Digital-domain chromatic dispersion compensation for different pulse shapes: Practical considerations

We infer, by computer simulations, practical values of the overlap length for frequency-domain chromatic dispersion compensation in long and ultra-long-haul coherent optical systems. The overlap length has a direct impact on computational complexity and the receive-side DSP power consumption. The NRZ, RZ, and Nyquist-shaped signals are investigated. The presented results may be used as guidelines for trading off OSNR margin and computational complexity. In a sufficiently high OSNR scenario, these trade-offs may reduce computational complexity by 10-25%, depending on the particular filter implementation.