A simple convergence comparison of Gallager codes under two message-passing schedules

The convergence rate of iterative decoding of Gallager codes on the additive white Gaussian noise (AWGN) channel using the sum-product algorithm (SPA) under the flooding schedule (FS) is compared with that under the turbo-decoding schedule (TDS). Analyses using extrinsic information transfer (EXIT) charts show that TDS exhibits a much faster convergence behavior than FS.