Linear and Non-Linear Detection for MIMO-OFDM Systems with Linear Precoding and Spatial Correlation

Precoding at the transmitter side facilitates the use of linear MIMO detection schemes, which are attractive for low-complexity receiver implementations. However, their performance remains sensitive to the impact of spatial correlation caused by mutual coupling between antenna elements and the spatial propagation conditions of the wireless channel. We discuss how to apply non-linear detection, which can help mitigating the impact of spatial correlation, in a closed-loop MIMO-OFDM system and compare the average rates achieved with both detection schemes. Results show that significant gains can be obtained in the high SNR regime and in a strong spatially correlated propagation environment by applying a non-linear detector while in the low to medium SNR regime a comparable performance is achieved with both detection schemes.