The Blind Estimation Of The Parameters Of Continuous Phase Modulated Signals

With the rapid development of modern communication technology,thecharacteristic of the frequency spectrum and the bandwidth utilization of the signal areput forward more and more high demand.Continuous phase modulation(CPM) is anon-liner modulation signal with continuity phase,constant modulus,attractive spectraland power efficiency,which has been more and more used in communicationsystems.In electronic reconnaissance,the receiver can not learn any of the sendermodulation parameters.As to demodulate the correct information sequence in the caseof non-cooperative communication,the blind demodulation is needed.And the blindestimation of signal parameters is one of the most important research indemodulation.So in the electronic reconnaissance, the blind estimation of the CPMsignal parameters is a significant research.This paper consider the blind estimation problem of parameters such as carrierfrequency,code rate and modulation orde for the CPM signals.First focus on thefrequency spectrum characteristic and phase continuity of the MSK signal and thebinary CPM signals. Through a nonlinear transformation,methods are proposed toconvert the CPM signals into the FSK signals.And based on this,the blind estimation ofcarrier frequency and code rate are achieved.Second based on the deeply analysis ofthe separable line spectrum of the binary CPM signal when the modulation index is aninterger,discussed the characteristic of the separable line spectrum of the M-ary CPMsignal when the modulation index is an interger or non-interger.So a method toestimate the modulation order M has been proposed based on the separable linespectrum in the case of non-cooperative communication.