An Enhanced Transceiver Structure for Higher Performances in MIMO-OFDM Systems

This paper proposes an enhanced transceiver structure for higher performances in multiple-input multiple-output-orthogonal frequency division multiplexing systems. The proposed scheme has three modes for signal transmission and detection, and decides a scheme adaptively according to the wireless channel environment to efficiently solve main disadvantages for an already-developed path elimination QR decomposition-M algorithm (PEQRD-M). At low SNR, the proposed scheme uses hybrid space-time block code and spatial multiplexing scheme to solve one of the main disadvantages for the PEQRD-M which has poor error and throughput performances at low SNR for obtaining minimum target error performance. Furthermore, the proposed scheme uses hybrid PEQRD-M and lattice reduction-aided zero forcing (LR-aided ZF) to solve one of the main disadvantages for the PEQRD-M which has high complexity at low SNR. At high SNR, the proposed scheme uses the PEQRD-M for optimal signal detection with low complexity. The usage for the hybrid PEQRD-M and LR-aided ZF and the conventional PEQRD-M is decided by comparing normalized received SNR with threshold η per each subcarrier. In simulation results, various performance evaluations are shown for η = 0.3 and η = 0.7 using parameters of IEEE 802.11ac. Specifically, the proposed scheme has higher error and throughput performances with lower complexity than the conventional PEQRD-M according to the decreased value of threshold η.