Dispersion Compensation FIR Filter With Improved Robustness to Coefficient Quantization Errors

In this paper, we propose a new finite impulse response (FIR) filter for chromatic dispersion compensation which is given in closed form. We identify a relation between the out-of-band gain and the in-band error when the filter is implemented with finite-precision arithmetic. In particular, a large out-of-band gain makes the filter more sensitive to coefficient quantization errors due to finite precision digital signal processing. To improve robustness to coefficient quantization errors, our proposed filter is designed based on confining the out-of-band gain. By means of simulations, we show that our filter outperforms other existing FIR filters. The performance gain improves with increasing modulation order and decreasing number of bits used to represent the filter taps.