多载波OFDM信号识别方法

Recognition method of multi carrier OFDM signal

无人机(unmanned aerial vehicle, UAV)技术发展迅速,应用十分广泛,用作UAV测控数传的正交频分复用(orthogonal frequency division multiplexing, OFDM)信号,给民用无线频谱管理、军用非合作通信技术带来不小的挑战。基于此,提出了一种基于包络相关谱的OFDM信号检测识别算法。主要利用OFDM信号的时域相关性,通过计算信号的复包络相关谱,并检测判断其相关谱的离散周期性,实现了在非合作通信中OFDM信号的识别。相比基于高阶累积量的检测识别算法,所提算法具有更好的信噪比适应能力,而且不需要设定判别的经验阈值,同时还能估计出子信道的带宽。仿真实验结果验证了所提方法的有效性。

Unmanned aerial vehicle(UAV) technology has developed rapidly and is widely used. As the orthogonal frequency division multiplexing(DFDM) signal of UAV measurement and control data transmission, it brings great challenges to civil wireless spectrum management and military non cooperative communication technology. Based on this, an OFDM signal detection and recognition algorithm based on envelope correlation spectrum is proposed. The algorithm mainly uses the time-domain correlation of OFDM signal, calculates the complex envelope correlation spectrum of the signal, detects and judges the discrete periodicity of its correlation spectrum, and realizes the identification of OFDM signal in noncooperative communication. Compared with the detection and recognition algorithm based on high-order cumulant, the proposed algorithm has better adaptability to signal to noise ratio, does not need to set the empirical threshold, and can estimate the bandwidth of subchannel. Simulation results show the effectiveness of the proposed method.