SINR maximizing equalizer design for OFDM systems

A novel time domain equalizer (TEQ) design approach is proposed in this paper, based on maximizing the signal-to interference plus noise ratio (SINR). To increase the bandwidth efficiency of OFDM systems, the TEQ is used to mitigate the intersymbol interference (ISI) created by a channel with longer impulse response duration than that of the cyclic prefix (CP). The true ISI, ICI and noise parts of the signal at the output of the equalizer are formulated, based on the overall impulse response (OIR) (convolution of channel impulse response and equalizer impulse response). The SINR maximizing time-domain equalization (SMTE) method estimates the tap coefficients of the equalizer by maximizing the SINR of the signal at the output of the equalizer. Computer simulation and analytical results show that the performance of the SMTE method is superior to the performance of the much-used method of channel impulse response shortening (IRS).