船载遥测接收信道门限特性的研究

对船载遥测接收信道一项最重要的传输特性———门限特性进行理论分析,并指出门限特性对执行测控任务和设备性能检测的特殊意义。首先阐述门限效应产生的本质即增加传输带宽是在恶化输入信噪比的前提下提高输出信噪比,输入信噪比的域值即为门限。结合各种不同的船载遥测信道门限输入信噪比,提出统一的、具有普遍意义的标定方法:即调制度定标和载波信噪比的标定。根据信道本底噪声的不同,又分为射频有线和无线两种测试方式,给出了详细的测试过程和步骤。最后还分析双模环电路由于实现了载波的动态跟踪而能显著降低门限效应。

Study of the Recieving Threshold of Telemetry Receiving Channels on Board Ship

The threshold characteristics of the telemetry receiving channels on-board ship are researched,and the importance of the threshold characteristics of the telemetry receiving channels to the performance of TT&C task and the test of equipments is described in this paper.At first,the nature of threshold characteristics is unveiled.The calibrations of the input SNR on threshold of universal significance are proposed,which are the modulation degree calibration and the carrier SNR calibration.The test procedure are presented.At end,it is pointed out that the threshold can be significantly reduced by the use of the dual-model loop circuit because of the realigation of the dynamic tracking of carrier.