Aspects provide for selecting a precoder mode for a transmission, changing a cyclic prefix (CP) length based on the selected precoder mode, and transmitting a signal that includes the changed CP length. Changing the CP length may involve using the selected precoder mode to lookup a value by which to change a nominal CP length. After changing the CP length, information indicating the changed CP length may be transmitted to a receiver of the signal. Precoder mode selection may be based on feedback information that indicates whether a receiver requests a change to the CP length. Precoder mode selection may be based on a received reference signal that indicates a condition of a communication channel. The reference signal may be used to select the precoder mode that results in the smallest relative delay spread, the largest relative delay spread compression, the largest relative beamforming gain, and/or the largest relative throughout.