. An eNB and/or a UE may be configured to operate within the wireless communications system which is at least partially defined through a first layer with first layer transmissions having a first subframe type and a second layer with second layer transmissions having a second subframe type. The first subframe type may have a first round trip time (RTT) between transmission and acknowledgment of receipt of the transmission, and the second layer may have a second RTT that is less than the first RTT. Subframes of the first subframe type may be multiplexed with subframes of the second subframe type, such as through time division multiplexing. In some examples symbols of different duration may be multiplexed such that different symbol durations coexist.

Abstract: Methods, systems, and devices for wireless communication are described. A wireless device (base station or UE) may receive an indication of a listen before talk (LBT) gap for sharing a channel occupancy time (COT), the COT being acquired by another wireless device (base station or UE), and detect whether a slot within the COT is occupied by the other wireless device, the slot occurring prior to the LBT gap. The wireless device may also, responsive to detecting that the slot is occupied by the other wireless device, perform an LBT procedure during the LBT gap, and, responsive to a successful LBT procedure, transmit a signal to the other wireless device within the COT.

Abstract: A method of wireless communication includes identifying, by a first node configured for operation in a synchronous communication mode, a current synchronization boundary according to a common clock of the synchronous communication mode. The method further includes performing, by the first node, a common clock-triggered (CCT) listen before talk (LBT) procedure of a shared communication channel during a periodic quiet interval at the current synchronization boundary. The method further includes establishing, by the first node, in response to success of the CCT LBT procedure, a channel occupancy time (COT) configured to end at a subsequent synchronization boundary and transmitting, by the first node, data on the shared communication channel during the COT.

Abstract: Methods, systems, and devices for wireless communication are described. A base station may determine a configuration including a set of signature waveforms for a micro-sleep mode of operation in shared spectrum, and may transmit the configuration to at least one user equipment (UE) served by the base station. Additionally, a UE may receive a configuration including a set of signature waveforms for a micro-sleep mode of operation in shared spectrum. The UE may detect at least one signature waveform of the set of signature waveforms, and in response to detecting the at least one signature waveform, operate in the micro-sleep mode for a period of time.

Abstract: Methods, systems, and devices for wireless communications are described. A base station may transmit a first downlink control information block over a group physical downlink control channel (PDCCH), wherein the first downlink control information block identifies a plurality of user equipment (UEs) for performing aperiodic channel state information (CSI) measurements and an indication of CSI reference signal resources for a CSI reference signal. The base station may transmit the CSI reference signal on the indicated CSI reference signal resources. The UE may perform, in response to receiving the group PDCCH, an aperiodic CSI measurement of the CSI reference signal on the indicated CSI reference signal resources.

Abstract: Methods and apparatuses for transmitting and detecting channel reservation preamble in a NR shared spectrum are described. An aspect may include determining whether a first reservation preamble of a first operator is received on a first time slot of multiple time slots of a downlink channel from a first network entity, and transmitting a second reservation preamble of the first operator on an uplink channel to the second network entity. Another aspect may include generating a first reservation preamble of a first operator based on at least one of a compressed representation in a signal space, a basis function of the signal space, or a CAZAC sequences; and transmitting, on a first timeslot of multiple time slots of a downlink channel, the first reservation preamble of the first operator to at least a UE.