扩频测控体制信号捕获方法分析

扩频综合基带设备集成了遥控、遥测、测距、测速等多种通用功能,在扩频测控体制的发展中占据重要的地位.针对综合基带设备的复杂需求,分析了传统信号捕获方法的局限性,在此基础上提出一种改进的扩频测控信号捕获方法.对载波多普勒范围进行子区间划分,采用二次频率调谐和分段积分累加来扩展频率捕获范围.引入非线性变换解决非相干测控体制下基带数据翻转造成的捕获性能恶化问题.通过仿真结果验证方法的有效性.最后分析了改进方法的捕获性能,可以为综合基带设备研制和测控体制参数设计提供参考.

Analysis on acquisition method in spread spectrum TT&C system

In spread spectrum telemetry, tracking and command (TT&C) systems, the integrated baseband equipment has been occupying an important role due to its high flexibility. Limitations of traditional methods were analyzed concerning the complex demands of the integrated baseband equipment. On this basis, a new acquisition method was put forward. The dynamic range of received carrier was divided into sub-intervals, and then dual down-conversions and sectional accumulations were adopted to accommodate larger doppler frequency. The deterioration of acquisition performance in non-coherent modulation systems was solved by a nonlinear transformation as well. Theoretical analyses and simulation results on the proposed method were given, which can provide reference for the design of integrated baseband equipments and for parameter determination in TT&C tasks.