Abstract: Wireless communications systems and methods related to synchronization signal (SS) transmission coordination among base stations (BSs) and restricted SS measurements at user equipments (UEs) are provided. A first BS transmits a first SS burst in a first SS transmission period of a plurality of SS transmission periods. The first SS transmission period is designated to the first BS. A second SS transmission period of the plurality of SS transmission periods is designated to a second BS. The first SS transmission period and the second SS transmission period are different. The first BS receives, from a UE, a first signal in synchronization with the first SS burst. The first signal includes a SS measurement of the first SS burst.

Abstract: Techniques are disclosed for handover of a user equipment (UE) from a serving base station to a target base station. A target base station may use one or more directional beams to establish wireless communication links with UEs within a coverage area of the target base station. Directional beams may create a narrow-beam, high-bandwidth connection with a UE in a limited geographic area. Handover procedures include some latency between when a target base station dedicates resources to a UE and when the UE executes a communication via those dedicated resources. To compensate for latencies in a handover procedure and for the geographic limitations of directional beams, a target base station may assign multiple directional beams to the UE during a handover procedure. Each directional beam may be associated with access parameters used by the UE to generate messages (e.g., a RACH message) during the handover procedure.

Abstract: Aspects of the disclosure relate to beam failure recovery requests. In one example, a beam failure of a beam is detected, and a determination is made of which beam failure recovery resources to utilize for a beam failure recovery request based on a network configuration. The beam failure recovery request can be transmitted via beam failure recovery resources. In another example, a scheduling entity determines beam failure conditions associated with detecting a beam failure, and ascertains a network configuration for a scheduled entity that can include parameters associated with the beam failure conditions, as well as parameters associated with determining beam failure recovery resources or for transmitting a beam failure recovery request. Other aspects and features are also claimed and described.

Abstract: Certain aspects of the present disclosure relate to methods and apparatus for beam recovery and radio link failure (RLF) in communications systems using beamforming and operating according to new radio (NR) technologies. An exemplary method that may be performed by a UE includes communicating using beamforming with a base station (BS) via a transmit beam and a receive beam of an active beam pair and obtaining an indication of one or more alternative beams for the UE to use to send a beam recovery message to the BS in the event the transmit beam and the receive beam of the active beam pair become misaligned.

Abstract: Methods, systems, and devices for wireless communication are described. Wireless communications systems may support beamformed transmissions between devices (e.g., to improve coverage range). The beamformed transmissions may depend on discovery and maintenance of receive and transmit beams over which a given device may communicate with another device. Various receive and transmit beams for a given device may be compared using reference signals. As the number of devices attempting to access a cell increases, the number of reference signals to be transmitted may scale proportionally. Large numbers of reference signals may flood time-frequency resources of the system and/or require excessive processing at a mobile device. Scrambling sequences for reference signals may be employed to improve efficiency of resource usage. In aspects, the scrambling sequences may be implicitly determined (e.g., based on resources over which the access request was transmitted).

Abstract: The present disclosure describes a method, an apparatus, and a computer-readable medium for a random access channel (RACH) procedure at a user equipment. For example, the method may select a two-step RACH procedure or a four-step RACH procedure at the UE based at least on RACH configuration information received from a base station or the RACH configuration information at the UE. The example method may further include transmitting, from the UE, one or more messages associated with the two-step RACH procedure or the four-step RACH procedure based on the selection.

Abstract: Methods, systems, and devices for wireless communications are described. A base station may identify time and frequency resources for a physical downlink shared channel (PDSCH) to be transmitted to a user equipment (UE) in a first transmission time interval (TTI). The base station may transmit configuration information for a control channel search space set in a second TTI. The second TTI may precede the first TTI. The configuration information may include an indication of an absence of a physical downlink control channel (PDCCH) transmission to send in the control channel search space set indicating the identified time and frequency resources for the PDSCH, and a set of time and frequency resources for the control channel search space set. The UE may receive the configuration information and identify the time and frequency resources allocated for the PDSCH in the second TTI, and receive the PDSCH transmission in the second TTI.

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: Methods, systems, and devices for wireless communications are described. A base station may identify time and frequency resources for a physical downlink shared channel (PDSCH) to be transmitted to a user equipment (UE) in a first transmission time interval (TTI). The base station may transmit configuration information for a control channel search space set in a second TTI. The second TTI may precede the first TTI. The configuration information may include an indication of an absence of a physical downlink control channel (PDCCH) transmission to send in the control channel search space set indicating the identified time and frequency resources for the PDSCH, and a set of time and frequency resources for the control channel search space set. The UE may receive the configuration information and identify the time and frequency resources allocated for the PDSCH in the second TTI, and receive the PDSCH transmission in the second TTI.

Abstract: Methods, systems, and devices for wireless communication are described. In some wireless communications systems, a user equipment (UE) may be configured to transition to communicating on a first bandwidth part from communicating on a second bandwidth part. In order to ensure that the UE is able to perform receiver processing for demodulating data received on the first bandwidth part, after transitioning to communicating on the first bandwidth part, the UE may be configured to perform receiver processing using reference signals received on the second bandwidth part. That is, for a configured period of time, before the UE is able to perform receiver processing for demodulating data received on the first bandwidth part using reference signals received on the first bandwidth part, the UE may perform receiver processing for demodulating data received on the first bandwidth part using reference signals received on the second bandwidth part.

