58.74-Gbps 2x2 MIMO 60-GHz Optical/Wireless System with Simple Power-Detector Down-Conversion

We demonstrate a 58.74-Gb/s V-band orthogonal frequency-division multiplexing (OFDM) radio-over-fiber (RoF) system employing the 2 × 2 multiple-input-multiple-output (MIMO) technology and power detector for downconversion for the first time. Additional radio frequency (RF) tone is generated and transmitted from central station to replace the local oscillator at wireless receiver for power detector down-conversion. To enhance spectrum efficiency, the gap between OFDM signal and RF tone is not needed. However, the down-converted signal will suffer signal-to-signal beating interference (SSBI). In this letter, we propose and successfully employ the 2 × 2 MIMO SSBI mitigation schemes to mitigate SSBI, resulting in 45% capacity improvement.