COMPARISON OF CHANNEL ESTIMATION AND EQUALIZATION TECHNIQUES FOR OFDM SYSTEMS
S. T, and S. N. Circuits and Systems: An International Journal (CSIJ)1 (1):
In OFDM (Orthogonal frequency division multiplexing) systems, channel estimation and channel equalization play a key role in overcoming distortions caused by phenomena like fading, delay spread and multipath effect. In
this paper, channel estimation and equalization techniques are analyzed to improve the performance of OFDM system. The channel estimation techniques considered here are estimation using wiener filter and frequency
domain approach. Prior Channel estimation leads to simple equalization. The channel equalization techniques employed here are based on LMS algorithm and one tap frequency domain equalization, under different channels;
AWGN, Rayleigh and Rician channels. Eye patterns for different channels are compared in simulation. It is observed from simulation that wiener filter provides better estimation and OFDM performance is better under
AWGN channel than fading channels. SER curves shows 6dB improvement in AWGN performance than fading channels to achieve 0.1 SER. In addition, MSE performance shows fast convergence for AWGN channel.