Abstract: Methods, systems, and devices for wireless communications are described that provide for aggregating random access requests across two or more physical random access channel (PRACH) occasions. Poor channel quality may inhibit the receipt of random access requests, and for user equipments (UEs) located in areas with relatively poor coverage, such aggregated random access requests may have an increased likelihood of successful receipt at a base station. The base station may configure a number of PRACH occasions to be available for aggregation of random access requests. A UE may receive PRACH configuration information from the base station, may aggregate a random access request across two or more PRACH occasions using the PRACH configuration information, and may transmit the aggregated random access request via the PRACH occasions. The base station may also configure one or more PRACH occasions to have a smaller subcarrier spacing for transmission of a random access request.

Abstract: A method of wireless communication may include transmitting an uplink slot with a first control region, a second control region, and (e.g., optionally) a data region. Each region may include time resources and frequency resources. Transmitting the uplink slot may include transmitting the first control region in an earlier part of the uplink slot and transmitting the second control region (e.g., and the data region) in a later part of the uplink slot. The first control region may include time-critical control information and the second control region may include non-time-critical control information. A receiver receiving the uplink slot may receive the first control region before receiving the data region and the second control region.

Abstract: Wireless communications systems and methods related to on-demand cell coverage extension for broadcast signals are provided. A first wireless communication device communicates, with a second wireless communication device, a first extended cell coverage request. The first wireless communication device communicates, with the second wireless communication device, a first broadcast communication signal in an extended cell coverage mode in response to the first extended cell coverage request. The first broadcast communication signal includes a system information block repeated in at least one of a time domain or a frequency domain.

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: Aspects of the present disclosure describe receiving an indication of a covariance matrix from an access point, receiving downlink signaling from the access point, deriving, based at least in part on the covariance matrix or the downlink signaling, one or more precoders for uplink communications over an uplink channel, and indicating, based at least in part on the one or more precoders, uplink channel feedback to the access point.

Abstract: Phase compensation in a new radio (NR) coordinated multipoint (CoMP) environment is discussed. A base station may synchronize the phase between one or more additional base stations in a CoMP group serving one or more user equipments (UEs). A base station estimates an uplink channel based on a sounding reference signal (SRS) received from a given UE. The base station transmits a phase synchronization reference signal (PSRS) modulated using the uplink channel estimate. The UE can measure the phase and/or timing drift from the PSRS and then will report the compensation information for the phase and timing drift back to the base station. The base station may then use the compensation information to adjust transmission characteristics for the CoMP group.

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: A method of wireless communication may include transmitting an uplink slot with a first control region, a second control region, and (e.g., optionally) a data region. Each region may include time resources and frequency resources. Transmitting the uplink slot may include transmitting the first control region in an earlier part of the uplink slot and transmitting the second control region (e.g., and the data region) in a later part of the uplink slot. The first control region may include time-critical control information and the second control region may include non-time-critical control information. A receiver receiving the uplink slot may receive the first control region before receiving the data region and the second control region.

Abstract: Various aspects described herein relate to small cyclic delay diversity (SCDD) operation used in a wireless communication system (e.g., 5G New Radio). A method, a computer-readable medium, and an apparatus are provided. In an aspect, the method, computer-readable medium, or apparatus operates to identify a type of information for transmission, identify a rank associated with the type of information, and perform an SCDD precoding operation based at least in part on the identified type of information or the rank.

Abstract: A base station may provide both an uplink grant and a downlink grant in a same transmission time interval (TTI), and may provide an indication in the uplink grant that the TTI includes the downlink grant. A user equipment (UE) that receives the uplink grant may provide feedback using identified feedback resources in an uplink shared channel, and other uplink transmissions may be rate matched around the feedback resources in the uplink shared channel. A base station receiving the feedback may monitor the feedback resources to determine whether the downlink grant or one or more of the downlink transmissions were successfully received at the UE. A base station, in some examples, may monitor different sets of resources to determine whether certain of the uplink grant, downlink grant, downlink transmissions associated with the downlink grant, or any combinations thereof, have been successfully received at the UE.

Abstract: Over-the-air phase synchronization for reciprocity-based coordinated multipoint (CoMP) joint transmission is discussed. The base stations of the CoMP group and served user equipment (UEs) transmit phase synchronization reference signals (PSRS). The receiving nodes compute wideband co-phasing values representing the phase difference between pairs of the PSRS over each tone of a whole spectrum band, and slope values based on the per-tone co-phasing values. The UEs feedback the wideband downlink co-phasing value and the downlink slope value. The base stations of the CoMP group determine a phase compensation based on the differences between the slope value calculated by the base station and the slope value reported by the UE, and based on the differences between the wideband co-phasing value calculated by the base station and the wideband co-phasing value reported by the UE. The base station uses the phase compensation to adjust communications by the base stations in the CoMP group.

