Analysis and design of natural and threaded space-time codes with iterative decoding

We consider code design of threaded and natural space-time codes and analyze their performance. We show by a counter example that, for these codes, even if the binary rank criterion is not satisfied, they demonstrate full diversity performance in the region of interest when iterative decoding is used. Hence, the relevant parameter for efficient code design is not the rank diversity. We conjecture that this parameter is the block-diversity. We provide simulation results, and, in order to reinforce our conjecture, we analyze the behavior of the iterative interference cancellation decoder by using density evolution with the Gaussian approximation.