OFDM Vector Signal Generation Based on Optical Carrier Suppression

We propose a novel method to generate photonic quadrature-phase-shift-keying (QPSK) orthogonal frequency division multiplexing (OFDM) vector signal using only one Mach-Zehnder modulator, in which the OFDM signal is phase precoded and amplitude precoded according to the square-law characteristic of the photodetector. We theoretically analyze and experimentally demonstrate that this concept of the generation of the QPSK OFDM vector signal can be employed in our system architecture based on our proposed scheme. The results show that the bit-error ratios of the transmission system are less than the forward-error-correction threshold of 3.8 × 10^-3. By this scheme, we simplify the configuration and reduce the cost of the OFDM transmission system.