Transceiver Design for Spatial Multiplexing Based on Prewhitening Detector

Abstract

In this paper, we propose a joint-transmitter-and-receiver design for spatial multiplexing based on a novel prewhitening detector (PWD). By using decision feedback equalization (DFE), Gaussian approximation, a prewhitening filter, and a matched filter, the proposed PWD transforms the multiple-input-multiple-output (MIMO) system into several parallel single-input-single-output (SISO) schemes and facilitates single-symbol detection. The proposed scheme achieves near-optimal symbol recovery with a complexity similar to that of a minimum-mean-square-error decision feedback equalizer (MMSE-DFE). The closed-form symbol error rate (SER) of the PWD is derived, which can be used to closely predict the ML performance for uncoded V-BLAST schemes. By assuming full channel knowledge at the transmitter side, we use a preequalizer and a precoder in a downlink scenario. The preequalizer can transfer the feedback part of the DFE to the transmitter side and thus provide better performance in a low signal-to-noise ratio (SNR) with reduced receiver complexity. The precoder designed to minimize the SER of this system can further improve performance without affecting the complexity at the receiver side.