导航卫星星间链路信号质量参数评估算法

传统的微波调制信号质量评估需要将微波信号变频到中频后进行处理,变频处理会引起非线性失真问题,而且星间链路信号许多关键质量参数如相位一致性、相关损失、I/Q(Inphase/Quadrature,同相/正交)支路功率比等无法用传统评估方法完成,针对这些问题,提出了采用软件无线电技术的导航卫星星间链路信号质量评估算法,利用高速采样器对导航卫星的星间链路信号进行直接射频采样,在数字域对星间链路信号进行相关接收和解调,实现所有关键质量参数的评估.该方法避免了使用变频器带来的附加失真,采用该方法完成实际星载设备的信号质量评估的结果表明,该评估算法精度高,能满足导航卫星星间链路设备信号质量参数评估要求.

Assessment Algorithm for Crosslink Signal Quality Parameters of Navigation Satellites

In traditional quality assessment of microwave modulated signals are down converted to intermediate frequency for processing and this introduces nonlinear distortion.Some quality parameters of crosslink signals cannot be assessed with the traditional method such as phase consistence, correlation loss, and power ratio of I/Q (Inphase/Quadrature) branches.To solve these problems, a method using digital processing algorithm is proposed.The crosslink signal is directly sampled by high speed samplers.Coherent receiving and demodulating are done based on soft defined technology. Then, all quality parameters can be assessed.Distortion induced by down converters is avoided.Signal quality evaluation has been made on actual onboard equipment using the proposed method. Analysis results of the assessment show that the accuracy of assessment with the proposed algorithm is very high and meet requirements for crosslink signal quality assessment for navigation satellites