对仿真信号进行复morlet小波变换后，绘制的时频图。-After the simulated signal multiplexing morlet wavelet transform, time-frequency diagram drawn.

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.