An FPGA Implementation of MML-DFE for Spatially Multiplexed MIMO Systems

Although the maximum-likelihood decision-feedback equalization (ML-DFE) detection method for multi-input multi- output (MIMO) system leads to a good compromise between the performance and the complexity, the computational complexity of the ML part in the ML-DFE is still large. This paper describes a modified maximum-likelihood (MML) algorithm, which reduces the computational complexity of the original ML algorithm significantly without degrading the performance. Then, based on the MML algorithm, we propose the MML-DFE, which has the same performance as the ML-DFE but has much lower complexity. Both the ML-DFE block and MML-DFE block for 4times4 MIMO system have been implemented in field-programmable gate array to verify the functional correctness and the complexity advantage.