Signal Model And Coherent Integration Methods In Passive Radar Based On Digital Television

Based on television, radio, telecommunications and other non-cooperative signals,the passive radar becomes a hot spot with its anti-low-level raid, counter-stealth andself-hiding ability. Now, with the popularity of digital television, the analog televisionwill face off the air. Because the digital television signal has a large bandwidth and it issteady, the research on the passive radar exploiting this kind of signal is of greatsignificance.At first, the development of the passive radar system and the digital televisionsystem are introduced. Next, structure traits and merits of terrestrial digital televisionbroadcasting are analyzed and the key techniques used in the passive radar based ondigital television are given out. Then orthogonal frequency division multiplexing(OFDM) technique is discussed. The theory and arithmetic of OFDM are derived andtwo OFDM signal models are set up with a carries modulation of quaternaryphase-shift keying (QPSK) and quadrature amplitude modulation (QAM). Thesimulation results show that it is all right for both of the two signals to be a transmitsignal for passive radars. At last, the migration compensation algorithms are proposed.An echo model of the moving targets in uniform velocity is present and a rangecompensation algorithm based on envelope interpolation is given. Moreover，an echomodel of the moving targets in uniform acceleration is set up, and an algorithm basedon fractional Fourier transform is pointed out. The modulation results show that thecompensation algorithms are efficient.