Demultiplexing techniques of 320 Gb/s OTDM-DQPSK signals: A comparison by simulation

We present the demultiplexing and demodulation of 320 Gb/s OTDM-DQPSK signals using either `conventional', i.e. demultiplexing then detection, or coherent detections with the local oscillator operating in pulsed sequence. A continuous-wave local oscillator (LO) can be replaced by a short-pulse laser source in a homodyne coherent receiver enabling us simultaneously demultiplex and detect the multiplexed channels of the ultra-high speed OTDM phase modulated signals. Simulated results also indicate at least 5 dB improvement of the receiver sensitivity over the conventional technique by the pulsed LO coherent receiver.