Performance Comparison of Haar Ofdm and Daubechies Ofdm in Presence of Carrier Frequency Offset (cfo) and Doppler Effect

Present day wireless communication systems demand for high data rates. Orthogonal frequency division multiplexing (OFDM) has emerged as a promising technology to provide these high data rates. OFDM is a digital modulation technique which divides the available spectrum into different sub bands. As a result data can be transmitted simultaneously using multiple subcarriers. Conventional OFDM is based on Fast Fourier transform. It uses Inverse Fast Fourier transform block at transmitter side and FFT block at the receiver side. Recent studies show that discrete wavelet transform can be used in the place of FFT as it provides better Bit Error rate performance. The major degradation factors that reduce the performance of conventional OFDM are Carrier frequency offset and Doppler Effect. This paper discusses the performance of DWT based OFDM in the presence of CFO and Doppler Effect. The paper compares the BER performance DWT OFDM using two wavelets, the Haar Wavelet and Daubechies wavelet. CFO and Doppler Effect are assumed to occur individually in the system. Simulations are carried out using MATLAB.