QR-RLS based Adaptive channel shortening IIR-TEQ for OFDM Wireless LAN

In this paper, QR-RLS based IIR adaptive channel TEQ(time domain equalizer) to make the OFDM systems robust for delay spreads exceeding the CP(cyclic prefix) is presented. IIR based TEQ results in much shorter length equalizer compared to FIR based TEQ, at the same time guarantee for global convergence within the training period. The length of zeros of the proposed QR-IIR TEQ is restricted to CP. Givens rotation based QRD updation of TEQ coefficients results in computational advantage. The performance of the proposed method is then compared with conventional LMS and QR-FIR TEQ in terms of convergence, computational complexity and BER. The simulation results show that proposed QR-IIR method gives better results as compared to the aforementioned methods.