Methods, systems, and devices for wireless communications are described. A base station may determine the subcarrier spacing and carrier frequency used by a user equipment (UE) for communicating with the base station. The base station may select a sounding reference signal (SRS) configuration for the UE that is based on the subcarrier spacing and carrier frequency used by the UE. The SRS configuration may define the temporal spacing between repetitions of the SRS. The base station may indicate the SRS configuration to the UE so that the UE transmits repetitions of the SRS according to the SRS configuration. The base station may measure the SRS repetitions from the UE to determine the Doppler frequency for the uplink channel. The base station may use the uplink Doppler frequency to select a demodulation reference signal (DMRS) configuration for the UE.