Effect of Doppler frequency and ber in FFT based OFDM system with Rayleigh fading channel

As the world moves to the future, there is a rising demand of high performance, high capacity and low Bit Error Rate(BER) in wireless communication, to integrate wide variety of communication services such as high-speed data, video and multimedia traffic as well as voice signals. Orthogonal Frequency Division Multiplexing(OFDM) is a multicarrier system that provides an efficient means to handle high-speed data streams over multipath fading environment. In this paper, we discuss the effect of Doppler frequency in Fast Fourier Transform(FFT) based OFDM system over Rayleigh fading channel. In this paper, multipath fading channel effect and the Bit error Rate (BER) on the performance of OFDM is shown where user´s mobility is taken into account. Quadrature Amplitude Modulation (QAM) scheme is used for BER with Rayleigh and Additive White Gaussian Noise(AWGN) channel. It will be implemented in MATLAB to acquire their BER performance and the result is compared.