OFDM的信号时域差分检测技术的应用

OFDM技术预计将成为第四代移动通信的主流技术。它的特点是各子载波相互正交,这样不但减少了子载波间的相互干扰,还大大提高了频谱利用率,而且该系统能够很好地对抗频率选择性衰落和窄带干扰。OFDM系统中二进制数据比特以PSK或QAM等调制方式调制到相应的子载波上。为了准确恢复信号,接收端需进行信号检测。时域差分检测通过比较当前OFDM符号子载波与前一个符号对应子载波的幅度和相位来实现。

The Application on the Time-domain Differential Signal Detection Technique of OFDM

It is predicted that OFDM technique will become the mainstream technique of the forth generation mobile communication system.Its characteristic that each subcarrier is orthogonal can not only reduce the interference between the subcarriers,but also improve the utilization ratio of the frequency spectrum.Meanwhile,the system can antagonize the frequency selective fading and the selective interference very well.The binary data bit of OFDM is modulated on the corresponding subcarrier by PSK or QAM.The receiving end is needed to detect the signal to restore the signal exactly.The time-domain differential signal detection technique is implemented by comparing the amplitude and the phase of the current OFDM sign subcarrier and the previous one.