An Efficient Technique for OFDM System Using Discrete Wavelet Transform

With the rapid expand of wireless digital communications, demand for wireless systems that are reliable and have a high spectral efficiency have increased too. Orthogonal Frequency Division Multiplexing (OFDM) has been recognized for its good performance to achieve high data rates. Fast Fourier Transforms (FFT) has been used to produce the orthogonal sub-carriers. Due to the drawbacks of OFDM-FFT based system which are the high peak-to-average ratio (PAR) and the synchronization, many works have replaced the Fourier transform part by wavelet transform. In this paper, an efficient technique for the OFDM system using wavelet transform is proposed. This system shows a superior performance when compared with traditional OFDM-FFT systems through an Additive White Gaussian Noise (AWGN) channel. The system performance is described in Bit Error Rate (BER) as a function of Signal to Noise Ratio (SNR) and the peak-to-average ratio (PAR). Furthermore, the proposed system gives nearly a perfect reconstruction for the input signal in the presence of Gaussian noise.