Fuzzy MIMO detector for MC-CDMA systems with carrier frequency offset over multipath fading channels
Communication Research Center and Department of Communication Engineering, Yuan Ze University, Chungli, Taoyuan 32003, Taiwan
EURASIP Journal on Wireless Communications and Networking 2012, 2012:197 doi:10.1186/1687-1499-2012-197Published: 21 June 2012
A multistage fuzzy minimum output energy (MOE) detector is proposed for multiple input multiple output (MIMO) multi-carrier code-division-multiple access (MC-CDMA) uplink systems with carrier frequency offset (CFO) over multipath fading channels. The first stage of the receiver uses a novel MIMO receiver model with offset symbols to achieve a fuzzy CFO-constrained MOE detector that suppresses multiple access interference (MAI) and minimizes cancellation of the desired signal. To suppress noise and to enhance signal reception after the fuzzy MOE detector, a signal subspace projection and minimum mean square error weight combiner is proposed to enhance signal-to-interference-plus-noise ratio and bit error rate performances. Simulation results show that the proposed MIMO detector outperforms conventional MOE detectors and achieves the ideal receiver performance against MAI and CFO effects.