Orthogonal Frequency Division Multiplexing Vector Millimeter-Wave Generation Based on Two Parallel Phase Modulators

We propose an implementation scheme for generating orthogonal frequency division multiplexing (OFDM) vector millimeter-wave (mm-wave) based on two parallel phase modulators (PMs). Compared with previous schemes, the proposed scheme only needs two PMs without complex circuits to control the direct current bias of the modulator and precoding technology, which greatly reduces the complexity of the transmitter and the system cost. The OFDM vector signal and radio frequency (RF) signal arc generated by digital signal processing (DSP) module to ensure the flexible adjustment of RF signal frequency. In the DSP module, one up-converted OFDM vector signal and the unmodulated radio frequency signal arc transformed by Hilbert transform to obtain the dual single sideband (SSB) signals, respectively, which drive phase modulators. An optical interleaver is used to filter out optical carriers, and a high-speed photodetector is used to obtain the OFDM vector mm-wave signal through beat frequency. Based on the proposed scheme, we demonstrate the generation of a 50-GHz quadrature phase-shift keying (QPSK)-modulated OFDM vector mm-wave signal by simulation with the MATLAB and the optical communication commercial software. The measured results versus received optical power and phase deviation drift arc analyzed. The results show that the bit error rate of the transmission system is less than the hard decision forward error correction threshold of 3.8 x 10(-3), which shows that the scheme of OFDM vector mm-wave signal generation is feasible.