GSC-based equalizer with QR decomposition for CP-free MIMO-OFDM systems

Abstract

In CP(Cyclic Prefix)-Free OFDM systems, an occurrence of IBI(Inter-Block-Interference) is inevitable due to the loss of CP. Since it deteriorates the system performance, a GSC(Generalized Sidelobe Canceller)-based equalizer for SIMO(MIMO)-OFDM systems have been proposed. In the equalizer, a set of basis of null space of channel matrix has to be found. In this letter, we propose a GSC equalizer using QR decomposition for CP-Free MIMO-OFDM systems, where the reduced complexity maximum likelihood detection by QR M-algorithm(QRM-MLD) can be applied after the equalization. By computer simulations, we show the BER performance can be improved as compared to the conventional GSC equalizer with the V-BLAST detection.