高动态条件下测控系统载波跟踪环路优化设计

航天测控系统中载波跟踪误差主要来源于热噪声和航天器动态应力,对载波跟踪环路的优化一般通过调整环路等效噪声带宽来实现.分析了航天测控系统中航天器的动态应力特性及环路跟踪误差特性,导出由载噪比和动态应力决定的环路最佳带宽表达式,提出一种通过环路自身状态估计载噪比和动态应力的方法,通过对载噪比和动态应力的实时估计实现对环路参数的实时调整.仿真结果表明,该算法在动态应力和载噪比时变的高动态场合可以实现稳定的载波跟踪,测量精度得到明显改善.

Optimization of TT&C Carrier Tracking Loop in Dynamic Environments

The carrier tracking error in TT&C(Telemetry,Tracking and Command) system is mos tly comprised of the thermal noise error and dynamic stress error.Loop bandwidth adjustment is the general way to optimum the performance of the carrier trackin g loop. Based on the analysis of spacecraft dynamic characteristic and the error chara cteristic of carrier loop, an optimal loop bandwidth which can yield the minimum error in specified carrier-to-noise ratio and dynamic stress is presented. Addi tionally, an estimation method which can extract the carrier-to-noise ratio and d ynamic stress real time from the carrier tracking loop itself is developed. By d etecting the carrier-to-noise ratio and dynamic stress, the loop parameter is ad justed adaptively to minimize the tracking error. The simulation result shows th at the algorithm is efficient to improve the precision of carrier tracking i n high dynamic circumstance.