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: Methods, systems, and devices for wireless communications are described. A base station may identify a plurality of downlink carriers for a transmission time interval (TTI), e.g., a subframe. The base station may identify a period of inactivity for one or more of the plurality of downlink carriers during the TTI, which may correspond to one or more orthogonal frequency division multiplexing (OFDM) symbols of the subframe. The base station may transmit narrowband reference signals (NB-RSs) over the one or more carriers during the period of inactivity according to a channel reservation narrowband reference signal (NB-RS) pattern. The channel reservation NB-RS pattern may include a first set of time-frequency resources associated with a baseline NB-RS pattern and a second set of supplemental time-frequency resources associated with a period of inactivity.

Abstract: Quasi-colocation (QCL) for listen before talk (LBT) procedures is disclosed. A base station having a plurality of antennas may identify one or more groups of QCL antennas. Various aspects provide for different rules defining the QCL relationship, such as base on interference experienced by the antennas, a physical or logical connection of the antennas and LBT coupling, or synchronization. QCL may further be determined across multiple shared channels, such as based on frequency separation or frequency band of the channels. Once grouped as QCL, the base station performs the LBT procedure to reserve access to the one or more shared communication channels. If the LBT is successful, the base station may then transmit a channel reservation preamble on the shared communication channels in response.

Abstract: Methods, systems, and devices for wireless communications are described. One method may include receiving, by a user equipment (UE) from a base station, a resource allocation indicator corresponding to a total number of resource elements to allocate for uplink control information within a resource allocation of a shared data channel. The UE may determine anchor resources within the resource allocation, and determine a plurality of transmission parameters for an autonomous uplink transmission based on the total number of resource elements. The UE may transmit, to the base station, the uplink control information within the anchor resources to indicate the plurality of transmission parameters for the autonomous uplink transmission.

Abstract: Flexible waveform synthesis is disclosed for new radio (NR) shared spectrum (NR-SS) networks. In order to accommodate variable transmission resources, a transmitter may construct an M×N grid to model a resource element (RE) map of transmission resources available to the transmitter within a shared communication channel, where M corresponds to a number of symbols for a scheduled physical signal and N corresponds to a number of tones of a transmission bandwidth for the transmitter. The transmitter may then map the M×N grid to the RE map and puncture one or more REs associated with the subbands unavailable for transmission in the transmission resources. The transmitter may then transmit a transmission according to the unpunctured REs of the RE map.

Abstract: Methods, systems, and devices for wireless communications are described. In some wireless systems, different wireless devices may communicate using different radio access technologies (RATs) in a shared radio frequency spectrum. Prior to communicating on a channel in the shared radio frequency spectrum, a wireless device may transmit a training field as part of a preamble in a transmission on the channel to reserve the channel for the transmission. As described herein, a training field transmitted by a wireless device using one RAT may be transmitted with an autocorrelation property associated with training fields of another RAT. As such, a wireless device configured to communicate using the other RAT may be able to receive and identify the training field (e.g., based on the autocorrelation property), and the wireless device may use the additional techniques described herein to determine an availability of the channel based on the training field.

Abstract: Random access channel (RACH) configurations for new radio (NR) shared spectrum (NR-SS) networks are disclosed. A base station may perform a listen before talk (LBT) procedure on a shared communication channel at a beginning of a discovery measurement timing configuration (DMTC) window. In response to a successful LBT, the base station may transmit synchronization signals over a plurality of directional beams according to a predetermined sequence. The user equipment (UE) may determine the predetermined sequence through the detected synchronization signals. The base station may signal configuration of additional random access resources when the LBT procedure delays beyond dedicated random access resources. The base station may then monitor for UEs to transmit random access signals from each direction corresponding to directional beams within the additional random access resources according to the predetermined sequence.

Abstract: Methods, systems, and devices for wireless communications are described. A wireless device may include a plurality of antenna panels. The wireless device may perform a first listen before talk (LBT) procedure for a configuration of a first antenna panel based at least in part on a first LBT timer and may perform a second LBT procedure for a configuration of a second antenna panel based at least in part on a second LBT timer. The wireless device may then perform a multiple user multiple-input multiple-output (MU-MIMO) transmission. The MU-MIMO transmission may include transmitting a first packet to a second wireless device using the configuration of the first antenna and transmitting a second packet to a third wireless device using the configuration of the second antenna.

Abstract: Methods, systems, and devices for wireless communication are described. A base station may configure a system bandwidth of shared spectrum partitioned into a plurality of bandwidth parts based on interference associated with each of the plurality of bandwidth parts. The base station may then transmit the configuration of the system bandwidth to a plurality of devices. A UE may receive, from a base station, a configuration of a system bandwidth of shared spectrum. The system bandwidth may be partitioned into a plurality of bandwidth parts based on interference associated with each of the plurality of bandwidth parts. The UE may then communicate with the base station on at least one of the bandwidth parts.

Abstract: Wireless communications systems and methods related to communicating in a shared communication medium with flexible scheduling are provided. A first wireless communication device communicates, with a second wireless communication device during a reservation period, a channel reservation request for a first transmission opportunity (TXOP) in a spectrum. The first wireless communication device communicates, with the second wireless communication device during a response period in response to the channel reservation request, a channel reservation response. The first wireless communication device communicates, with a third wireless communication device during a first time period between the reservation period and the response period, a first communication signal.

