在有保护间隔的情况下，系统通过调制解调实现ofdm信号的接收。对比比较了有保护间隔下和无保护间隔下误码性能的区别，更好的体现了ofdm系统的价值-Ofdm signal reception in the guard interval, the system via modem.Contrast compared the difference between the BER performance of the guard interval and unprotected intervals, better reflect the value of ofdm system