Research On The Multi-beam Coherent Integration In Digital TV Based Passive Radar

The passive radar uses the signal which emitted by the non-cooperativetransmitter for target detection and location. It has the inherent advantages to resist thethreats which modern radar are facing. At the same time, the high stability and widebandwidth makes the digital television signal to be the most ideal reference signal ofthe passive radar.The main contents of this paper are a series discussion of coherent accumulationin the digital television passive radar. We carefully analyzed and discussed the fastcomputation algorithm of cross ambiguity function(CAF) based on frequency domainpulse compression, the fast computation algorithm of multi-beams CAF, the migrationcompensation algorithm based on velocity channel division, and we gave a completeCAF real-time processing design. The research results of this paper are important andcan be used in digital TV passive radar system directly. The main content covers thefollowing aspects:In chapter1, we introduced the research background and significance, gave themodel of the passive radar system, and explained some problems in coherentintegration processing of passive radar system.In chapter2, we introduced the signal processing procedure of the conventionalPD radar, then we introduced the fast computation algorithm of CAF based onfrequency domain pulse compression. Through the analysis of the periodic side peakinterference in time domain, we put forward the suppression method. From the viewof computation cost, we compared the performance of the new fast computationalgorithm of CAF based on frequency domain pulse compression and the classical fastcomputation algorithm of CAF based on CIC+FIR. Finally, a preliminary design offast computation algorithm of CAF based on frequency domain pulse compression isgiven.In chapter3, we introduced the digital beam forming (DBF) technology, thendescribed the principle of the multi-beams CAF algorithm. By the limitation of thescale and speed of the current FPGA chips, the fast computation algorithm of CAFneed to adapt and improve in real-time realization. When the signal is processed in segmentation, the edge effect of the filter will cause periodic side peak interference infrequency domain. We adopt the method by padding the filter to solve the problem. Inorder to improve the computational efficiency of the whole real-time processingsystem, we need reasonable DDR control strategy. According to the specificrequirements in engineering implementation, we introduced the control method ofseveral groups of DDR in details. Finally, we gave the hardware platform and the testplan of the real-time processing system, the processing results of the real data showthe effectiveness of the system.In chapter4, through the establishment of the mathematical model of passiveradar system and moving target, we described the moving target migration problem inquantitative at long-time coherent integration processing. In order to reduce the targetmigration influence on target detection SNR, we proposed the range migrationcompensation algorithm based on velocity channel division. Based on theimplementation of multi-beams CAF algorithm in chapter3, we controlled the secondgroups of DDR flexibly to realize the range migration compensation algorithm. Theprocessing results of the real data on the hardware platform verify the validity of thealgorithm.Finally, the work in this paper is systematically summarized, and the direction offuture work is prospected. At the same time, the author says thank you to those peoplewho have made contributions for this paper.