Target Signal Detection Based On Broadband Signal Channelization

Electronic reconnaissance plays an important role in modern warfare,providing an important reference for electronic offense and electronic protection is an important way to obtain military intelligence.Modern electronic warfare uses a variety of advanced electronic devices,with a variety of communication methods,and the signals transmitted on the battlefield are more complicated.In the severe battlefield electromagnetic environment,electronic reconnaissance receivers generally have large bandwidth and dynamic range in order to achieve full probability signal interception.However,how to detect narrow-band target communication signals in the intercepted wide-band signals is an urgent problem to be solved in the field of electronic reconnaissance.The short-wave and ultra-short wave bands are the main battlefields of electronic warfare and the main frequency bands for electronic reconnaissance.Therefore,the main goal of this paper is to effectively detect a specific narrow-band target signal in the wideband signal intercepted by the ultrashort wave band.According to the known information,the target signal is an enemy communication signal conforming to a certain military standard.The main research content of this paper includes the following two parts:The first part mainly studies the basic theory of channelization technology.Firstly,this paper studies the sampling theorem of signals,introduces the structural models of several receivers,and analyzes the theory of multi-rate signal processing,and deduces the multiphase representation of the filters.Then,starting from the channelization filter bank,we first introduce the basic concept of the filter bank,study the channelization method of the bandpass filter bank,analyze the structure of the low-pass implementation of the filter bank,and study the filtering.The high-efficiency structure of the device group discusses the channelization implementation of the real signal and the complex signal based on the polyphase filter bank.Finally,a wideband reconnaissance signal with a frequency range of 68-78 MHz is simulated.The high-rate wideband signal is split into 100 low-rate sub-channel signals with a bandwidth of 100 KHz through polyphase filtering digital channelization,and the low-pass prototype filter is analyzed.The effect of the design on the channelized subchannel signal.The second part mainly studies the signal detection algorithm.First,the basic ideas of several conventional detection methods are studied,and their respective advantages and disadvantages are analyzed.Then,for the detection of target signals in the channelized subband,the sub-band average energy adaptive threshold detection method is introduced,the structure block diagram of the method is described,and the frequency domain implementation of the correlation function calculation is deduced.On this basis,we propose a detection method based on the peak ratio of the correlation function.Next,the sub-band average energy adaptive threshold algorithm and the correlation function peak ratio algorithm are simulated respectively,and the performance of the two detection methods is analyzed.Finally,some dimensionless features of the correlation function are studied,and the signal and noise are classified by SVM classifier according to the extracted features.