Research On Identification And Parameter Estimation Of Phase Modulation Signals

In this paper, the recognition and parameter estimation of five phase modulation signals (BPSK、QPSK、Frank、P1、P2、P3、P4、LMF-BPSK and FSK-BPSK) which are in the field of electronicsurveilance were studied.First, the feature of phase and frequency of the phase modulation signals are studied in thedissertation. Through phase unwrapping, the instantaneous phase and instantaneous frequency can begot. On this basis, the recognition of five phase modulation signals can be achieved according to thetrip point of time-frequency curve、coefficient of kurtosis、fitting dispersion of time-phase curve,etc.Then a complete process of identification is put forward.A carrier frequency estimate algorithm of MPSK is proposed in this paper. On the basis offrequency-domain filtering, do the power operation, and turn MPSK to be NS. And then estimate thecarrier frequency of NS. On this basis, the methods of other parameter estimations were summarized,and put forward a decode algorithm. Finally, integrate the algorithms to a complete parameterestimation algorithm of MPSK.The blind parameter estimation method of LFM-BPSK is investigated in this paper. The square ofLFM-BPSK is used to eliminate the PN code, then turn it into LFM and estimate the initial frequencyand modulation factor of LFM, and then the estimation results are used as the initial values of thetwo-dimensional Newton iteration. On this basis, obtain the baseband signal and decode it by themethod similar as MPSK.In this paper, the blind parameter estimation method of FSK-BPSK is also studied. Segmentingthe signal by trip points and estimate the code element width of FSK. And then estimate parameters ofBPSK on each FSK code, finally form a complete parameter estimation algorithm.Matlab simulation shows that the proposed algorithms in this paper has high accuracy and lowcomputing complexity. All abrove proves that the algorithms can be applied to project.