Abstract: Methods, systems, and devices for wireless communication are described. A user equipment (UE) and a base station operating in unlicensed spectrum may temporarily increase a paging opportunity window (POW) size, or reduce a time between POWs, in order to meet performance metrics or account for time periods when a base station is unable to win access to the wireless medium during a POW. In some cases, a UE may identify a failed listen-before-talk procedure and autonomously update the POW size. In other examples, a base station may initiate a change in POW size or increase a number of paging opportunities in order to meet achieve one or more key performance indicators (KPIs). After a predetermined period, or after a triggering condition is no longer present, the UE and the base station may reset the POW size or the number of paging opportunities to a nominal amount to conserve power.

Abstract: Methods, systems, and devices for wireless communications are described. A contending wireless device may transmit a reservation request signal on the channel during a gap period associated with the channel. The contending wireless device may monitor for a reservation challenge signal resource associated with the gap period for a reservation challenge signal. A challenging wireless device may receive the reservation request signal and determine an interference risk based at least in part on the reservation request signal. The challenging wireless device may transmit a reservation challenge signal over a reservation challenge signal resource associated with the gap period based at least in part on the determination. The contending wireless device may selectively perform a transmission on the channel based at least in part on a result of the monitoring.

Abstract: In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. In one example, the apparatus may be a base station. In certain configurations, the apparatus may transmit information indicating a narrowband frequency hopping pattern to at least one UE. In certain aspects, the narrowband frequency hopping pattern may correspond to a plurality of frames. In certain other aspects, the plurality of frames may include at least one non-anchor channel and being associated with a plurality of anchor channels. The apparatus may communicate with the at least one UE using the narrowband frequency hopping pattern, including concurrently transmitting a discovery reference signal (DRS) in each of the plurality of anchor channels at a start of each hopping frame. In certain aspects, communication on the plurality of anchor channels may occur during the same frames.

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: Wireless communications systems and methods related to determining scheduling and transmission timeline for communicating in a shared communication medium are provided. A first wireless communication device communicates, with a second wireless communication device, scheduling information during a first time period of a first transmission opportunity (TXOP) of a first network operating entity in a shared communication medium, the scheduling information indicating an offset time period relative to the first time period. The first wireless communication device communicates, with the second wireless communication device, a communication signal during a second TXOP subsequent to the first TXOP based on the offset time period.

Abstract: Methods, systems, and devices for wireless communications are described. A wireless device may determine an interference status of each beam configuration of a plurality of active beam configurations for a shared radio frequency spectrum band. The wireless device may determine a beam-specific listen-before-talk (LBT) requirement for each beam configuration of the plurality of active beam configurations based at least in part on the determined interference status of each beam configuration. The wireless device may selectively enable an LBT procedure on a per-beam basis according to the determined beam-specific LBT requirement for each beam configuration.

Abstract: Certain aspects of the present disclosure relate to communication systems, and more particularly, to a control resource set (coreset) for transmitting physical downlink control channels using a single-carrier waveform in communications systems operating according to new radio (NR) technologies. In an exemplary method, a base station may determine a first control resource set (coreset) of time and frequency resources within a control region of system bandwidth, to transmit a physical downlink control channel (PDCCH) to a user equipment (UE) and transmit the PDCCH to the UE as a single-carrier waveform via the first coreset of time and frequency resources.

Abstract: Wireless communications systems and methods related to coordinating shared radio resources for spectrum sharing are provided. A spectrum resource control unit allocates a first resource for exclusive access by a first network operating entity in a spectrum. The exclusive access is configured for at least one of a network information communication or a feedback communication. The spectrum resource control unit allocates a second resource in the spectrum for shared access by the first network operating entity and a second network operating entity. The shared access is configured for at least a downlink control information communication. The spectrum resource control unit transmits, to the first network operating entity and the second network operating entity, a configuration indicating the first resource allocated for exclusive access by the first network operating entity and the second resource allocated for shared access by the first network operating entity and the second network operating entity.

Abstract: Subband based uplink access for new radio (NR) shared spectrum (NR-SS) is disclosed. A base station performs a listen before talk (LBT) procedure on system allocated subbands of a shared communication channel. The base station determines a first set of candidate subbands that are signaled to a user equipment (UE). The UE performs an LBT procedure on the first set to identify a second set of candidate subbands including the successful LBT subbands of the first set. Aspects of the disclosure provide for managing and refining the subbands for transmissions. A first aspect provides the UE to determine a transmission behavior based on mismatch between the first and second sets. A second aspect provides the first and second sets in handshaking between the base station and UE for refining the eventual transmission set of subbands. A third aspect provides cross-band LBT reporting for further refining subband selection in later slots.

Abstract: Certain aspects of the present disclosure relate to methods and apparatus for receiving ACK/NACK reporting in unlicensed IoT systems with long transmission durations. In one example, an eNodeB executes an LBT protocol to gain access to a channel of a shared spectrum, receives radio resource management (RRM) measurement reports from an IoT-U, estimates a number of repetitions used to schedule the IoT-U based on the RRM measurement, and configures the maximum number of HARQ processes that can be scheduled in a frame based on the RRM measurements and the estimate of the repetitions.