Highly spectrum efficient OFDM/PDM wireless networks by using optical SSB modulation

Optical frequency division multiplexing (OFDM) wireless access network using optical single-sideband modulation is proposed, which allows to deliver different wireless signals from a central station to each base station over an optical fiber network. The optical single-sideband (SSB) OFDM can achieve the highest spectrum efficiency of 0.25 b/s/Hz. A 0.25 b/s/Hz has been experimentally verified by the error-free transport of two-channel 4.98 Gb/s BPSK signal on 10 GHz wireless carrier with the frequency channel interval of 20 GHz at 1550 nm over 50 km-long standard single-mode fiber link. Furthermore, it has been also experimentally confirmed that by introducing the polarization division multiplexing (PDM), the ultimate spectrum efficiency of 0.5 b/s/Hz can be achieved by the hybrid OFDM/PDM.