Research And Application Of Plesiochronous Technology In Tropospheric Scatter Communication Network

In tropospheric scatter communication,because of the increasing requirements on transmission rate and transmission efficiency,it is necessary to combine several low-speed digital signals into one high-speed digital signal by digital multiplex technology to expand transmission capacity and improve transmission efficiency.The digital multiplex technology is divided into synchronous multiplex,plesiochronous multiplex and asynchronous multiplex.Among them,plesiochronous multiplex has the characteristics of high efficiency and short transmission delay.The plesiochronous technology in the title is the justification technique and timing recovery in plesiochronous multiplex,and the principle of justification is simple and easy to implement,so this paper focuses on timing recovery method in plesiochronous technology.The tropospheric scattering communication has the characteristics of anti-interference,anti-interception and anti-destruction,so it still occupies a place in the field of communication even though satellite communication and optical fiber communication are becoming more and more popular.However,in the development of multi-hop scatter communication network,the clock drift will be caused by accumulation of timing errors when the number of hops is large.The serious clock drift will make the final recovered clock not up to the standard and cause error code.Therefore,this paper proposes a dual-loop timing recovery method which can solve the problem of the accumulation of clock jitter in multi-hop scattering communication effectively.On the basis of reading a lot of related literatures,this paper analyzes the traditional plesiochronous technology and improves the traditional timing recovery method.The main work of this research is as follows:Firstly,studying the existing timing recovery method and proposing an improved method.Then,Using simulation tools to simulate the method in various situations.Finally,the dual-loop timing recovery method proposed in this paper is applied to the system.Through the actual test of the plesiochronous multiplex equipment,obtain the waveform of two clock recovery methods.