Abstract: Methods, systems, and devices for wireless communications are described. In some systems, a user equipment (UE) may measure a frequency selectivity of a channel between the UE and a base station and may transmit signaling to the base station indicating one or both of a frequency selectivity metric or a recommended demodulation reference signal (DMRS) port multiplexing pattern based on measuring the frequency selectivity. In some aspects, the UE may transmit the signaling to assist the base station in configuring a DMRS port multiplexing pattern based on current channel conditions. For example, if the frequency selectivity metric satisfies a threshold, the UE may recommend a DMRS port multiplexing pattern absent of code division multiplexing (CDM). Alternatively, if the frequency selectivity metric fails to satisfy the threshold, the UE may recommend a DMRS port multiplexing patter including CDM.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive, from a base station, a first tracking reference signal configuration and a second tracking reference signal configuration. The first tracking reference signal configuration may include a first set of parameters and the second tracking reference signal configuration may include a second set of parameters. The UE, the base station, or both may identify an indicator for selection from among the first tracking reference signal configuration and the second tracking reference signal configuration. The UE may receive, from the base station and based on the identified indicator for selection, a tracking reference signal in accordance with the first tracking reference signal configuration or the second tracking reference signal configuration.