Iterative MIMO detector using a group-wise approach

For multiple-input multiple-output (MIMO) systems, space-time bit-interleaved coded modulation (ST-BICM) using iterative detection has been recognized as a method for achieving near-capacity performance. However, the a posteriori probability detector required for the conventional ST-BICM receiver is not amenable to practical implementation for high-rate MIMO due to its exponential complexity in rate. This motivated the development of a single-stream detector exhibiting polynomial complexity and capable of delivering performance comparable to the conventional detector under near-ideal conditions. However, under realistic operating scenarios, with possibly low-rank channel conditions and/or employing fewer receive antennas than transmitted streams, the performance gap between the single-stream detector and the conventional detector widens. With a view to enabling practical implementations of high-rate near-capacity MIMO, we propose a novel detector based on a group-wise approach that can be flexibly configured to deliver the best possible combination of performance and complexity over a wide range of realistic operating conditions.