An apparatus for wireless communication at a UE is provided. The apparatus is configured to receive one or more pilot signals superimposed on a data signal from a network entity. The apparatus is further configured to receive an indication of a first set of locations in at least one of time or frequency from the network entity. The data signal or the scrambled data signal is near orthogonal to a channel estimation filter of the transmission channel between the network entity and the UE at the first set of locations. The apparatus is further configured to transmit characteristics of the transmission channel to the network entity. The characteristics of the transmission channel is determined based at least in part on the first set of locations.