Precoder matrix indication and codebook structure for precoding for frequency selective MIMO channels

A communication device for performing in a wireless communication system a transmission to a network entity, like a base station or another communication device of the wireless communication system. The communication device receives from the network entity of the wireless communication system a precoding matrix indicator indicating a precoder matrix for one or more transmission layers and transmission resources, like time domain resources and/or frequency-domain resources, of a transmission channel (PUSCH, PSSCH) to the network entity. The communication device includes a precoder, wherein the precoder is to precode, responsive to the received precoding matrix indicator, time domain resources and/or frequency-domain resources of the transmission channel (PUSCH, PSSCH) to the network entity over one or more ports of the communication device. The communication device performs the transmission to the network entity using the precoded time domain resources and/or frequency-domain resources of the transmission channel (PUSCH, PSSCH) over the one or more ports. The precoder is based on one or more codebooks and a plurality of combining coefficients for complex combining components from the one or more codebooks, the one or more codebooks including one or more of:BL a spatial codebook comprising one or more spatial beam or port selection components of the precoder, and/orBL a delay codebook comprising one or more delay components of the precoder, and/orBL a Doppler-frequency codebook comprising one or more Doppler-frequency components of the precoder.