The Jointly Gaussian Approach to Iterative Detection in MIMO Systems

This paper is concerned with signal estimation over general multiple-input-multiple-output (MIMO) channels based on a jointly Gaussian (JG) approach. We show that the proposed method is equivalent to the LMMSE approach, but is conceptually more concise and computationally more efficient. A 2×2 multi-antenna system with multipath effect is considered as an example to illustrate the advantages of the JG method. Also, a simple SNR-bounding evolution tool, similar to EXIT chart technique, is developed for fast assessment of the JG method. Compared with the optimal MAP algorithm, the JG method can achieve almost the same performance with greatly reduced complexity.