More accurate performance analysis for BP decoding of LDPC codes using EXIT trajectories

By using extrinsic information transfer (EXIT) trajectories, we propose an improved performance-analysis method for belief propagation (BP) decoding of low-density parity-check (LDPC) codes. On the additive white Gaussian noise (AWGN) channel, the achieved convergence threshold values have errors to those computed by density evolution (DE) within 0.01 dB. Compared with those by EXIT charts, the threshold values obtained by the proposed EXIT-trajectory method are more accurate. Furthermore, we extend the method to the uncorrelated flat Rayleigh fading channel. In contrast with DE, the proposed method is more convenient since no computations for Fourier and inverse Fourier transforms are required during the analysis.