Performance Evaluation of Multi-Layered Space Frequency Time Codes for MIMO-OFDM Systems

In this paper, we study multi-layered concatenated coding for MIMO-OFDM systems. The proposed system combines spatial multiplexing with transmit diversity at each layer. In addition, each layer concatenates a powerful class of bandwidth efficient coding called IQ-TCM with STBC. This allows the code to achieve full spatial and frequency diversity for each layer at much lower complexity in terms of number of states without any bandwidth expansion. This paper evaluates the performance of serial and parallel interference nulling and cancellation algorithms with several ordering criteria. Furthermore, we demonstrate the advantage of multi-layered approach compared to V-BLAST and we show that the multi-layered system is much more power efficient over MIMO-OFDM channels.