Linear precoding in mimo broadcast channel with arbitrary rank constraints

A transmitter, comprising:

• a precoder configured to iteratively generate an optimized precoder matrix and linear filters and further configured to precode an input stream using the optimized precoder matrix to produce transmission streams for a plurality of receivers, where at least one of the plurality of receivers has a plurality of associated transmission streams, the precoder comprising:
• a precoder update module configured to update the precoder matrix based on a linear filter from a previous iteration;
• and
• a filter update module configured to update the linear filters for the plurality receivers based on a precoder matrix from a previous iteration;
• and
• a plurality of antennas configured to transmit the transmission streams to the plurality of receivers.