Abstract: Methods, systems, and devices for wireless communications are described. In systems supporting unlicensed downlink and licensed uplink communications, transmitter-based and/or receiver-based listen-before-talk may be implemented. In a transmitter-based scheme, a base station performs listen-before-talk on a downlink unlicensed band to monitor for signals from other base stations. In a first receiver-based scheme, a user equipment may send a clear to send signal on the licensed uplink channel or unlicensed downlink channel to assist a listen-before-talk operation at a serving base station. In a second receiver-based scheme, the user equipment monitors for downlink preamble transmissions from base stations other than a serving base station and reports detected preambles to the serving base station. The base station may schedule the user equipment based on the reported preambles.

Abstract: Methods, systems, and devices for wireless communications are described. A base station of a first network operator (OP) may determine a priority for the first OP for a transmission opportunity of a shared or unlicensed channel. The priority may be lower than a priority of a second OP for the transmission opportunity. Base station may transmit a tentative grant to a user equipment (UE) of the first OP scheduling transmissions over resources of the transmission opportunity. The transmitting device of the first OP may monitor a contention window for reservation signals communicated by devices of the second OP. Based on the monitoring and the tentative grant, the transmitting device of the first OP may perform the transmission over the resources of the shared or unlicensed channel.

Abstract: A discovery measurement timing configuration (DMTC) window reservation signal is disclosed for new radio (NR) shared spectrum (NR-SS) networks. The DMTC window is defined providing a reserved location for transmission of essential control signaling and potentially high priority traffic that may be transmitted in a prioritized manner. Access within the DMTC window may be provided with a clear channel assessment (CCA) exempt transmission (CET) option or a non-CET option. When the CET option is used, the reservation duration and period may be conveyed through the channel reservation signal. User equipments (UEs) that detect the reservation signal may re-transmit with added offset to inform neighboring base station that may not be within range of the serving base station. Base station that receive either the transmitted or re-transmitted reservation signal will refrain from communications that may interfere with the reception at the UEs.

Abstract: Various aspects related to ACK/NACK feedback for multi-TRP transmission scenarios are described. A base station, may send, to a UE, information indicating PDCCH monitoring occasions for each of a plurality of TRPs. In one aspect, the base station may send information indicating whether ACK/NACK feedback across the plurality of TRPs is allowed. The base station may send rules to the UE for performing ACK/NACK feedback bundling for providing feedback to the plurality of TRPs. The base station may also send information indicating a DAI definition for interpreting DAIs transmitted by the plurality of TRPs in corresponding PDCCH transmissions indicating whether the DAIs are independent or joint. The base station may receive a joint ACK/NACK feedback from the UE in a PUCCH based on the rules, or may receive multiple ACK/NACK feedback from the UE in a PUCCH for a first TRP independent from a second TRP.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) and a base station may communicate in an unlicensed spectrum (e.g., a shared radio frequency spectrum band). As such, the UE may determine a codebook size for transmitting hybrid access request (HARQ) acknowledgement (ACK) feedback with respect to the unlicensed spectrum. Accordingly, the UE may base the HARQ ACK codebook size on a number of HARQ processes with which the UE has been configured. Additionally or alternatively, the UE may base the HARQ ACK codebook size on a number and/or duration of downlink channel monitoring occasions indicated by the base station. In some cases, the UE may base the HARQ ACK codebook size on a combination of the techniques described herein.

Abstract: A method and a system for narrowband wireless communication is disclosed. The base station constructs a DRS comprising a first set of contiguous NPSS subframes followed by a second set of contiguous repeating NSSS subframes. The DRS may further comprise a third set of NSSS subframes followed by a fourth set of NPSS subframes. The base station may apply a cover code to symbols of the NPSS subframes. The base station transmits the NPSS/NSSS subframes as part of a DRS subframe on an anchor channel.

Abstract: Wireless communications systems and methods related to multiplexing different waveforms in wireless networks are provided. A first wireless communication device identifies a configuration for communicating a first waveform signal before a guard interval (GI)-based waveform signal, the configuration indicating a GI waveform requirement of the GI-based waveform signal. The first wireless communication device communicates, with a second wireless communication device, the first waveform signal including a plurality of first symbols carrying data, wherein a last symbol of the plurality of first symbols includes a portion without data transmission based on the GI waveform requirement.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may rate match an uplink transmission around a set of resources reserved by a base station. The base station may indicate a set of reserved resources which overlaps an uplink resource allocation to the UE. The base station may transmit an indicator of the reserved resources, and the UE may identify a location of a clear channel assessment (CCA) gap in a symbol period relative to the reserved resources. By rate matching around the reserved resources and one or more CCA gaps, the UE may transmit uplink information despite the allocated uplink resources colliding with the reserved resources.

Abstract: Beam-specific autonomous uplink (AUL) resources may be configured with an associated reference signal for beam management. For example, a base station may configure respective sets of AUL resources that are specific to one or more base station receive beams. These sets of beam-specific AUL resources may be configured to be associated (e.g., quasi co-located (QCL)) with a reference signal, such as a channel state information reference signal (CSI-RS), a synchronization signal burst (SSB), or the like. The base station may periodically transmit the reference signals that are associated with the AUL resources. A user equipment (UE), upon detecting one or more of the reference signals, may identify which set of AUL resources are available for an AUL transmission of uplink data. In such cases, the UE may select a set of AUL resources based on a signal strength of the reference signal associated with that set of AUL resources.

