Research And Implementation Of Synchronization Technology For High-speed Multi-h CPM Signals Under Large-dynamic Condition

With the development of telemetry technology of new launch vehicles and guided missiles,the rate of data information increases continually,which causes concern for frequency efficiency of signal modulation.The high efficiency Modulation system based on Multi-h Continuous Phase Modulation(Multi-h CPM)can well adapt to the nonlinear channel transmission with limited bandwidth and power.In addition,the system adopts the low-complexity MLSE detection,modulation parameters optimization,TPC/LDPC channel coding technology,which can manage complex communication environment with rapid changing and solve the stability of reception of high-bit-rate signals under large-dynamic conditions.The modulation of multi-h CPM will improve the system spectrum efficiency and power efficiency,and effectively improve the competitiveness in fields of heavy-lift carrier rocket,new missiles and space-based satellite multiple access control in the future.Our research task raises from the above background,in order to complete stable and reliable signal receiving and demodulation of high-bit-rate Multi-h CPM signals under large-dynamic conditons,We have to conduct further theoretical research and technological breakthroughs of timing and frequency synchronization technology for high-bit-rate Multi-h CPM signal.So that the goal of reducing the complexity of the synchronization module and achieving fast accurate signal capture can be realized,which is one of the most important and difficult part in the process of developing Multi-h CPM telemetering receiver.The synchronization of Multi-h CPM signal mainly involves two aspects: one is the symbol timing estimation,namely timing synchronization problems,which aims at realize alignment of receiving signal and local signal at high-bit-rate and correct demodulation of signal element.That need both fast timing circuits work ability and higher requirements of the error adjustment accuracy.Another is carrier frequency and phase synchronization.As multi-h CPM is a modulation technology with memory,high efficiency and constant envelope,whose modulation information focuses on the phase,which makes itself the most important and difficult part of the receiver synchronization technology.In the case of large doppler frequency shift,it is necessary to use the frequency offset estimation technology to correct the larger frequency shift at the earlier stage,and then use the decision-directed phase loop to track the large dynamic frequency change,so as to achieve the accurate correction of frequency and phase.In order to improve the communication error performance of the system,the channel coding and decoding technology is combined with Multi-h CPM modulation and demodulation technology,which can realize effective detection of received signals under low SNR.However,it also means that the synchronization module needs to work properly with lower SNR,which will bring greater difficulties and challenges to signal synchronization.In this paper,on the basis of existing research,we conduct further theoretical research and optimization improve for synchronization module of coherent receiver at high-bit-rate,and design synchronization scheme with high performance which is able to adapt to the dynamic doppler frequency.Finally,our task of realizing the high-bit-rate Multi-h CPM telemetering receiver is accomplished,so as ralating tests.Our work may provide an important basis for further work in this field.