Iterative interference cancellation and decoding for convolutional coded pre-transformed communication systems

In this paper, we propose a low complexity iterative interference cancellation and decoding (IICD) scheme for serial concatenated coded and pre-transformed communication systems. In this scheme, soft reliability information of the transmitted bits is exchanged between the maximum a posteriori (MAP) decoder and the detector employing interference cancellation (IC) technique. The complexity of the proposed scheme is only linear with respect to the size of the pre-transform and constellation set. This leads to significant reduction in computation complexity compared to conventional iterative detection and decoding (IDD), where the complexity is exponential with respect to the transform size and constellation size. We show that the proposed scheme can fully exploit the diversity of the fading channel and it reaches the BER bound of IDD at high SNR values after 3 to 4 iterations.