说明：  Here, wavelets are used in Orthogonal frequency division multiplexing. Wavelets are small waves having amplitude increase starting zero and reduces back to zero. In conventional OFDM, IFFT is used at the transmitter side and FFT is used at receiver. In case of Wavelet OFDM, IFFT is replaced with IDWT and DWT is used instead of FFT. In OFDM cyclic prefix is added to reduce inter channel interference and inter carrier interference. By using wavelet transform, cyclic prefix is not needed. Hence, it has high spectral efficiency. Wavelet transform the signal one domain to time and frequency domain.