Broadband transmission performance and antenna displacement tolerance in 4×4 short-range MIMO simple decoding

We previously proposed a simple decoding method for short-range multiple-input multiple-output (SR-MIMO) transmission that can reduce signal processing complexity by performing MIMO detection with an analog weighting circuit. In this paper, we evaluate the method's broadband transmission performance and antenna displacement tolerance by using a 4×4 SR-MIMO prototype system employing the method for quasi-millimeter wave band. We clarified that with the method broadband 16QAM transmission can be achieved with relative bandwidth up to 9% when transmitting and receiving array antennas are installed in the opposite position. We also clarified that broadband 16QAM transmission of 7% relative bandwidth can be achieved by installing the antennas with displacement of 0.08 wavelengths or less.