Research On Collision Continuous Signal Separation In Satellite Communication System

With the rapid development of satellite technology,satellite communication has been more and more used in various fields of modern life.Satellite communication system is a resource-limited system,in which uplink access is limited in main frequencies and downlink broadcasting is limited in power.With the advent of ground 5G era and the emergence of new access scenarios such as the Internet of Things,the scarce spectrum resources become more strained.How to improve the utilization of spectrum resources of satellite communication system will be a key problem affecting the development of satellite communication system in the future.Current techniques indicate that spectrum utilization can be improved by spectrum sharing between receiver and receiver,such as Paired Carrier Multiple Access system,but signal separation technology at the receiver is the key to achieve this.In view of the signal separation technology requirements of the receiver in the above system application,this paper studies the adaptive cancellation technology for continuous communication signals,in order to promote the engineering application of this technology.The main contents are as follows:1.There are many steps in the estimation process and insufficient accuracy in the initial estimation of interference signals in the traditional signal separation algorithm.In this paper,a corresponding improvement method is proposed.Firstly,the pilot sequence captured in the mixed signal is preprocessed according to the stationary time of the channel,and the frequency difference and difference information are extracted by using the characteristics of known sequences of local reference signals.Then,Amplitude and Phase Estimation algorithm is used to complete the joint Estimation of frequency difference and Phase difference at one time and guide the loop for fast tracking.2.For the inevitable frequency,phase deviation and drift problems in continuous communication signals,a complete adaptive tracking and canceling process is designed.The process consists of two parts: parameter adaptive tracking and waveform adaptive fitting.First,the Costas loop is used to track the frequency difference and difference between the local signal and the interference signal.Then,the Least Mean Square adaptive filter is used to complete the waveform fitting at the sub-sampling point level and the signal separation of mixed signals is completed.The simulation results show that the performance of the proposed signal separation method is about0.5d B better than the existing methods under the same simulation conditions.3.The simulation software platform of signal separation is built,including data generation module,processing module and display module.The separation effect and performance of the method proposed in this paper are verified through the simulation platform.4.The SMBV100 B vector signal generator is used to generate two actual signals.The hardware-in-the-loop simulation is carried out to verify the signal separation method proposed in this paper.The experimental results show that the adaptive cancellation algorithm proposed in this paper can be used for signal separation of real signals,which lays a foundation for subsequent hardware implementation.