星地链路建模与分析

卫星网络技术以其独特优势成为研究热点,本文以卫星地面链路作为研究对象,对星地链路进行深入分析,细致刻画链路特性,在此基础上归纳星地链路延时的构成因素,从固定延时、可变延时和突发延时3个方面考虑,建立了时变的星地链路延时模型.详细分析了链路中影响误码率的各种损耗和噪声源,建立了基于卫星链路功率预算的链路误码率模型,基于给定的星地链路场景对延时和误码率模型进行了对比验证.结果表明本文提出的延时模型能够更细腻地刻画星地链路的延时,更精细地反映链路延时的变化特性;误码率模型考虑的因素更加全面,能够更真实地刻画星地链路的误码特性.两个模型可以作为卫星链路分析和设计的一个有效辅工具.

Modeling and Analysis of Satellite-ground Link

By it’s special superiority,satellite network technology has become a hot research field;this paper takes satellite-ground link as research object;analyzes the satellite-ground link in depth,characterizes the feather of the link in detail.Then presents the delay components analysis of satellite-ground link from fixed delay,variable delay and burst delay,builds a time-varied satellite-ground link delay model.Based on the detailed analysis of the many factors that cause attenuation and noise to the radio wave signals,this article gives a bit error model of satellite-ground link on link power budget analysis.In the following,the two models are verified with the data generated by STK software,the results represent good accommodation.In the delay model,there is a fine-grained characterization and thus is able to reflect the delay diversification of the link better.With comprehensive factors taken into account when realizing the bit error rate model,the final model presents a true reflection of the real case.The two models play as an active supplementation in satellite-ground link design and analysis.