Precoding design for channel state information reporting

A communication apparatus, comprising a processor configured to;

• receive a reference signal from a transmitting device;
• determine a precoding matrix based on the reference signal, wherein a structure of the precoding matrix is based on one or more vectors, wherein the precoding matrix includes R columns, wherein a column of the precoding matrix is based on a weighted sum of a set of vectors corresponding to the column, wherein the set of vectors corresponding to the column includes partial or all of the one or more vectors;
• or one or two of the one or more vectors corresponds to one of R columns of the precoding matrix, R is equal to or greater than 1;
• and
• transmit information about the precoding matrix to the transmitting device,
• wherein one or more elements in a vector of the one or more vectors are zero.

A method for wireless communication, comprising:

• transmitting, by a transmitting device, a reference signal to a receiving device;
• and
• receiving, by the transmitting device from the receiving device, information about a precoding matrix corresponding to the reference signal, wherein a structure of the precoding matrix is based on one or more vectors,
• wherein the precoding matrix includes R columns, wherein a column of the precoding matrix is based on a weighted sum of a set of vectors corresponding to the column, wherein the set of vectors corresponding to the column includes partial or all of the one or more vectors;
• or one or two of the one or more vectors corresponds to one of R columns of the precoding matrix, R is equal to or greater than 1;
• and
• one or more elements in a vector of the one or more vectors are zero.