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: Certain aspects of the present disclosure generally relate to wireless communications and, more particularly, to methods and apparatus for code rate selection for control channels. An exemplary method generally includes selecting, from a set of code rates, a code rate to be used to encode a stream of bits using a polar code, based on at least one of a downlink control channel aggregation size, an uplink control channel assignment, or a payload size of the stream of bits, encoding the stream of bits using the polar code and the selected code rate, and transmitting the encoded stream of bits.

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 provide techniques for reporting information regarding receive (Rx) beams used by a user equipment. In some cases, such reporting may indicate a change in Rx beams to be used by the UE for subsequent beamformed transmissions.

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 by a user-equipment (UE). The method generally includes transmitting a first message comprising a RACH preamble, receiving a second message comprising random access response (RAR) in response to the RACH preamble, transmitting a third message in response to the RAR, receiving a fourth message (MSG4) comprising a contention resolution message in response to the third message. In certain aspects, the fourth message may include a timing advance (TA) parameter which may be used to communicate one or more messages.

Abstract: Certain aspects of the present disclosure relate to methods and apparatus for dynamic reclamation of resources reserved for forward compatibility using communications systems operating according to new radio (NR) technologies. Certain aspects provide a method for wireless communication. The method generally includes identifying resources previously reserved for forward compatibility (FC) that are available for reuse, and providing signaling, to one or more user equipments (UEs), indicating the identified resources are available for reuse.

Abstract: Methods, systems, and devices for wireless communication are described. Wireless communications systems may support uplink random access channel (RACH) transmissions on multiple beams and over multiple component carriers (CCs). A wireless device may transmit a random access preamble to a base station in a first RACH transmission, which may indicate a set of CCs over which the base station may respond with a random access response (RAR) in a second RACH transmission. The second RACH transmission may then include an indication for which CCs the wireless device may use for a subsequent RACH transmission (e.g., a RACH message 3). The wireless device may also indicate a beam index and/or time-frequency resources associated with beams and/or CCs used for such cell acquisition transmissions. In other examples, the base station may indicate resources (e.g., via a handover command or RACH command) for wireless device scheduling request and/or beam-failure recovery request transmission.

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 provide techniques for selecting an uplink (UL) transmit beam by a user equipment (UE). A UE may receive, from a base station (BS), one or more beamformed downlink signals using one or more receive beams. The UE may select an uplink transmit beam based, at least in part, on the one or more beamformed downlink signals. The UE may transmit an uplink signal using the selected uplink transmit beam.

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. The network configuration can be transmitted to the scheduled entity to facilitate transmitting a beam failure recovery request. Other aspects and features are also claimed and described.

Abstract: A node for wireless communication identifies a number of actually transmitted reference signals. The node identifies a number of available PRACH time-frequency resources and preamble indices in a time period. The node identifies a number of configured PRACH time-frequency resources or PRACH preamble indices per reference signal. The node determines that the available number of PRACH time-frequency resources or PRACH preamble indices within the time period is not an integer multiple of the product of the number of actually transmitted reference signals and the number of configured PRACH time-frequency resources or PRACH preamble indices per reference signal. The node maps the actually transmitted reference signals to the available PRACH time-frequency resources and preamble indices based on the identified information and determination.

Abstract: An apparatus capable of performing a local operation in a low-interference environment is desired. In an aspect, the apparatus may be a user equipment (UE). The UE transmits a local operation notification to a base station, the local operation notification indicating a local operation that is local to the UE. The UE receives, from the base station, a resource indicator indicating one or more resources available for the local operation. The UE performs the local operation using the one or more resources.

Abstract: Techniques for performing reference signal measurement filtering in systems that support multi-beam operation are provided. A method for wireless communication by a base station (BS) includes determining at least one beam configuration for measuring reference signals transmitted from the apparatus, and signaling the beam configuration(s) to at least one user equipment (UE). A method for wireless communication by a UE includes receiving, from a BS, at least one beam configuration for measuring reference signals from the BS, and performing a measurement procedure for reference signals received from the BS based at least in part on the beam configuration(s).

Abstract: A user equipment apparatus determines whether a transmission is received from a base station within a time window and skips measurement of a reference signal during a subsequent period, when a transmission is received from the base station within the time window. A base station apparatus configures a UE to monitor one or more reference signals associated with a beam pair link and transmits a first signal in a transmission to the UE. The base station determines whether the transmission is received at the UE within a time window and determines whether to transmit a reference signal, based on whether the transmission is received at the UE within the time window. Upon determining that the transmission was received at the UE, the base station may skip transmission of the reference signal or modify a time, a frequency, a power, and/or a reference signal offset for the reference signal.

Abstract: Aspects of the present disclosure relate to receiver beamforming for serving and neighbor cell measurements. An exemplary method generally includes communicating with one or more base stations using a first beam type, initiating a transition to communicating with at least one of the one or more base stations using a second beam type in response to an indication of a trigger event, and communicating with the at least one of the one or more base stations using the second beam type.

Abstract: Methods, systems, and devices for wireless communication are described. A user equipment (UE) capable of supporting multiple antenna ports may determine that some combinations of antenna ports can be used simultaneously. The UE may make this determination by evaluating the relationships between the physical antennas and the transmit chains included in the UE. Upon determining that the combinations of antenna ports can be used simultaneously, the UE may send a message to a base station. The message may indicate whether two or more antenna ports can be used at the same time. The UE may communicate simultaneously over one or more antenna ports based on the scheduling information from the base station which takes into account the ability of the combination of antenna ports to be used concurrently.

Abstract: Certain aspects of the present disclosure provide techniques for assisting a UE in measuring reference signals in a wireless communication system using beams. A BS may transmit, to a UE, information regarding one or more measurement gaps for measuring one or more reference signals. The BS may transmit, to the UE, additional information regarding at least one of direction information associated with the one or more reference signals or rank indication to be used by the UE to measure the one or more reference signals during the one or more measurement gaps. A UE may perform corresponding operations.

Abstract: Aspects of the present disclosure describe managing beams in wireless communications. A beam management event configuration indicating a type of at least one beam to measure in determining occurrence of a trigger condition for a beam management event can be received. A parameter of a signal received from one or more nodes can be measured, where the signal corresponds to the type of the at least one beam. The occurrence of the trigger condition for the beam management event can be determined based on the parameter of the signal. An indication of the occurrence of the trigger condition can be reported to the one or more nodes or a different node.

Abstract: Aspects of the present disclosure relate to receiver beamforming for serving and neighbor cell measurements. An exemplary method generally includes communicating with one or more base stations using a first beam type, initiating a transition to communicating with at least one of the one or more base stations using a second beam type in response to an indication of a trigger event, and communicating with the at least one of the one or more base stations using the second beam type.

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).