基于混合OFDM的矿井下通信信号调制识别  

Modulation Recognition of Underground Communication Signals based on Mixed OFDM

作　　者：魏瑾[1] WEI Jin(Shanxi Institute of Mechanical and Electrical Engineering,Changzhi Shanxi 046011,China)

机构地区：[1]山西机电职业技术学院,山西长治046011

出　　处：《通信技术》2021年第3期550-556,共7页Communications Technology

摘　　要：当前矿井下通信信号调制识别方法忽略了获取信号包络剩余概率分布和信号噪声的抑制,无法获取通信信号正确序列,导致识别效率低、误差大且通信信号白噪声较高,因此提出基于混合正交频分复用技术(Orthogonal Frequency Division Multiplexing,OFDM)的矿井下通信信号调制识别方法。以井下宽阔地带、井下构造复杂地区以及井下狭窄地区为主要通信环境,分别获取几种情况下的多径信号包络对应的密度函数,分析其分布特征,得到接收信号包络的剩余概率分布,由此证明矿井通信信号为OFDM信号序列。在子载波组的基础上获得接收信号的序列,并消除其循环前缀,并基于此调制码元序列获取信号合并器中的输出信号,提取高阶累积量,消除信道衰落噪声。通过欧式距离分类方法,根据获取的信号特征向量进行分类,利用建立矿井下通信信号调制方式的判决准则,完成基于混合OFDM的矿井下通信信号调制识别。为验证所提方法的有效性,设计了仿真实验。实验结果表明,与传统方法对比,所提方法的通信信号调制识别耗时更短、正确率更高,并能够有效抑制通信信号噪声,可为相关领域研究提供有力支撑。The current mine communication signal modulation recognition method ignores the acquisition of signal envelope residual probability distribution and the suppression of signal noise,so it cannot obtain the correct sequence of communication signal,resulting in low recognition efficiency,large error and high white noise of communication signal.Based on Orthogonal Frequency Division Multiplexing(Orthogonal Frequency Division Multiplexing),a method for modulation and recognition of communication signals in underground mines is proposed.Taking open areas,urban areas and rural areas as the communication environment,the density functions corresponding to the multi-path signal envelope under several conditions are obtained respectively,and their distribution characteristics are analyzed to obtain the residual probability distribution of the received signal envelope.Thus,it can be proved that the mine communication signal is OFDM signal sequence.The sequence of the received signal is obtained on the basis of the subcarrier group and the cyclic prefix is eliminated.Based on this modulation code sequence,the output signal in the signal combiner isacquired,the high-order cumulant is extracted,and the fading noise of the channel is eliminated.Through the Euclidean distance classification method,the signal feature vector is obtained and classified,and the modulation recognition of mine communication signal based on mixed OFDM is completed according to the decision criterion of setting up the modulation mode of mine communication signal.In order to verify the effectiveness of the proposed method,a simulation experiment is designed.The experimental results indicate that compared with the traditional method,the proposed method takes less time to modulate and identify the communication signal,has a higher accuracy rate,and can effectively suppress the communication signal noise,providing strong support for the research in related fields.

关 键 词：混合OFDM 无线通信技术 矿井下通信信号 调制识别 

分 类 号：TN911.72[电子电信—通信与信息系统]