Design of Intelligent GPS Receivers in Kinematic Environments

Carrier phase measurement is essential for high accuracy kinematic positioning in mobile global position system (GPS) applications. For GPS receiver design, a narrow noise bandwidth is desired to decrease phase jitter due to thermal noise. On the other hand, it will deteriorate the capability of tracking loop and result in a cycle slipping. Based on narrow bandwidth criterion, a novel intelligent GPS receiver is proposed for solving the carrier phase tracking problem in the presence of high dynamic environments. In order to maintain lock on diversity of phase signals, a rule-based intelligent phase error estimator (IPEE) is developed in carrier loop to switch between two modes, i.e. fuzzy inference system control (FISC) and normal operation (NOPR) modes. Two kinds of FISC approaches, namely fuzzy logic control (FLC) and adaptive neuro-fuzzy control (ANFC) methods with simplicity and easy realization properties, are designed to perform rapid and accurate control of digital frequency phase locked 毛偉龍 應用於動態環境之智慧型全球定位系統接收機設計 2 明志學報第 37期 loop (FPLL). A new design procedure for kinematic GPS receiver development is also presented. The computer results show that the FISC-based receiver achieves faster settling time and wider pull-in range than the conventional tracking loops while preventing the occurrence of cycle slips.