The present invention proposes a method capable of effectively tracking
Doppler frequency change rate signals with extremely low
signal-to-
noise ratio, aiming to provide a method that can more accurately and effectively track extremely low SNR
Doppler frequency change rate signals in deep space measurement and control. Technical methods for measuring and controlling signals. The present invention is realized through the following technical solutions: the measurement and control
receiver obtains the received
signal through A / D sampling, and locks and tracks through the ultra-
narrowband third-order phase-locked loop in the
mathematical model of the phase-locked loop, and extracts the
signal Doppler from the loop. Le, the received signal enters the
intermediate frequency ultra-
narrowband digital phase-locked loop, and the
Doppler frequency and Doppler change rate are sent to the third-order phase-locked loop, and then the ultra-
narrowband phase-locked loop and the digital third-order phase-locked loop are used to
Narrowband carrier loop to track deep space measurement and control signals with extremely low signal-to-
noise ratio and Doppler frequency change rate. The invention combines extremely narrow carrier
loop bandwidth and digital third-order phase-locked loop to effectively solve the problem of tracking the measurement and
control signal by the download wave loop under the condition of multiplier frequency change rate when the signal-to-
noise ratio of the received signal is very low.