Photonic generation of frequency-quadrupling millimeter-wave vector signal based on balanced detection without precoding

Photonic frequency-quadrupling millimeter-wave (mm-wave) vector signal generation is proposed by balanced detection without precoding. A dual-polarization quadrature phase shift keying (DP-QPSK) modulator is the main component of the scheme. In the DP-QPSK modulator, An optical carrier and ± 4st-order optical sidebands can be obtained in one QPSK modulator, while the other QPSK modulator driven by 16QAM baseband electrical I/Q data. After balanced detection, a 16QAM vector signal can be obtained by frequency-quadrupling. The proposed scheme can reduce the complexity of transmitter digital signal processing. By adjusting the sub modulators of the DP-QPSK modulator, a 4 Gbaud baseband 16QAM vector signal can be generated at 40 GHz by frequency-quadrupling. In addition, after 20 km single-mode fiber (SMF) transmission, the constellation, eye diagrams and the BER curves of the frequency-quadrupling mm-wave vector signal perform well.