Research On The Correlation Techniques For HF Signal Wideband Detection And Sortation

With the development of communication technology, the number of the military and civiliantargets capable of high frequency (HF) communication is increasing, the communicationtechnology with low probability interception (LPI), such as burst and frequency hopping (FH)are widely used in HF communications, making HF communication electromagneticenvironment more complex. Meanwhile, the requirement of fast target reconnaissance and targetsituational awareness becomes more urgent. This paper is focused on correlation widebandreceived signal techniques such as modeling the HF channel, pre-processing techniques of signal,detection and sortation of LPI signal. The main works of this paper are as the following:1. The characteristics of HF communication are analyzed, the various complicated factors ofchannel environment are discussed. This paper establishes the HF wideband received signalmodel based on Watterson channel model, the colored noise background and all kinds ofinterference.2. Research on algorithm of pre-processing technology and detection of HF wideband receivedsignal is made. The binary method, mathematical morphology and its extended theory arediscussed. With regards to the practical problem of HF signal detection, an algorithm forwideband received signal detection is put forward based on the soft morphology pre-processing.The practical test shows the applicability of the method which improve the detection rate of HFwideband received signal.3. The correlation techniques for the detection of burst signal are discussed. The model forburst signal wideband detection is established. According to the analysis of burst signal, thispaper uses the wideband and narrowband detection method which obtains the occupied time rateusing the method of regulated morphology skeleton algorithm in order to confirm the presencedetection in wideband and improves the conventional detection algorithm both in time domainand frequency domain in order to extract the begin-end time in narrowband. The simulationresults indicated that the algorithm can achieve the burst signal detection and improve thebegin-end time precision.4. The model for FH signal wideband detection and sortation is established based on thededuction of the detection requirement and rules.This paper uses the time-frequency detectionalgorithm to confirm the presence detection based on the result of occupied time rate and granuleamount. Detection and sortation algorithm for specific hopping rate FH signal is proposed basedon mathematical morphology, identification of object and time-frequency matching method toeliminate interferes, sort signal and find deformity hop. The simulation results reveal the effective of the algorithm under complex channel environments.5. On the basis of the correlation theoretical research, HF signal wideband detection systembased on digital receiver is constructed, which achieves the basic function of signal detection, thepresence detection of burst signal and FH signal, multiple narrowband signals dispensation andnetwork transmission.