Research On Carrier Synchronization Technology In High Dynamic Environment

In recent years,the demand for communication receivers in high-dynamic environments has become more and more important with the rapid development of high-dynamic communication such as aeronautics,aerospace,navigation and remote sensing telemetry.Although low dynamic carrier synchronization technology is quite mature.But in the face of new challenges in high-dynamic environments,there are many new issues waiting for scholars to study in depth.For dynamic communication environments,the relative motion between the transceivers will cause Doppler effects and carrier frequency offset of the received signal,which seriously affects the reliable reception of signals.And the greater the dynamic range of this relative motion is,the greater the generated carrier frequency offset is,and there are even higher-order change rate shift,which bring great challenges to carrier synchronization.Therefore,it is of great practical significance to carry out research on carrier synchronization technology based on high-dynamic environments.1.Introduce the traditional carrier synchronization acquisition technology.Traditional capture algorithms can be divided into three categories: data-aided,non-data-aided and codeaided.This paper introduces its basic principles and derives the parameter estimation formula.Then,the typical data-aided algorithms such as Kay,Fitz and L&R are deduced and analyzed in detail.Finally,the frequency-mean-square error and computational complexity are simulated.2.Introduce carrier synchronization acquisition technology in high-dynamic environments.This paper introduces the current common method for estimating the fractional Fourier transform parameters of non-stationary signals with frequency-altering rate of change,analyzes the reason why it can be applied to carrier synchronization acquisition in high dynamic environment,and analyzes the basic process of parameter estimation.The shortcomings;then proposed based on the minimum mean square error of the parameter estimation method,the method uses the Taylor formula to approximate the phase representation,based on the minimum mean square error criterion,derivation of the carrier frequency deviation and frequency deviation rate of change estimated expression.Finally,the simulation analyzes the estimation error of the frequency deviation change rate under different frequency offset conditions and the estimation error of the frequency offset under different frequency deviation changing conditions based on the minimum mean square error criterion.Based on the simulation results,the capture conclusions are obtained.3.Introduced the traditional carrier synchronization tracking technology.This article describes a common phase-locked loop,the second-order phase-locked loop,Kalman filter algorithm.For phase-locked loop tracking methods,basic components of phase-locked loops such as phase detectors,loop filters,and voltage-controlled oscillators,and their basic principles and digital loop filter parameter design are introduced.For Kalman filter algorithms,The Kalman filter algorithm is introduced by the inadequacies of the digital loop filter,and its calculation principle is introduced.The extended Kalman filter algorithm is introduced for the nonlinear system,and the extended Kalman filter is used to predict and correct the carrier signal during tracking.The basic steps.Finally,the simulation gives the tracking error curve of the phase-locked loop to the signal,the acquisition of the joint minimum mean square error criterion and the BER curve of the phase-locked loop,and points out the insufficient tracking of the phase-locked loop.4.Introduce carrier synchronization tracking technology based on PSP technology in highdynamic environments.This paper proposes a tracking algorithm based on PSP for the problem of low tracking accuracy in high-dynamic environment.First introduced the basic principle of Viterbi demodulation and the design of the third-order phase-locked loop filter parameters.The coherent demodulation using the Viterbi algorithm contains multiple surviving path features in each symbol period,and is used in each surviving path.A thirdorder phase-locked loop is used to track the remaining carrier phase offset.Under the premise of sacrificing certain complexity,the tracking accuracy is greatly improved and the demodulation performance is improved.Finally,the simulation results show the tracking curves of the third-order PLL on the ramp-up frequency,the acquisition of the joint minimum mean-square error criterion,and the BER curve of the multi-phase-locked loop tracking based on the PSP technique,through traditional methods and theories.The comparison of the values proves the advanced nature of the proposed method.