Comparative analysis of BER performance of DWT based OFDM system with conventional FFT based OFDM system

As the world move in to the future, there is a rising demand for high performance, high capacity and high bit rate wireless communication systems to integrate wide variety of communication services such as high-speed data, video and multimedia traffic as well as voice signals. OFDM is a multicarrier system that provides an efficient means to handle high-speed data streams over a multipath fading environment. In this paper, comparison between the conventional FFT based OFDM systems with DWT based OFDM system have been made according to some conventional and non-conventional modulation methods over AWGN and Rayleigh fading channel. The different wavelet families have been used and compared with FFT based OFDM system and found that DWT based OFDM system is better than FFT based OFDM system with regards to the bit error rate (BER) performance, especially when it uses conventional modulation schemes and among all wavelet families, the bior5.5 wavelet family is better which give less error compare to others. The results presented in this paper are based on computer simulation performed using MATLAB software.