Research On Dual-satellite Joint Communication Channel Model For Nearspace Hypersonic Vehicles

Plasma sheath will be formed surrounding a near-space vehicle when it flies at hypersonic speed.Communication signal will be degraded severely and it may result in acquisition,tracking,telemetry and navigate failure to the worst case.From the communication perspective,the main cause of the communication blackout is that the selected communication system doesn't match the dynamic plasma channel.Thus it is very important for communication studies to establish accurate channel model.Unfortunately,almost all studies have remained in the research about the “end to end” channel model as so far.The role of multi-platform joint communication to improve the communication quality are not considered.Based on the idea of angle diversity,this paper conducts a research about dual-satellite joint communication channel model.The premise of the study is to establish accurate the dynamic plasma sheath channel model and the nearspace-space channel model.In this paper,a Hidden Markov chain is proposed to model the dynamic plasma sheath channel.The reversible jump Markov Monte Carlo algorithm is utilized to estimate the state numbers and their parameters.On the light of the land mobile satellite channel model,the nearspace-space channel model is completed by adding the plasma sheath amplitude attenuation channel to atmospheric channel model.Finally,this paper takes dual-satellite joint communication into consideration.Based on the state transition matrix of single satellite and the correlation coefficient,the dual-satellite four state Markov model is established.The communication quality improvement is analyzed for various combinations of elevation and azimuth separations.The reversible jump Markov Monte Carlo algorithm introduced to model dynamic plasma sheath in this paper can estimate the state numbers under different environments adaptively.The established Markov model has unified profile expression and definite physical meanings.Furthermore,it can satisfy the first-order statistical properties well and it can avoid introducing error compared with manual state number setting.The simulation result under the dual-satellite joint communication channel established in this paper,compared with single satellite communication,indicate that the communication quality will improve obviously,and communication quality might be reach an optimal level under reasonable selection of elevation and azimuth angle combination.