Improved Layered Space Time Architecture Through Unequal Power Allocation and Multistage Decoding

In this paper, we investigate a new approach for improved performance of layered space-time (LST) codes based on unequal power allocation among layers combined with multistage decoding (MSD). LST architecture achieves high transmission rate for multiple-input multiple-output (MIMO) wireless communication systems with moderate complexity through separate multi-user detection and decoding at the receiver. An improved scheme presented in this paper is to employ MSD at the receiver. Such an LST scheme with MSD effectively applies the idea of multi-level coding (MLC), which, based on information chain rule, is capacity achieving. With an MSD receiver, we propose to apply different transmit power among layers, so that they would have the same error performance. As such, the overall error performance is optimized. Simulation results demonstrate that the proposed scheme significantly outperforms conventional LST schemes, without increasing computational complexity