Abstract: Wireless communications systems and methods related to multiplexing uplink control channel signals from different users are provided. A first wireless communication device obtains an uplink control channel multiplex configuration indicating a first frequency spreading sequence and at least one of a second frequency spreading sequence or a first spatial direction. The first wireless communication device communicates, with a second wireless communication device, a first uplink control channel signal including a first reference signal and a first uplink control information signal in a frequency spectrum based on the uplink control channel multiplex configuration. The first reference signal is based on the first frequency spreading sequence and the first uplink control information signal is based on at least one of the second frequency spreading sequence or the first spatial direction.

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: Wireless communications systems and methods related to signaling medium reservation information medium sharing among multiple radio technologies (RATs) are provided. A wireless communication device of a first RAT detects a channel reservation signal of a second RAT in a spectrum shared by the first RAT and the second RAT. The wireless communication device determines whether the channel reservation signal indicates a first transmission opportunity (TXOP) duration or a second TXOP duration that is different from the first TXOP duration. The wireless communication device selects, based on the determination, at least one of performing a backoff or continuing to monitor the spectrum.

Abstract: Methods, systems, and devices for wireless communications are described. A base station may determine a set of power control parameters for a user equipment (UE) to use in different power control loops. The base station may indicate a power control process for the UE to perform in downlink control information. The UE may identify a subset of the power control parameters to use in a power control loop for the indicated process. In some examples, the power control parameters may be for different sounding reference signal processes, such as uplink channel sounding, downlink channel sounding with channel reciprocity, or cross-link interference. In some other examples, the power control parameters may be for power control loops of different uplink channel configuration. The base station may convey the set of power control parameters to the UE by radio resource control signaling.

Abstract: Methods, systems, and devices for wireless communication are described. A base station may establish a transmission gap between downlink (DL) and uplink (UL) transmissions on a shared radio frequency (RF) spectrum band using time division duplex (TDD). The gap length may be based at least in part on a maximum allowed length of a filler signal corresponding to a coverage area of the base station. To reserve the shared band, a user equipment (UE) may communicate the filler signal for a length of time that is based at least in part on the maximum allowed length and a geographic distance between the UE and the base station. UEs farther from the base station transmit the filler signal of shorter lengths before sending an UL transmission, so that the UL transmissions from different UEs arrive at the same time at the base station regardless of the geographic distance between the UEs.

Abstract: A universal Channel Reservation Signal (CRS) is transmitted by a wireless network node on a frequency channel upon successful Clear Channel Assessment (CCA). The channel reservation signal includes a preamble that has a predetermined pattern, a message having a same short period waveform as the preamble, and a synchronization field (SYNC) disposed between the preamble and the message. The message is encoded to prevent any and all occurrences therein of at least one of the predetermined pattern or a combination of the predetermined pattern and at least part of the SYNC. The universal CRS can be transmitted and successfully received and processed by both NR-SS devices and devices of at least one other wireless communication protocol having a different numerology, such as WiFi. Thus, information can be shared and used to avoid transmitting or to reduce or avoid collisions and interference between devices of different RATs.

Abstract: Certain aspects of the present disclosure relate to methods and apparatus for transmitting channel reservation signals. In one example, a device used a gating interval to gain access to a channel of a shared spectrum, performs a clear channel assessment to determine if the channel is available, selects a channel reservation signal from among a plurality of predetermined said channel reservation signals if the channel is clear, and transmits the channel reservation signal upon the channel being clear. The channel reservation signal comprises a preamble, and a message, wherein the CR preamble and the CR message use a common numerology understood by at least one of different radio access technologies, and different numerologies in the same radio access technology, and the radio access technologies comprise WIFI and NR-SS.

Abstract: Methods, systems, and devices for wireless communication are described. A base station may establish a transmission gap between downlink (DL) and uplink (UL) transmissions on a shared radio frequency (RF) spectrum band using time division duplex (TDD). A length of the gap may be based at least in part on a maximum allowed length of a filler signal corresponding to a coverage area of the base station. To reserve the shared band, a user equipment (UE) may communicate the filler signal for a length of time that is based at least in part on the maximum allowed length and a geographic distance between the UE and the base station. UEs farther from the base station transmit the filler signal of shorter lengths before sending an UL transmission, so that the UL transmissions from different UEs arrive at the same time at the base station regardless of the geographic distance between the UEs.

Abstract: Methods, systems, and devices for wireless communication are described. A user equipment (UE) may transmit a precoded reference signal to prevent interference with an incoming signal from a base station. The UE may determine a precoder for the reference signal based at least in part on a whitening matrix. In some examples, the UE may determine the precoder based at least in part on the whitening matrix and an effective channel between the base station and the UE. The precoded reference signal may be used by devices in other wireless communications systems to avoid interfering with a signal being received by the UE. In some examples, the UE may alternatively or additionally transmit an indication of the number of additional layers of the link between the UE and the base station that may be nulled out for a second link.