Study On Key Algorithms Of Signal Processing In Electronic Reconnaissance And Subsampling Wideband Digital Receiver

Electronic reconnaissance is an important field in the electronic warfare, and its main role is to reconnoitre signals from the enemy radar. Nowadays, the hardware platform of the wideband digital receiver for electronic reconnaissance is increasingly common, so its performance is determined by the signal processing algorithm equipped by the receiver. In this paper, key algorithms of electronic reconnaissance signal processing and the subsampling wideband digital receiver of electronic reconnaissance are researched, combining with the hardware characteristic of the wideband digital receiver. The innovative achievements in this paper are:(1) A fast and arbitrary frequency estimation algorithm for sinusoid signal is proposed, which solves the realization problem of frequency estimation algorithm for sinusoid signal of any length in digital signal processors. The estimation accuration of this algorithm is better than that of M-Rife algorithm. The computational complexity is small, and it is easy to be realized real-timely in DSP and other hardwares.(2) A fast and accurate recursive algorithm for frequency estimation of sinusoid signal is investigated, which solves the realization problem of frequency estimation algorithm for sinusoid signal of large length in digital signal processors. The estimation accuration of this algorithm is nearly the same as that of the M-Rife algorithm. The computational complexity is small, and it is easy to be realized real-timely in DSP and other hardwares.(3) The initial values of the Newton's method for parameters estimation of the linear frequency modulation(LFM) signal is investigated. The DPT algorithm is used to get the parameters estimation of LFM signal, and then the estimation results are used as the initial values of the the Newton's method. Analysis show that when the signal to noise ratio(SNR) is lager than the SNR threshold of the DPT algorithm, the interative will never be non-convergent. The simulation results show that the estimation accuracy of parameters can reach cramer rao bound(CRB). The computational complexity is small, and it is easy to be realized real-timely in DSP and other hardwares.(4) A new blind carrier frequency estimation algorithm of the binary phase-shift-keying(BPSK) signal is proposed. And based on this algorithm, a complete decoding method of the BPSK signal is obtained. Using this method, the BPSK signal can be decoded without any prior kownledge. And the correct rate of decoding can be still high even in low SNR.(5) A signal processing algorithm is proposed, which is based on the data sampled by two ADs of different sampling rates. The frequency ambiguity can be resolved, and the multi-signal can be metched in the sub-sampling condition. And with FPGA, this algorithm is realized to deal with two signals arriving at the same time with the processing bandwidth 960MHz. And the design idea can be extended to deal with more than three signals arriving at the same time. So a new way is explored to deal with multi-signals arriving simultaneously using this design idea.