基于卡尔曼滤波的锁相环算法研究

Research on the Locking Loop Algorithm Based on Kalman Filter

在某卫星载荷感应式磁力仪的设计中,需要提取高动态环境下的磁场信号并降低所获信号的噪声干扰。基于此提出了一种改进的基于卡尔曼滤波的锁相环算法并应用于感应式磁力仪数据处理单元DSP的软件设计中,设计采用扩展卡尔曼滤波结合全数字软件锁相环的方法对信号进行滤噪、跟踪,并进行了仿真和实验验证。结果表明,改进的锁相环可以有效的对多普勒频率变化率f=500 Hz/s,信噪比低至-20 d B的信号进行跟踪。该方法已应用于感应式磁力仪的信号提取。

In the design of a satellite load magnetometer,it is necessary to extract the magnetic signal in high dynamic environment and reduce the noise interference.In order to improve the reliability of signal and avoid the situation of false lock and jitter under high noise and high dynamic environment,a new method that combines traditional software Phase-locked Loop and Extended Kalman Filter is proposed.The proposed method provides an effective approach to improve the accuracy of the small-signal.Experimental results show that the proposed method can track the signal effectively when the rate of Doppler frequency is 500 Hz/s and SNR is-20 dB.