Research And Implementation On Parameters Estimation Algorithm Of Communication Signals Based On Cyclic-Spectrum

Radio monitoring plays an important role on radio frequency management and electronic countermeasure. And radio monitoring can implement the function of modulation recognition,parameters estimation and emitter location. Parameters estimation is the key technology of radio monitoring. Networking radio monitoring is the development trend of radio monitoring, as the basic unit of networking radio monitoring, the storing ability and anti noise ability of monitoring node are limited. Compared to the traditional power spectrum method, cyclic-spectrum is more comfortable for parameters extraction.Around the actual application requirement of networking radio monitoring, aiming at implementing the estimation of the carrier frequency and symbol rate of digital communication signals on the radio monitoring node, this paper has especially researched the estimation algorithms of the carrier frequency and symbol rate of 2ASK,BPSK,QPSK,8PSK,MSK and 16QAM signals based on cyclic-spectrum. The content of this paper is composed of the following four aspects:Firstly, according to the limitied-storing ability of the monitoring node, the frequency smoothing method of the cyclic-spectrum estimation has been researched. And the affcet of single f profile to paramenter estimation has been analyzed. this article provided a kind search algorithm based on neighbouring f profiles. In this way, the information of neighbouring f profiles of spectrally somoothed cyclic periodgram can be fully used.Secondly, the application of carrier frequency and symbol rate estimation based on the neighbouring f profiles search algorithm has been researched. According to the neighbouring f profiles search algorithm, the frequency estimation algorithm of 2ASK,BPSK and MSK signals and the symbol rate estimation algorithm of 2ASK,BPSK,QPSK,8PSK,MSK and 16QAM signals have been provided. Compared to single profile search algorithm, the simulation showed that the former could commendably improve the parameter estimation accuracy.Because the carrier frequency of MPSK( M≥4)signals can not be estimated through cyclic-spectrum f profile, the algorithm named square law cyclic-spectrum method for estimating the carrier frequency has been provided. Simulation results shows that it has better performance for improving the carrirer frquency estimation of MPSK signals( M≥4).Thirdly, according to the situation of the receiving signals almost being filtered by pulse shaping filter, the application of symbol rate estimation based on spectral-correlation function has been researched. The symbol rate estimation algorithm of 2ASK,BPSK,QPSK,8PSK,MSK and 16QAM signals has been worked out. Compared to symbol rate estimation algorithm based on cyclic-spectrum, the simulation showed that the latter owned better performance at low SNR, the former owned better performance when SNR met some condition.Finally, the implementation and debugging of all modules of parameter estimation on the hardware platform of radio monitoring node have been completed. The result showed that the modules of parameter estimation can commendably complete parameter estimation, further more the estimation precision can satisfy the requirement of the system.