Over-the-air (OTA) dynamic time division duplex (TDD) is disclosed with a channel use indicator (CUI) receiver (CUI-R) signal multiplexed in uplink transmissions. According to various aspects, a user equipment (UE) may receive a downlink grant from a serving base station, in which the downlink grant identifies downlink transmissions in one or more subsequent communication slots. The UE may identify a trigger for transmission of a channel usage signal associated with the grant that may be received by neighboring UEs that may potentially interfere. The UE transmits the channel usage signal in a next scheduled uplink region and then receives downlink data from the serving base station according to the downlink grant. If the neighboring UE receives a conditional uplink grant, then it may proceed with uplink transmissions when it fails to detect the channel usage signal from the UE.