Demodulation of 4×4 MIMO signal using single RF

Beam switching in the receiving antenna generates replicas in frequency domain, which enables MIMO decoding by using just single RF. It is fascinating to demodulate MIMO signals using single RF, which relieves the volume expansion by MIMO. However, this scheme has not been verified through a test-bed especially in 4×4 MIMO case. This paper presents test results of 4×4 MIMO receiver using single RF chain and beam switching antenna. Test results show the constellation and SNR of decoded 4×4 MIMO signal. When beam switching scheme applies, measured SNR was 12.95 dB on average and 17.85 dB at its maximum. This scheme can apply to massive MIMO system which requires quite a number of antennas and RF circuits.