Claims:1. An apparatus of a user equipment (UE) configured for operation in a fifth-generation system (5GS), the UE comprising first and second array antennas for transmission of mmWave signals including a sounding-reference signal (SRS), the apparatus comprising: processing circuitry; and memory, wherein the processing circuitry is configured to:
in response to decoding radio-resource configuration (RRC) signalling that indicates antenna switching for SRS, initiate a countdown timer and transition the second array antenna from a low-power state to an active state;
decode a downlink control information (DCI) indicating SRS antenna switching;
if the DCI is not received while the countdown timer is active, generate a command to transition the second array antenna to a low-power state upon expiration of the countdown timer; and
if the DCI is received while the countdown timer is active (has not expired), configure the UE for transmission of the SRS by the second array antenna and reset the countdown timer;
if the DCI is received after expiration of the countdown timer, generate a command to transition the second array antenna from the low-power state to the active state and configure the UE for transmission of the SRS by the second active array antenna, and
wherein the memory is configured to store the DCI.
, Description:TECHNICAL FIELD

[0003] Embodiments pertain to wireless communications, and particularly to communications within Fifth Generation (5G) New Radio (NR) systems and networks. Some embodiments pertain to transmission of sounding reference signals (SRS) by user equipment (UE).

BACKGROUND

[0004] One issue with antenna switching is that a user equipment (UE) needs to prepare its second array antenna to be active while it waits for a downlink control information (DCI) from network for SRS transmission. However, if there is no DCI from the network or if the DCI is not received in a reasonable amount of time, the UE wastes excessive battery power keeping the second array antenna active.