卫星通信地面终端射频一致性测试及仿真分析

介绍了卫星通信系统体制、地面终端的基带处理过程,以及发射机射频指标和测试算法,利用MATLAB和ADS软件搭建了基带信号生成模块、发射机模块,对终端发射机的发射功率、误差矢量幅度、占用带宽、邻道干扰进行了仿真。仿真结果表明,上变频器的射频带宽过小会使调制信号的误差矢量幅度增大,放大器工作在非线性区会对占用带宽和邻道干扰有较大影响,使发射机不满足射频一致性要求。本文的研究结果对设计卫星通信地面终端具有一定的借鉴意义。

Radio Conformance Test and Simulation of Ground Terminals in Satellite Communications

The baseband processing and radio transmission specifications of satellite communica- tions, system and its ground terminals along with their test algorithms are introduced. The MATLAB and ADS（Advanced Design System） are adopted to build baseband signal generating module and transmitter module. The transmitting power, error vector magnitude （EVM）, occu- pied bandwidth （OBW） and adjacent channel interference of transmitter are simulated. Simulation results show that if the RF bandwidth of up-converter is too narrow, EVM value of the modula- ted signal will increase substantially. They also reveal that when the amplifier is working at nonlinear region, the OBW and adjacent channel interference will be too high to satisfy the RF conformance requirements. The conclusion is helpful for the design of ground terminals in satellite communications.