Abstract: Techniques are described for wireless communication. In one method, a user equipment (UE) receives a timing synchronization signal (TSS) and a physical broadcast channel (PBCH), with the TSS based at least in part on a timing of the TSS within a broadcast channel transmission time interval (BCH TTI); determines the timing of the TSS within the BCH TTI; and demodulates the PBCH based at least in part on the TSS. In another method, a base station allocates resources for a TSS and a PBCH within a BCH TTI; determines the TSS based at least in part on a timing of the TSS within the BCH TTI; and transmits, on the resources allocated for the TSS and the PBCH, the TSS and the PBCH, with the TSS transmitted as a demodulation reference signal (DMRS) for the PBCH on at least one port used to transmit the TSS and the PBCH.

Abstract: Methods, systems, and devices for wireless communication are described. In multi-user (MU) multiple-input multiple-output (MIMO) wireless communications systems, a base station may perform signaling to indicate information related to ports assigned to one or more UEs. The base station may also signal information regarding ports shared with other UEs, which the UE may use when performing channel estimation. In some examples, the base station may signal a number of ports used per sub-band to the UE or a number of demodulation reference signal (DMRS) ports used by the UE. The base station may signal a sub-set of a total number of ports that are shared by other UEs overlapping with the resource allocation of the UE. The signaling may indicate a number of combs used by the base station in the resource allocation for the UE.

Abstract: Certain aspects of the present disclosure provide techniques for protecting high priority symbols from beam switching. In some aspects, a method comprises identifying potential beam switching time spots in a time interval. The method further comprises determining a time interval configuration of the time interval based on the identified potential beam switching time spots, wherein the time interval configuration protects one or more high priority symbols from beam switching at the potential beam switching time spots. The method further comprises transmitting the time interval configuration to a user equipment (UE).

Abstract: Disclosed are techniques for transmitting reference signals (RS) for positioning. A method comprises transmitting or providing an instruction to transmit a first set of RS to a user equipment (UE) in accordance with a first set of RS transmission parameters, receiving a report containing information indicating whether a measurement performed by the UE is limited by a signal-to-noise ratio (SNR) of the first set of RS or a bandwidth of the first set of RS, determining a second set of RS transmission parameters using the received report, wherein the second set of RS transmission parameters is different from the first set of RS transmission parameters, and transmitting a second set of RS to the UE in accordance with the second set of RS transmission parameters, or providing the second set of RS transmission parameters to a base station.

Abstract: Certain aspects of the present disclosure relate to methods and apparatus synchronization configuration in different operation modes using communications systems operating according to new radio (NR) technologies. For example, a method for wireless communications by a base station (BS) may include determining an operation mode of the BS, determining a transmission configuration of at least one of a one or more synchronization channels or a one or more synchronization signals based on the operation mode, and transmitting the one or more synchronization channels or the one or more synchronization signals based on the determined transmission configuration.

Abstract: Certain aspects of the present disclosure relate to methods and apparatus for radio link monitoring reference signal (RLM-RS) determination using communications systems operating according to new radio (NR) technologies. For example, a method for wireless communications from a UE generally includes determining resources to monitor for radio link monitoring (RLM) prior to being configured with resources to monitor for RLM after establishing a radio resource control (RRC) connection with a network, and performing RLM based on the determined resources.

Abstract: Disclosed are techniques to determine angle of departure (AoD) of signals transmitted from a set of transmission points associated with a transmitter (e.g., a base station, a user equipment (UE)). In an aspect, the set of transmission points are collocated and transmit coherent signals. A receiver (e.g., UE, network entity) determines phase difference of arrivals (PDoAs) of the signals. Based on the PDoAs and locations of the set of transmission points, the AoD can be calculated. When the UE is the receiver, the network entity can send a base station almanac (BSA) message to the UE indicating the set of transmission points and their locations.

Abstract: Methods, systems, and devices for wireless communication are described. A network device, such as a base station, may transmit a request message to a user equipment (UE). The request message may include a request for the UE to transmit a set of sounding reference signals (SRSs). The set of SRSs may include two (or more) beamformed signals. The network device may receive the set of SRSs according to the request message. The network device may identify, based on a co-phasing parameter associated with the two (or more) beamformed signals, an antenna port precoder configuration to use for communicating with the UE.

Abstract: Methods, systems, and devices for wireless communication are described that provide for selecting different uplink transmission parameters for transmission or retransmission of a random access message. A user equipment (UE) may retransmit a random access message to a base station during a random access procedure if an initial transmission of the random access message was unsuccessfully received by the base station. The UE may select a different transmission beam, uplink resource, or transmission power for retransmission of the random access message. The selection may be based on path loss associated with synchronization signals or previous transmissions. The selection may also be based on a maximum number of retransmissions.

Abstract: A UE may receive, from a base station, a message requesting BSI. The UE may determine a number N of BSI reports to send to the base station, and each BSI report may indicate a beam index corresponding to a beam and a received power associated with the beam. The UE may send, to the base station, N BSI reports based on the message requesting BSI. The UE may receive, from the base station, a set of signals through a set of beams, and determine the received power for each signal of the set of signals received through each beam of the set of beams, each received power may be associated with a beam of the set of beams.

