Iterative multiuser detection for bit interleaved coded modulation

In this paper we present an approach for iterative decoding of bit interleaved coded modulation (BICM) in multi-transmitter multi-receiver scenarios. Conventional decoding methods yield results that are still way from the theoretical optimum. As a possible approach to achieve optimum performance multiuser detection via iterative cancellation is pursued. The main problem when applying this approach to BICM are cancellation errors, leading to a saturated performance. To overcome this behavior, soft-bits taking into account the reliability of the cancellation must be generated. We develop the optimum metric for this case. Using this metric we are able to approach optimum performance with few iterations. In a further step the metric is simplified yielding a complexity that is only fractions of the optimum approach.