卫星测控接收机相干自动增益控制设计与仿真  

Design and simulation of coherent Automatic Gain Control for TT&C receivers

作　　者：刘曦[1] 冯文全[1] 李春升[1] 朱楠[1] 

机构地区：[1]北京航空航天大学电子信息工程学院,北京100191

出　　处：《信息与电子工程》2012年第6期654-658,共5页information and electronic engineering

摘　　要：卫星测控通信系统中,由于通信距离远,目标动态范围大,造成接收信号的功率产生很大变化。为了保证接收机能够正常工作,有必要对接收信号进行自动增益控制(AGC)。传统的非相干AGC电路通过检测信号和噪声的总功率来控制增益,在低信噪比条件下不能使有用信号得到足够的放大。基于此,本文提出了采用相干功率检测的AGC设计方法,通过理论推导和仿真实验分析了相干AGC在低信噪比条件下为后续解调处理带来的改善。最后提出采用相干AGC与非相干AGC相结合的测控接收机结构以及相应的控制策略。经实际测试,接收机有效动态范围达到60 dB以上,证明本文所提出的方法是可行有效的。In satellites Tracking Telemetry and Command（TTC） systems,the received signal tends to have a great amplitude variation because of the long communication distance.Therefore,it is necessary to use the Automatic Gain Control（AGC） circuit to ensure the receiver’s proper functioning.The traditional non-coherent AGC circuits control the gain via estimating the total power of signal and noise,and the signal could not be amplified sufficiently when the Signal to Noise Ratio（SNR） is low.Consequently,a new AGC design scheme with coherent estimator is proposed.Theoretical analysis and simulation have proved the advantages of the coherent AGC under low SNR condition.The overall block diagram of the receiver based on coherent AGC and the relevant control strategy are presented.Experimental results of the actual receiver with the dynamic range above 60 dB,have also validated the proposed AGC circuit.

关 键 词：卫星测控接收机 自动增益控制 相干检测 信噪比 

分 类 号：TN927.2[电子电信—通信与信息系统] TN851[电子电信—信息与通信工程]