Abstract: Methods, systems, and devices for wireless communications are described for estimating one or more environmental factors at a first user equipment (UE). The one or more environmental factors may be based on estimates of a Doppler spread and a power delay profile (PDP) taken over a set of subsets of a time period, based on multiple signals received from a second UE or a base station over the time period. The first UE may estimate the Doppler spread and PDP for a channel over each of the set of subsets of the time period, and may combine the Doppler spread over the set of subsets and combine the PDP over the set of subsets. The first UE may use the combined Doppler spread and the combined PDP to determine one or more communication parameters for the channel.

Abstract: The present disclosure involves determining base station (BS) beams for communicating between a UE and the BS. The BS may use sensor data or beam management reporting history to assist with determining one or more appropriate beams. The sensor data may include camera images, radar data, or lidar data, and be used to model the cell environment served by the BS. The BS may obtain reporting data from multiple UEs over time indicating the quality of beams received by the UEs at various locations in the cell environment and model the cell environment based on the reporting data. The BS may associate beams with possible UE locations within the cell environment and use the associations to determine beams for communicating with a UE after determining the UE's location.

Abstract: A method of wireless communications by a user equipment (UE) includes transmitting a wakeup message to awaken a base station from a sleep mode. The method also includes communicating with the base station after the base station awakens. A method of wireless communications by a base station includes entering a sleep mode when no user equipments (UEs) are connected to the base station. The method also includes receiving a signal from a UE to awaken from the sleep mode.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may identify combinations of modulation and coding schemes and resource block allocations that are associated with non-self-decodable codes. The UE may select a combination of a modulation and coding scheme and a resource block allocation based at least in part on the combinations of modulation and coding schemes and resource block allocations that are associated with non-self-decodable codes. The UE may transmit data over the physical channel in a communication generated using the selected combination of the modulation and coding scheme and the resource block allocation.

Abstract: Methods, systems, and devices for wireless communications are described. One or more UEs communicating over sidelink may indicate transmit and receive categories to other UEs. A first UE may receive, in a sidelink communication message, an indication of a receive category of a second wireless device. The first UE may then transmit a shared sidelink channel message to the second wireless device based on the receive category of the second wireless device. In another case, a first UE may receive, in a sidelink communication message, an indication of a transmit category of a second wireless device. The first wireless device may then compare the transmit category of the second wireless device with a receive category of the first wireless device. The first wireless device may determine whether to decode a shared sidelink channel message from the second UE based on the comparing.

Abstract: Aspects relate to mechanisms for a wireless communication device to select between a cyclic delay diversity mode and an antenna switch diversity mode for transmission of a signal based on at least one parameter associated with communication over a wireless channel. The parameter(s) may include a channel estimation parameter associated with the wireless channel, a communication parameter associated with at least one communication on the wireless channel, or a combination thereof.

Abstract: A transmitting device maps complex valued symbols in sequence to physical resource blocks for a sidelink transmission. The transmitting device reserves a first symbol of a subframe, where resource elements in the first symbol of the subframe are not considered in mapping the complex valued symbols to the physical resource blocks for the sidelink transmission. The transmitting device transmits the sidelink transmission after mapping the complex valued symbols to the physical resource blocks. A receiving device receives the sidelink transmission and decodes the sidelink transmission to determine complex valued symbols that are mapped in sequence to physical resource blocks of the sidelink transmission, where the complex valued symbols are not mapped to resource elements in a first symbol of a subframe.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may increase a transmission power for a physical sidelink shared channel (PSSCH) communication based at least in part on decreasing a transmission power for a physical sidelink control channel (PSCCH) communication. The UE may transmit the PSCCH communication using the decreased transmission power for the PSCCH communication and transmit the PSSCH communication using the increased transmission power for the PSSCH communication. Numerous other aspects are provided.