Abstract: A method of wireless communication may include determining a communication operation between a base station and one or more served UEs. The method may further include monitoring for radio frequency (RF) energy on a communication channel at a beginning of a listen before talk (LBT) window of a current frame in a shared spectrum shared between at least one or more opportunistic general authorized users. The method may further include transmitting an LBT trigger signal in response to detection of no RF energy above a minimum energy threshold at the beginning of the LBT window. The method may further include receiving an LBT trigger response signal from the one or more served UEs. The method may also include communicating, by the base station, with the one or more UEs during a channel occupancy time (COT) of the current frame after the LBT window.

Abstract: Methods, systems, and devices for wireless communications are described. In a wireless communications system, multiple transmission/reception points (TRPs) may perform a joint transmission to a user equipment (UE) such that the UE may rely on demodulation reference signals (DMRSs) from the TRPs for channel estimation and data demodulation to receive the joint transmission. When TRP transmissions are punctured, which may introduce reception errors at a receiving UE, one or more TRPs may transmit unique DMRSs such that each TRP transmits a DMRS that is unique to the transmitting TRP, transmit DMRSs that are unique to punctured resource elements (REs), or determine to refrain from transmitting on punctured REs. In some cases, TRPs may transmit preemption indications (PIs) to a UE, where the PIs may indicate punctured (e.g.

Abstract: Techniques providing opportunistic frequency switching for frame based equipment (FBE), such as may be configured to minimize opportunistic frequency switching delay in FBE new radio (NR) unlicensed (NR-U) networks and/or to provide frequency diversity FBE access based on offset sequences of medium sensing occasions for the carrier frequencies are disclosed. Within the FBE mode network, a base station may configure a pattern of sensing locations in each frame for each frequency transmission unit of the plurality of frequency transmission units, wherein an inter-unit delay of sensing locations between a first frequency transmission unit and a next adjacent frequency transmission unit and between a last frequency transmission unit and the first frequency transmission unit is a fixed duration.

Abstract: Methods, systems, and devices for wireless communications are described. A base station of a first network operator (OP) may determine a priority for the first OP for a transmission opportunity of a shared or unlicensed channel. The priority may be lower than a priority of a second OP for the transmission opportunity. Base station may transmit a tentative grant to a user equipment (UE) of the first OP scheduling transmissions over resources of the transmission opportunity. The transmitting device of the first OP may monitor a contention window for reservation signals communicated by devices of the second OP. Based on the monitoring and the tentative grant, the transmitting device of the first OP may perform the transmission over the resources of the shared or unlicensed channel.

Abstract: Various aspects related to ACK/NACK feedback for multi-TRP transmission scenarios are described. A base station, may send, to a UE, information indicating PDCCH monitoring occasions for each of a plurality of TRPs. In one aspect, the base station may send information indicating whether ACK/NACK feedback across the plurality of TRPs is allowed. The base station may send rules to the UE for performing ACK/NACK feedback bundling for providing feedback to the plurality of TRPs. The base station may also send information indicating a DAI definition for interpreting DAIs transmitted by the plurality of TRPs in corresponding PDCCH transmissions indicating whether the DAIs are independent or joint. The base station may receive a joint ACK/NACK feedback from the UE in a PUCCH based on the rules, or may receive multiple ACK/NACK feedback from the UE in a PUCCH for a first TRP independent from a second TRP.

Abstract: Coordination of listen before talk (LBT) structure in new radio (NR) unlicensed (NR-U) multi-channel access operations is disclosed. In one aspect, when a base station determines to access shared communication spectrum, it may transmit an LBT structure signal that identifies the current LBT structure. The base station would then attempt access to the shared spectrum according to the LBT structure. In another aspect, a coordination server is used to manage access to the shared spectrum. Each node desiring access registers with the coordination server, which provides access parameters for the accessing node to use that increases the likelihood of successful access. The accessing nodes will transmit the selected access configuration used to access the shared spectrum, wherein the access configuration is selected based on the access parameters.

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: Methods, systems, and devices for wireless communications are described that asynchronous carrier aggregation, including between high frequency band and lower frequency band transmissions. A user equipment (UE) may be configured to monitor transmissions in a first frequency band and a second frequency band. The UE may measure a timing difference between transmissions in the first frequency band and one or more of the transmissions in the second frequency band, and transmit an indication of the timing difference to a base station. The base station may use the timing difference to determine whether the UE is to use asynchronous carrier aggregation. If the base station determines that the UE is to use asynchronous carrier aggregation, the base station may configure the UE to observe at least a minimum amount of delay when conducting uplink signaling via one of the frequency bands.

Abstract: Wireless communications systems and methods related to applying variable cyclic prefix (CP) lengths to symbols within a transmission period in a wireless network are provided. A first wireless communication device identifies a first cyclic prefix (CP) configuration for a transmission period. The first wireless communication device communicates, with a second wireless communication device during the transmission period, a first communication signal including a first plurality of symbols, wherein each of the first plurality of symbols include an individually configurable CP length configured based on the first CP configuration. A first symbol of the first plurality of symbols includes a first CP length. A second symbol of the first plurality of symbols includes a second CP length that is longer than the first CP length.

Abstract: In an embodiment, an AP executes a CCA protocol to determine whether to begin transmission within a DMTC window of a radio frame having first and second blocks of subframes. The AP transmits a multi-subframe DRS within the DRS subframes that is scrambled in accordance with a CSI-RS scrambling rule that determines how the second DRS subframe is to be scrambled based on whether the first DRS subframe is included among the first block of subframes or the second block of subframes. At least one UE monitors the DMTC window, and descrambles the CSI-RSs in the multi-DRS subframe based on a CSI-RS descrambling rule that determines how the second DRS subframe is to be descrambled based on whether the first DRS subframe is included among the first block of subframes or the second block of subframes.

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.