An adaptive QR-based energy efficient signal detection scheme in MIMO-OFDM systems

Abstract

In this paper, an adaptive QR-based energy efficient low complexity signal detection scheme in multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) systems with nearly optimal error performance is proposed for solving the disadvantage of path elimination QR decomposition-M algorithm (PEQRD-M). For minimizing the loss of error performance, the proposed scheme uses suboptimal PEQRD- M, and hybrid PEQRD- M and lattice reduction-aided decision feedback equalizer (LR-aided DFE) adaptively by using channel state. The proposed scheme selects the signal detection scheme adaptively by calculating the condition number of wireless channel. The proposed scheme uses PEQRD- M when the channel state is poor where its condition number is high, and reversely uses the hybrid PEQRD-M and LR-aided DFE when the channel state is favorable where its condition number is low. The simulation results show that the proposed scheme has nearly the same error performance as PEQRD- M and low complexity at low signal to noise ratio (SNR).