基于高阶累积量的OFDM信号调制识别技术

摘要

Due to its advantage of high spectrum utilization rate and low symbol interference, OFDM has a broad application in wireless communication systems. There is a wide demand for signal modulation identification and parameter estimation in electronic surveillance systems, military communication and interference identification. Thus the research of modulation identification of OFDM signal is the key point. Wtih the fact that the OFDM is asymptotical Gaussian, a detector based on high-order cummulants is proposed. Experiments show that this method has a good performance in the discrimination of OFDM from single cartier digital signals with less computation.%为解决非合作通信系统中OFDM（Orthogonal Frequency Division Multiplexing正交频分复用技术）信号的调制识别问题,提出一种基于四阶累积量的OFDM信号调制识别新方法。该方法利用OFDM信号时域包络具有渐近高斯性的特点,对已有基于累积量的识别方法进行改进,通过计算截获信号的复中频信号模值的四阶累积量,提取OFDM信号与单载波信号的分类特征量,对OFDM调制信号进行识别。该算法与已有的基于累积量的识别方法相比,计算量大大减小,且具有较好的识别效果。仿真实验表明SNR高于-2dB时,正确识别率大于99%,证明了该算法的有效性。