NLFM-DSS signal acquisition method based on DPT and PMF-FFT

For the problem of acquisition of high dynamic NLFM-DSS (nonlinear frequency modulation direct spread spectrum) signal, a kind of new method is presented, which is based on Discrete Polynomial-phase Transform (DPT) and PMF-FFT. In this algorithm, the high-order phase coefficient of Polynomial Phase Signal (PPS) is estimated by DPT, so that the high-order phase term can be removed. Using this method, the NLFM-DSS signal can be transformed into new PN code multiplied by sine and new noise. That is direct sequence spread spectrum (DSSS) signal with the residual carrier frequency offset. And then, using algorithm based on partial correlation and Unrelated cumulation of power spectral to capture the signal. This paper presents the algorithm based on the signal model and the analytical expression, and through the use of computer simulation to verify the feasibility of the method.