Patent attributes
Methods, systems, and devices for wireless communications are described. One example includes calculating one or more first channel capacities for each precoder hypothesis of a first subset of precoder hypotheses and selecting a first precoder hypothesis of the first subset of precoder hypotheses using the calculated first channel capacities. The example also includes selecting a second subset of precoder hypotheses based on the first precoder hypothesis, calculating one or more second channel capacities for each precoder hypothesis of the second subset of precoder hypotheses, and selecting a second precoder hypothesis of the second subset of precoder hypotheses using the calculated second channel capacities. The example also includes selecting grouping co-phase factors based at least in part on the first precoder hypothesis or the second precoder hypothesis and transmitting a first precoding matrix indicator that indicates a first precoder index based on the one or more grouping co-phase factors.