Random access procedures
摘要
說明書
Beam management in a wireless network may comprise determination (e.g., at a base station, at a wireless device, etc.) of an uplink beam and/or a downlink beam. The wireless device and/or the base station may support beam correspondence (e.g., a downlink beam and an uplink beam have same/substantially similar channel characteristics, or are aligned/substantially aligned). The beam correspondence may enable a base station to determine a downlink beam based on measurements associated with uplink reference signals as determined by the base station. A downlink signal (e.g., DCI, PDCCH transmission, PDCCH order) may be used to trigger a transmission of an uplink reference signal from the wireless device. The downlink signal may be sent via a CORESET. A TCI state of the CORESET may indicate an uplink reference signal (e.g., an SRS) associated with an uplink beam. The wireless device may receive a PDCCH order via the CORESET with the TCI state indicating the uplink reference signal. The wireless device may send/transmit the uplink reference signal (e.g., via the uplink beam) to a base station, for example, based on receiving the PDCCH order. The uplink reference signal (e.g., as transmitted by the wireless device) may be measured at the base station for channel estimation and/or scheduling purposes. The base station may support beam correspondence and transmit downlink signals via a downlink beam determined/selected based on a measurement of the uplink reference signal at the base station.
