Methods and systems for line-of-sight (LOS) multiple-input and multiple-output (MIMO) communications with antenna misalignments

A sending device in a line-of-sight (LOS) wireless communication system, the sending device comprising:

• a receiver configured to receive feedback information from a receiving device that is external to the sending device, the feedback information comprising:
• estimated rotational angles between the receiving device and the sending device and an estimated translational distance between the receiving device and the sending device, or
• an offset angle between a first plane of antennas of the receiving device and a second plane of antennas of the sending device, a normal vector of the second plane of antennas and the estimated translational distance, wherein the estimated rotational angles between the receiving device and the sending device are determined based on a determination of multiple angle-of-arrival directions, a decomposition of a rotation matrix, or a direct estimation of the rotation matrix;
• and
• a processor configured to determine an optimal beamforming matrix for LOS communications between the sending device and the receiving device using the feedback information.

A method to determine an optimal beamforming matrix for line-of-sight (LOS) communications between a receiving device and a sending device in an LOS wireless communication system, the method comprising:

• determining at the receiving device a rotational estimate and a translational estimate of the receiving device with respect to the sending device;
• sending feedback information from the receiving device to the sending device, the feedback information comprising:
• estimated rotational angles between the receiving device and the sending device and an estimated translational distance between the receiving device and the sending device, or
• an offset angle between a first plane of antennas of the receiving device and a second plane of antennas of the sending device, a normal vector of the second plane of antennas and the estimated translational distance, wherein the estimated rotational angles between the receiving device and the sending device are determined based on a determination of multiple angle-of-arrival directions, a decomposition of a rotation matrix, or a direct estimation of the rotation matrix;
• and
• determining, at the sending device, the optimal beamforming matrix for LOS communications between the receiving device and the sending device.