Abstract: A UE may receive a beam modification command that indicates a set of transmit beam indexes corresponding to a set of transmit beams of a base station, and each transmit beam index of the set of transmit beam indexes may indicate at least a transmit direction for transmitting a transmit beam by the base station. The UE may determine a set of receive beam indexes corresponding to receive beams of the UE based on the set of transmit beam indexes, and each receive beam index of the set of receive beam indexes may indicate at least a receive direction for receiving a receive beam by the UE. The UE may receive, from the base station, a signal through at least one receive beam corresponding to at least one receive beam index included in the set of receive beam indexes.

Abstract: Various aspects of the disclosure relate to communicating uplink control information. As one example, a user equipment may send uplink control information to a base station. In some aspects, the number of symbols used to communicate the uplink control information may be based on a link gain associated with the UE and/or based on a payload size of the uplink control information. As another example, the user equipment may send channel information for a number of beams to the base station. In some aspects, the number of beams may be based on the type of channel that is used to send the uplink control information.

Abstract: Methods, apparatuses, and computer-readable mediums associated with a user equipment (UE) and a base station are provided for herein. In aspects, a UE may receive, from a base station, a beam modification command indicating at least one beam index for communicating through at least one beam on a channel and indicating the channel corresponding to the at least one beam. In an aspect, each beam index of the at least one beam index indicating at least a direction for communicating through a corresponding beam of the at least one beam, where the beam modification command may be received in a MAC CE. The UE may communicate, with the base station, through the at least one beam corresponding to the at least one beam index on the channel.

Abstract: A first apparatus may transmit, to a user equipment (UE), on a control channel, one or more indications of one or more beam indexes corresponding to one or more beams. The first apparatus may transmit, to the UE, one or more reference signals through the one or more beams corresponding to the one or more beam indexes. The reference signals may be used by the UE to select a best subarray and/or receive combiner for communication with the first apparatus.

Abstract: Methods, systems, and devices for multiple random access channel (RACH) message 1 (Msg1) transmission for physical downlink control channel (PDCCH) ordered RACH are described. A user equipment (UE) may perform the multiple Msg1 transmission as part of a CFRA or CBRA procedure for access. The UE may perform the multiple Msg1 transmissions in a cyclic consecutive manner during configured RACH occasions or according to explicit time and frequency indications of a random access response (RAR) window. Based on the multiple Msg1 transmission procedure, the UE may reduce latency for random access procedure on the RACH and improve signaling throughput. In some cases, the UE may support beam correspondence and may perform multiple Msg1 transmissions to enhance multi-beam diversity during RACH transmission by performing transmission corresponding to RACH occasions mapped to different synchronization signal blocks (SSBs).

Abstract: Certain aspects of the present disclosure provide techniques for assisted power control for an uplink signal transmitted during a RACH procedure. A UE may determine a transmit power for transmitting a message during a RACH procedure with a secondary BS, based at least in part, on communication between the UE and a primary BS. The UE may transmit the message to the second BS during the RACH procedure based, at least in part, on the determined transmit power.

Abstract: A first apparatus may send, to a base station in a first carrier frequency, a request associated with determination of a first beam used for communication between the base station and the UE. The first apparatus may communicate with the base station in a second carrier frequency based on the request associated with the determination of the first beam, the first carrier frequency being different from the second carrier frequency. A second apparatus may receive, from a base station in a first carrier frequency, a message associated with determination of a first beam used for communication between the base station and the UE. The second apparatus may communicate with the base station in a second carrier frequency based on the message associated with the determination of the first beam, the first carrier frequency being different from the second carrier frequency.

Abstract: One apparatus may be configured to detect a set of beams from a base station. The apparatus may be further configured to select a beam of the set of beams. The apparatus may be further configured to determine at least one resource based on the selected beam. The apparatus may be further configured to transmit, on the at least one determined resource, a beam adjustment request to the base station. The request may indicate an index associated with the selected beam. Another apparatus may be configured to transmit a first set of beams. The other apparatus may be further configured to receive a beam adjustment request on at least one resource. The other apparatus may be further configured to determine a beam index of a beam in the first set of beams based on the request and the at least one resource.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first wireless node may receive, from a second wireless node, a round-trip time timing advance indicator, wherein the round-trip time timing advance indicator is different from a timing advance indicator used for an uplink transmission timing advance message. In some aspects, the first wireless node may synchronize a timing configuration of the first wireless node to at least one of the second wireless node or a third wireless node based at least in part on the round-trip time timing advance indicator. Numerous other aspects are provided.

Abstract: Methods, systems, and devices for wireless communication are described. A user equipment (UE) may receive a downlink (DL) signal from a base station on one or more DL beam(s). The UE may identify of a nature of correspondence between one or more receive beams at the UE and one or more transmit beams at the UE. The UE may identify a selected DL beam of the one or more DL beam(s) for communications from the base station to the UE. The UE may transmit a random access channel (RACH) message to the base station using a resource and/or a RACH waveform selected based on the selected DL beam based at least in part on the selected DL beam and the nature of correspondence.