Performance Analysis and Multi-Stage Iterative Receiver Design for Concatenated Space- Frequency Block Coding Schemes

This paper presents performance analysis and computationally efficient receiver design for concatenated space-frequency block coded orthogonal frequency division multiplexing (SFBC-OFDM) systems. Firstly, we present a simple method to approximate the theoretical bit error rate performance of the optimal maximum likelihood (ML) receiver for concatenated SFBC-OFDM systems. Next, we propose a low complexity multistage iterative QR decomposition based successive interference cancellation (QR-SIC) detector for OFDM systems employing the concatenated SFBC strategy. The proposed detector utilizes a Turbo-like iterative QR-SIC algorithm that exploits both spatial and frequency diversities inherent in multi-input multioutput (MIMO) multi-path fading channels. The performance of the proposed QR-SIC receiver is evaluated via Monte Carlo simulations. Our results show that the performance of the proposed receiver can approach the theoretical BER performance of the optimal ML receiver at high signal-to-noise ratios. In addition, we also compare the performance and complexity of the proposed QR-SIC detector with a Turbo-based maximum aposteriori (MAP) demodulator. These comparisons show that the proposed QR-SIC scheme performs reasonably well with respect to the MAP demodulator at higher iterations while attaining a much lower complexity than the MAP demodulator.