Abstract: The present disclosure describes a method, an apparatus, and a computer-readable medium for a random access channel (RACH) procedure at a user equipment. For example, the method may select a two-step RACH procedure or a four-step RACH procedure at the UE based at least on RACH configuration information received from a base station or the RACH configuration information at the UE. The example method may further include transmitting, from the UE, one or more messages associated with the two-step RACH procedure or the four-step RACH procedure based on the selection.

Abstract: Methods, systems, and devices for wireless communication are described. A base station may initiate a beam management procedure, including reference signal transmission to a user equipment (UE) and receive beam training. A base station may configure a UE to monitor a set of beams for reference signals. Based on the received reference signals, the UE may optionally select one or more transmit beams for wakeup signal reception, and may transmit an indication of the selected beams to the base station. The base station may transmit a wakeup signal over the originally configured or the UE-selected transmit beams to initiate wake-up procedure at the UE. The base station and UE may subsequently perform a refined beam management procedure, providing a refined reference signal transmission from the base station. Based on the received transmission, the UE may select a refined beam for downlink transmissions.

Abstract: Certain aspects of the present disclosure provide to techniques for radio link monitoring (RLM), detecting beam failure, and beam failure recovery (BFR) using radio link monitoring reference signal (RML-RS) resources and beam failure recovery reference signal (BFR-RS) resources. An exemplary method by a user equipment (UE) may include obtaining a first configuration indicating one or more radio link monitoring reference signal (RLM-RS) resources and one or more beam failure recovery reference signal (BFR-RS) resources, wherein each RLM-RS resource corresponds to at least a first link, and each BFR-RS resource corresponds to at least a second link, obtaining a first indication that a first link quality for the first link is below a first threshold and a second link quality for the second link is above a second threshold, and taking action regarding a radio link failure (RLF) based on the indication.

Abstract: Methods, systems, and devices for wireless communication are described. A base station may partition a plurality of carriers into one or more groups. Each carrier within a group may share one or more antenna panels so as to each be directed by a transmit beam in a same direction. The base station may transmit to a user equipment a carrier group indication that identifies the partitioning of the plurality of carriers into the one or more groups and maps a group identifier for at least one of the one or more groups to a beam identifier that identifies the corresponding transmit beam.

Abstract: Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a first apparatus may detect a beam failure of a first link between the first apparatus and a second apparatus; transmit a beam failure recovery request indicating the beam failure of the first link, wherein the beam failure recovery request is transmitted via a second link of the first apparatus; and perform a beam failure recovery procedure, to select one or more beams for communication between the first apparatus and the second apparatus, based at least in part on transmitting the beam failure recovery request via the second link. Numerous other aspects are provided.

Abstract: Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a UE may measure a first reference signal, associated with a frequency band of a long term evolution (LTE) system, and a second reference signal associated with a frequency band of a new radio (NR) system. The frequency band of the NR system may overlap the frequency band of the LTE system. The UE may determine first channel state feedback, associated with the frequency band of the LTE system, and second channel state feedback, associated with the frequency band of the NR system, based at least in part on the first reference signal and the second reference signal, respectively. The UE may report the first channel state feedback or the second channel state feedback in uplink control information (UCI). Other aspects are provided.

Abstract: Methods, systems, and devices for wireless communications provide for transmission of a beam switch command to a user equipment (UE) via control channel signaling. The UE may establish a connection with a base station using a first transmission beam, receive configuration information configuring the UE to select between a first decoding hypothesis corresponding to downlink control information (DCI) including a bit field including a beam switch command and a second decoding hypothesis corresponding to the DCI not including the bit field, receive a downlink control channel transmission via the first transmission beam, decode the downlink control channel transmission in accordance with the configuration information to obtain decoded DCI, and communicate with the base station based at least in part on the decoded DCI.

Abstract: Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may provide information identifying a first time offset between a first time associated with a measurement performed by the user equipment and a second time associated with a measurement gap or a time value of a serving cell of the user equipment, receive information identifying a second time offset between the second time and a third time, wherein the second time offset is based at least in part on the first time offset, and/or transmit a random access message at the third time based at least in part on the second time offset. A scheduling entity may coordinate a random access procedure associated with the random access message based at least in part on the second time offset. Numerous other aspects are provided.

Abstract: A wireless communications system may support beamforming to transmit and receive signals. A device operating within the wireless communications system may transmit a request to measure a beamformed reference signal. The device may also transmit a beamforming configuration indicating one or more beamforming options for measuring the beamformed reference signal. The beamforming options may include measuring the beamformed reference signal using a directional configuration and an omni-directional configuration. The device receiving the beamforming configuration may form a receive beam in accordance with the beamforming configuration to measure the beamformed reference signal. A device operating within the wireless communications system may determine to use a particular beamforming option for measuring a beamformed reference signal without first receiving a beamforming configuration, and may make the determination based on signal quality at the device or capabilities of the device.

Abstract: Methods, systems, and devices for wireless communication are described for event triggering and reporting with multiple reference signals. A user equipment (UE) may receive event configuration data that specifies at least one permitted combination of reference signals of different types for generating a signal quality comparison and receive a first reference signal and a second reference signal. The UE may generate signal quality comparison data based at least in part on the event configuration data, the first reference signal, and the second reference signal, and transmit a report to a base station that includes the signal quality comparison data.