Tracking Algorithm Design And Performance Analysis Of AltBOC Signal Set

With the development and modernization of the GNSS, navigation service continues to expand and more and more signals are broadcasted by different satellite navigation systems in the same frequency band. The navigation signal design is faced with the difficulty of the spectrum resource have become crowded, the signal must be constant envelope and user requirement is more and more high. However AltBOC signal set derived from AltBOC solves these problems. TD-AltBOC, ACE-BOC and AltBOC, as typical members of AltBOC signal set, the performance of them is bone of contention. Besides it is flexible but difficult to track these signals. So it is necessary to do research on the tracing algorithm of these signals and make a comprehensive performance comparison of TD-AltBOC, ACE-BOC and AltBOC. The results of this paper can provide reference for the GNSS signal design and tracking.This paper firstly analyzes the basic principle of TD-AltBOC, ACE-BOC and AltBOC. Secondly, mathematical model of coherent dual band tracking is established. And dual estimate, bump jump technique and PCF method are applied to the AltBOC tracking and the corresponding mathematical model is derived. Then the simulation signal is used to be tracked by the three dual band tracking algorithms, tracking results show that tracking performance of dual estimate is the best. Thirdly, the necessity of data/pilot combining tracking is analyzed, and mathematical model of non-coherent and coherent combining tracking are given. And the best weighted coefficient of coherent combining tracking is given and proved. And new coherent combining tracking method based on probability weighted is proposed. Then the results of tracking the simulated signal by different data/pilot combining tracking methods show that the new method proposed in this paper can not only enhance the carrier tracking accuracy, but also can reduce the carrier tracking threshold. Finally, a comprehensive performance comparison of TD-AltBOC, ACE-BOC and AltBOC is made, including multiplexing efficiency, out-of-band power loss, tracking accuracy, power consumption and hardware resource consumption. The results show that the TD-AltBOC signal has certain advantages in all aspects.