Study on MSK modulation and tracking technique for satellite navigation systems

The applications and tracking technique of the signals based on the minimum shift keying (MSK) modulation for Global Satellite Navigation Systems (GNSS) are presented. The general mathematical model of the MSK modulated signals is established and the biased tracking for the minimum shift keying - binary offset carrier (MSK-BOC) modulated signals is demonstrated. Then, the modified BOCPRN algorithm based on the sine shaped local chip pulse is proposed to remove the threat of potentially giving biased measurements of MSK-BOC (n, n) signals. The performance in terms of tracking accuracy is theoretically analysed and the architecture of the code tracking loop in accordance with this algorithm is demonstrated. The results indicate that this unambiguous tracking algorithm has an acceptable tracking performance and can make the complexity of the required hardware and software blocks be reduced.