OFDM系统接受和发送的matlab仿真及分析.pdf

EE326 wireless lab – 11/12 Chaoyun_Song OFDM baseband Transceiver Introduction In the broadband wireless communication system, the main influence of information transmission is the frequency selective interference. Because some of the frequency components have serious signal attenuation, however some other frequency components have higher gain. In order to overcome this kind of decline, a natural idea is divided in the channel more than one channel, make every is frequency characteristics of the channel are similar to flat, use these independent subcarrier to transimit signal and joint together in the receiver ending. In order to realize the signal frequency diversity, this is the basic idea of the carrier modulation. In the wireless communication the most widely used techique is the OFDM carrier modulation technology, all the subcarriers are orthogonal, and it improve the utilization rate of the spectrum. Meanwhile, add the cyclix prefix in OFDM symbols and use guard interval to transmit it. The OFDM symbol is cyclically extended in the GT, in order to prevent Inter-Channel Interference. The whole procedure of OFDM system is shown as: 1 EE326 wireless lab – 11/12 Chaoyun_Song Transmitter From the baseband output, there have a random bits signals. The length of the signal in this experiment is set as: bit per symbol*number of subcarrier*symbols per subcarrier