In wireless communication, the high rate and high quality of communication service are required to be offered. And OFDM has the advantage of the high bandwidth efficiency and strong anti-multipath ability, so OFDM receives widespread attention in recent years. OFDM is described as a multi-carrier transmission technique which discovered in mid-1960s, and use for in developing effective wireless data transfer. It is recognized as an effective transmission technique for high speed bi-directional wireless data transfer. And the main idea of OFDM is that the Channel will be divided into several sub channels orthogonal, and then turn High-speed data signals into parallel low-speed data-flow, modulation in each of the sub channels on transmission. Fast Fourier transform (FFT) algorithm and integrated circuit implementation modulator play an influential role towards effective OFDM amplitude spectrum modulation. The basic use of the OFDM include DAB (Digital Audio Broadcasting), WiMAX and so on.
The design constructs a complete OFDM system, and the basis property of OFDM. And the modulation or demodulation module can be achieved by IFFT and FFT respective. Add the Convolutional codes to improve the performance of the system. At last, by statistics the data, the curves of signal-to-noise ratio (SNR) - bit error in AWGN channel and Rayleigh channel is drawn.
Keyword：OFDM, Convolutional, Wireless communication
