OFDM信号中保护间隔样式的识别方法

摘要

There are a lot of methods with OFDM signals identification at present,among them only few methods focuses on the style of which filling in guard intervals.To solove the problem,this paper analysised the characteristics of the existing three kinds of guard interval and proposed a recognition method to the style in the fist time.The method defined a time-domain autocorrelation function,and identified the CP-OFDMby using the autocorrelation structure of cyclic prefix value.On the oth-er hand,it constructed a power self correlation function by a single symbol amplitude of the square,and choses the ratio of maximum and minimum value as the characteristic value to identifing the ZP-OFDMafter the wavelet denoising and reconstruc-tion.Finally,used the exclusive method to identify the TDS-OFDM.Simulation results show that,using this method has better recognition effect on OFDMsignal of three different guard intervals in the low SNR condition.%目前对 OFDM信号的识别研究已经有多种方法，但对其保护间隔采用何种填充样式的研究尚不多见。针对这类问题，通过分析现有三种保护间隔的特点，提出一种保护间隔样式的识别方法。该方法定义一个时域自相关函数，利用循环前缀的自相关性构造的特征值识别出 CP-OFDM。由单个符号幅度的平方值构造功率自相关函数，经过小波消噪与重构，选择最大值与最小值的比值作为特征值识别出 ZP-OFDM，利用排除法识别出TDS-OFDM。仿真实验表明，在较低的信噪比条件下，使用该方法对三种不同保护间隔的 OFDM信号均具有较好的识别效果。