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

Abstract

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 $\eta $ per each subcarrier. In simulation results, various performance evaluations are shown for $\eta = 0.3$ and $\eta = 0.7$ 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 $\eta $ .