A Study on the Tracking Loop Design for Weak Signal in High Dynamic Environment
Kihoon Lee, Taegyoo Lee, Ki‐Won Song · 2007
In this paper, we design a signal tracking loop which is appropriate for weak power signals in high dynamic application. Satellite signal’s power is reduced in situation of low elevation angle or jamming signal. To track the weaken satellite signal stably, the bandwidth of signal tracking loop should be small if it is possible. But the tracking loop is broken if we make the bandwidth too small in high dynamic conditions because the input errors are increased by vehicle dynamics including reference oscillator’s frequency error. We design an adaptive tracking loop which has a variable bandwidth according to the conditions such as SNR, elevation angle and vehicle’s accelerations. Also, The adaptive tracking loop has a capability to track the satellite signal with C/No 28dB-Hz, which is relatively low if compared with other commercial GPS receivers with C/No 33dB-Hz, because the designed PIT(Predetection Integration Time) is 10ms. We experiment and analyze the signal tracking performance of the designed tracking loop in circumstance of weak signal power under high dynamic environment with GNSS receiver using simulator that generates high dynamic environments.