摘要
USB卫星测控体制是现行航天测控领域的通用体制之一,对卫星的状态监测、姿态控制和轨道修正等需要通过调制载波实现遥测、遥控、测量信息的传递和交互,当副载波信号处于大调制度的情况下,容易造成载波错锁或假锁。本文在工程实践的基础上,总结了载波错锁产生的原因,基于Matlab/Simulink建立了高斯白噪声影响下的中频接收载波环模型,仿真分析了不同调制度下的载波时频特性,提出奇异值分解(Singular Value Decomposition,SVD)降噪实现特征信号提取。通过仿真验证,副载波解调与频谱分析能有效抑制调制度较大的副载波分量,实现载波信号捕获,克服了大调制度下的载波错锁问题。
USB satellite TT&C system is one of the commonly used systems in the field of aerospace TT&C.For satellite status monitoring,attitude control,orbit correction and so on,telemetry,telecontrol,transmission and interaction of measurement information need to be realized through modulated carrier.When the subcarrier signal is under a high modulation degree,false carrier lock is easily caused.On the basis of engineering practices,reasons for false carrier lock are summaried in this paper.The medium frequency receiver carrier loop model under the influence of Gauss white noise is set up by Matlab/Simulink.The carrier frequency characteristics of different modulation systems are simulated and analyzed.Then,SVD noise reduction method is put forward to realize the extraction of characteristic signal.Carrier signal acquisition is achieved by subcarrier demodulation and spectrum analysis.Finally,the method is validated by simulation to overcome the problem of false carrier lock under high modulation degree.
作者
李俊瑶
高海南
冯程
臧进
LI Junyao;GAO Hainan;FENG Cheng;ZANG Jin(State Key Laboratory of Astronautic Dynamics,Xi’an 710043,China;Xi’an Satellite Control Center,Xi’an 710043,China)
出处
《无线电工程》
2018年第12期1091-1095,共5页
Radio Engineering
