Generation of Spectrally Efficient Nyquist-WDM QPSK Signals using DSP Techniques at Transmitter

We investigate complexity and performance of transmitter DSP for Nyquist-WDM QPSK and show that filters with less than 20 taps can reduce the channel spacing to 1.1 times the symbol rate within a 1-dB penalty. OCIS codes: (060.1660) Coherent communications; (060.2360) Fiber optics links and subsystems