TR2015-039

Phase Noise-Robust LLR Calculation with Linear/Bilinear Transform for LDPC-Coded Coherent Communications



We propose a modified log-likelihood ratio (LLR) calculation for an LDPC decoder to be robust against residual phase noise at the demodulator. The proposed scheme is based on a linear/bilinear transform offers 1-2dB gain in the presence of large phase noise.