Using Fuzzy Logic Controller with Adaptive Detection Scheme for Fast Acquisition of GNSS Signals

in International Symposium (oral presentation paper), 國際研討會(全文口頭發表)
標題Using Fuzzy Logic Controller with Adaptive Detection Scheme for Fast Acquisition of GNSS Signals
出版類型國際研討會(全文口頭發表)
出版年度2009
AuthorsChung-Liang Chang, 張仲良
出版日期Nov 28 2009 12:0
會議地點國立台北科技大學
其他編號0000
中文摘要

The paper presents a fuzzy logic controller (FLC) with adaptive threshold control scheme to regulate the frequency search step size so as to enhance the performance in GNSS signal acquisition. The FLC is employed to regulate the frequency search step size in frequency domain on the basis of input variable: code correlation value and its rate of change. These input variables are fuzzified and determined by a set of linguistic labels characterized by the membership functions predetermined for each class. The fuzzy controller’s output is obtained through the adoption of 25 rules to associate the fuzzified input variables with the fuzzy controller’s output, fuzzy set theory, and related fuzzy logic operations. The fuzzy set depicting the controller's output in terms of linguistic labels is defuzzified to acquire the step size output value which is employed to regulate the frequency search step size and obtain rapid signal acquisition. To enhance the signal acquisition performance under various environments, the signal detection threshold is adaptively adjusted and combined with FLC. Hence, the input and output parameters of membership functions (MFs) vary with the adjustment of detection threshold. Simulations and experiment results demonstrate that the proposed FLC with adaptive threshold control scheme enhances acquisition performance with regards to execution time and precision of parameters in GPS and Galileo In-Orbit Validation Element (GIOVE-A) signals. The proposed method is capable of combination with any code correlation algorithm to ensure fast signal acquisition in the presence of noise and co-channel interference.

網址http://cacs2009.ntut.edu.tw
校址:912 屏東縣內埔鄉學府路1號 總機:886-8-7703202 傳真:886-8-7740165 系統開發統維護單位:國立屏東科技大學 電算中心 版權所有