高动态卫星导航信号多普勒频率模拟方法

Doppler simulation method for high dynamic satellite navigation signal

针对卫星导航信号模拟源在高动态场景下对多普勒频率模拟难度较大的现状,提出了一种基于相位重置的三阶DDS导航信号模拟算法。该方法从卫星与接收机之间的相对运动物理模型着手,建立了一种基于数字电路的三阶DDS模型,可有效地模拟出高动态场景下导航信号中含高阶项的多普勒频率。此外,通过对三阶DDS模型中关键参数进行相位重置以避免累计误差。在计算机中进行仿真,其结果表明在速度为10000 m/s,加速度为1000m/s^(2),急动度为1000 m/s^(3)的高动态场景下,该算法相较于传统算法多普勒频率模拟精度提升了31 dB,且不会因急动度增加导致精度恶化,多普勒频率模拟精度可达-36 dB或更高。说明该方法在高动态场景下可精确地模拟导航信号的多普勒频率,且具有一定的鲁棒性。

A third-order DDS navigation signal simulation algorithm based on phase reset is proposed to address the difficulty of simulating Doppler frequency in high dynamic scenarios for satellite navigation signal simulation sources.This method starts with the physical model of relative motion between satellites and receivers,and establishes a third-order DDS model based on digital circuits,which can effectively simulate the Doppler frequency of navigation signals containing high-order terms in high dynamic scenarios.In addition,phase reset is performed on key parameters in the third-order DDS model to avoid cumulative errors.Simulation was conduct⁃ed in a computer,and the results showed that in a high dynamic scenario with a speed of 10000 m/s,an acceleration of 1000 m/s^(2),and a jerk of 1000 m/s^(3),the algorithm improved the Doppler frequency simulation accuracy by 31 dB compared to traditional algorithms,and did not deteriorate accuracy due to increased jerk.The Doppler frequency simulation accuracy can reach-36 dB or higher.This method can accurately simulate the Doppler frequency of navigation signals in high dynamic scenarios and has a certain degree of robustness.