Abstract: The apparatus may be a base station. The apparatus sets a first numerology for at least one synchronization signal of one or more synchronization signals to be different from a second numerology for at least one data signal of one or more data signals. The apparatus transmits the one or more synchronization signals to a user equipment (UE) based on the first numerology. The apparatus transmits the one or more data signals to the UE based on the second numerology.

Abstract: Methods, systems, and devices for wireless communication are described. In aspects of the present disclosure, a user equipment (UE) may report metrics (e.g., received signal power, beam identifier) about synchronization signal (SS) beams using the same (e.g., or a similar) framework that is used for channel state information reference signal (CSI-RS) reporting. Because SSs are intended to be broadcast across a wide coverage area in a beamformed manner, the SSs represent a promising complement to existing beam management techniques. Accordingly, beam management may be achieved at least in part based on reporting one or more metrics of beamformed SSs through a channel feedback framework.

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 communications are described. Generally, the described techniques provide for adjusting communication timings of beams (e.g., of beam pair links) within a beam timing advance group (TAG). In some cases, a base station may determine that transmission timing at a UE may be misaligned between multiple beams. The base station may configure a set of beams into a beam TAG, and may send a timing advance (TA) command for the beam TAG. A common timing reference value may be identified based on the TA command. UEs performing uplink transmissions may determine a TA value for the beam TAG based on the common timing reference value, and may adjust a communication timing for one or more of the beams within the beam TAG based at least in part on the common timing reference value and the timing advance value.

Abstract: Methods, systems, and devices for wireless communication are described. A base station may identify two (or more) beamforming directions associated with simultaneous communications to a set of receivers. Each receiver may be associated with a different one of the two beamforming directions. The base station may schedule resources for simultaneous communications with the set of receivers based on the identified two beamforming directions. The base station may schedule simultaneous transmissions to the set of receivers using the scheduled resources.

Abstract: A base station may transmit scheduling information comprising one or more first downlink messages to a first user equipment (UE) in a first beam. The base station may transmit one or more second downlink messages to a second UE in a second beam. In response to the transmission of the one or more first downlink messages, the base station may receive one or more first uplink control messages from the first UE in a time slot. In response to the transmission of the one or more second downlink messages, the base station may receive one or more second uplink control messages from the second UE in the same time slot. The one or more second uplink control messages may be frequency-orthogonal or spreading code-orthogonal to the one or more first uplink control messages.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may initiate handover from one base station to another. The handover procedure may not include random access channel (RACH) transmissions, and thus may be a localized RACH-less handover. The UE may initiate handover to a new base station based on the relative location of the UE and the new base station, some predetermined time, or based on the characteristics of the signals from each base station.

Abstract: When beamforming (e.g., via a millimeter wave system (mmW)) is used for wireless communication, a base station may transmit beams that are directed to certain directions. Due to the directional nature of the beams in the mmW system, an approach to determine a beam that provides a desirable gain is studied. The apparatus may be a user equipment (UE). The apparatus receives, from a base station, a plurality of signals through a plurality of beams of the base station, each of the plurality of beams corresponding to a respective antenna port of a plurality of antenna ports of the base station, where the plurality of signals include a plurality of beam reference signals, a plurality of beam refinement reference signals, a plurality of channel state information reference signals (CSI-RSs), or a combination thereof. The apparatus performs channel estimation for each beam of the plurality of beams from the plurality of antenna ports based on the plurality of signals.

Abstract: Certain aspects of the present disclosure provide techniques for random-access channel (RACH) communication. For example, certain aspects provide a method for wireless communication. The method generally includes transmitting a plurality of reference signals using one or more beams, and receiving at least one of a RACH preamble and or a RACH payload corresponding to one or more of the reference signals transmitted via at least one of the one or more beams.

Abstract: Methods, systems, and devices for wireless communication are described. A base station may identify that data is available to be transmitted to a user equipment (UE) that is operating in a discontinuous reception (DRX) mode. The base station may configure a plurality of UE-specific reference signals for transmission to the UE, each UE-specific reference signal indicating a UE identifier and an availability of data for the UE. The UE may receive the UE-specific reference signal, and identify that data is available for the UE from the base station. The UE may then transmit a beam recovery signal to the base station that includes an identifier for the transmit beam used by the UE to transmit the beam recovery signal. The base station may transmit, using a beam sweeping configuration, the plurality of UE-specific reference signals.

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 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 scheduling request message to the base station using at least one of a resource or a waveform selected based at least in part on the selected DL beam.

Abstract: A method, an apparatus, and a computer-readable medium for wireless communication are provided. In some aspects, a base station may send 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 base station may send, in association with the beam modification command, a reference signal using at least one transmit beam of the set of transmit beams, where a first portion of the reference signal is sent in a first set of symbols and a second portion of the reference signal is received in a second set of symbols.

Abstract: When beamforming (e.g., via a millimeter wave system (mmW)) is used for wireless communication, a base station may transmit beams that are directed to certain directions. Due to the directional nature of the beams in the mmW system, an approach to determine a beam that provides a desirable gain is studied. The apparatus may be a user equipment (UE). The apparatus receives, from a base station, a plurality of signals through a plurality of beams of the base station, each of the plurality of beams corresponding to a respective antenna port of a plurality of antenna ports of the base station. The apparatus receives from the base station a number of beams whose information should be fed back to the base station. The apparatus performs channel estimation for each beam of the plurality of beams from the plurality of antenna ports based on the plurality of signals.

Abstract: Techniques are provided for power control in directional beam environments. A user equipment (UE) may determine one or more power parameters on a beam-by-beam basis. Each directional uplink transmission beam in a communication link between the UE and the base station may be independently controlled using these beam-specific power parameters. Examples of these beam-specific power parameters may include a maximum output power for a given directional uplink transmission beam and a difference between the maximum output power for the given directional uplink transmission beam and an estimated transmit power for the given directional uplink transmission beam. The UE may report one or more of these beam-specific power parameters to a base station using a beam-specific report.

Abstract: Methods, systems, and devices for wireless communication are described. A base station may transmit, to a user equipment (UE) operating in a discontinuous reception mode, a wakeup signal indicating whether data is available to be transmitted to the UE, the wakeup signal transmitted using a first set of transmit beams, which may be selected from a periodic beam management procedure, in accordance with a beam sweeping configuration. The base station may receive, from the UE and based at least in part on the wakeup signal, a response signal. The base station may perform, based at least in part on the response signal, further beam update procedures to identify a second set of transmit beams for future transmissions of the wakeup signal and/or for transmission of physical downlink control channel (PDCCH) to the UE.

Abstract: Methods, systems, and apparatuses are described for a base station initiated control mechanism for supporting supplemental a link. In some aspects, control information associated with a directional, first radio access technology (RAT) for a user equipment (UE) may be identified at a first base station, the first base station configured to communicate with the UE using the directional, first RAT, and the control information associated with the directional, first RAT may be transmitted to a second base station to forward to the UE using a second RAT.

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 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: 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: 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.