Line-of-Sight MIMO Transmission for Achieving High Capacity Fixed Point Microwave Radio Systems

Despite the lack of rich scattering which is necessary for MIMO systems in mobile environments, this paper proposes line-of-sight MIMO systems with the highest MIMO capacity in some tens of GHz microwave radios. The proposed scheme constructs spatially orthogonal MIMO channels by using geometric arrangement of antennas and can use individual local oscillator signals without feedback signals for a transmit matrix. It can also compensate for the fluctuation of the carrier phase caused by the geometric small shift of the antenna position.