GNSS Receiver Signal Tracking

This chapter provides an integrated overview of the fundamentals of global navigation satellite system (GNSS) signal tracking and the latest developments in advanced signal tracking techniques to improve sensitivity, robustness, and accuracy of performance. It begins with the objectives of signal tracking, followed by a conceptual description of a closed‐loop tracking system. A brief conventional treatment of code delay lock loop (DLL) is then presented. Carrier tracking is the more challenging and more intensely researched subject. The chapter summarizes the conventional phase lock loop (PLL) design. Tracking of simulated GPS L1 signals will be used to illustrate the concepts presented in the traditional implementations of DLL and PLL techniques. Following the conventional PLL description, the chapter presents a state space‐based feedback control theory to demonstrate that some of the popular carrier tracking loop implementations are fundamentally equivalent. Finally, it summarizes the latest developments in inter‐frequency aiding.