Performance comparison of parallel concatenated codes using EXIT chart prediction

We study two different parallel concatenated coding schemes by way of EXIT chart prediction. One scheme is the famous turbo code, while the other is a concatenation of regular LDPC codes. Both schemes can be decoded by soft-in/soft-out decoders in an iterative fashion, which makes them attractive for usage in modern communication systems. In these iterations extrinsic information is exchanged between decoder stages, enabling us to use the EXIT chart theory based on extrinsic information transfer. We use a simplified simulation setup to obtain the EXIT characteristics for the constituent encoders and apply the results to the parallel concatenated codes. The performance of these coding schemes is evaluated by predicting Cliff E/sub b//N/sub o/, residual bit error rate, and decoder complexity beyond the Cliff E/sub b//N/sub o/.