An improved stopping criterion for BICM-ID embedded turbo codes

This paper proposes an improved stopping criterion based on cross-entropy (CE) for BICM-ID embedded turbo codes. It can yield good BER performance with lower complexity. The iterative decoding scheme for turbo iterative receiver, which iterative number is fixed, can achieve good BER performance. The stopping criterion based on CE has been adopted to decrease the total iterative number. However, the calculations of CE in the traditional stopping criterion expend hardware resource too much. In order to reduce the complexity, this improved stopping criterion has been proposed: a minimum iterative number (Imin), which is determined by the SNR criterion, should be set first, after the iterative receiver activates for Imin times, the stopping criterion based on CE will be used for the rest numbers of iterations. Simulation results confirm that the iterative receiver with this novel stopping criterion scheme has achieved the similar performance with the fixed iterative number scheme but it is of a considerably reduced complexity due to the decreased iterative number of decoding and the fewer calculations of CE.