Multi-beam selection for beamformed multiple input multiple output wireless communications

An apparatus for wireless communication, comprising:

• a processor,
• memory coupled with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the apparatus to:
• measure, at a second wireless device, a channel quality of a plurality of reference signals that are transmitted by a first wireless device using a plurality of combinations of analog beamforming parameters for two or more beams that carry two or more multiple-input multiple-output streams, wherein the plurality of reference signals are transmitted for different combinations of one or more sets of transmit beamforming parameters and one or more sets of receive beamforming parameters;
• select a first combination of analog beamforming parameters based at least in part on the measured channel quality of the plurality of reference signals;
• and
• communicate with the first wireless device via the two or more beams based at least in part on the first combination of analog beamforming parameters.

An apparatus for wireless communication, comprising:

• a processor,
• memory coupled with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the apparatus to:
• receive, at a first wireless device, a plurality of reference signals that are transmitted by a second wireless device using a plurality of combinations of analog beamforming parameters for two or more beams that carry two or more multiple-input multiple-output streams;
• determine a set of analog beamforming parameters for the two or more beams based at least in part on measurements of the plurality of reference signals;
• determine a set of transmission baseband precoder parameters to be applied to baseband signals of the two or more beams based at least in part on a channel estimation of a channel between the first wireless device and the second wireless device;
• determine a set of receive baseband combiner parameters to be applied to baseband signals of the two or more beams based at least in part on the channel estimation;
• and
• communicate with the second wireless device using the two or more beams based at least in part on the set of analog beamforming parameters, the set of transmission baseband precoder parameters, and the set of receive baseband combiner parameters.

A method for wireless communication, comprising:

• transmitting, from a first wireless device, a plurality of reference signals to a second wireless device using a plurality of combinations of analog beamforming parameters associated with two or more beams that are configured to carry two or more multiple-input multiple-output streams, wherein the plurality of reference signals are transmitted for different combinations of one or more sets of transmit beamforming parameters and one or more sets of receive beamforming parameters;
• receiving, from the second wireless device, a report that indicates a first combination of analog beamforming parameters is selected for the analog beamforming parameters at the second wireless device;
• and
• communicating with the second wireless device via the two or more beams based at least in part on the first combination of analog beamforming parameters.