ofdm仿真，用matlab仿真实现ofdm，为初学者提供一条道路(The proposed secret data embedding and extraction in
OFDM is shown in figure 1.In order to achieve higher data
rate, the serial data stream bits are converted in to parallel data
output bits. Then the modulation schemes can be BPSK,
QPSK or QAM, which in turn assigns the complex data
points. The orthogonality between subcarriers is maintained
by IFFT and FFT pairs which also transforms frequency
domain components to time domain and vice versa. 64 point
IFFT is used in this methodology.)