GPS RF Front End Design And Research Of GPS Signal Acquisition Method

GPS RF front end end and GPS signal acquisition method are very important in GPS receiver.The performance of the former directly affect on GPS receiver sensitivity and signal processing.The performance of the later determine the receiver capability of useful signal capture. So this paper is mainly purpose to study GPS RF Front and GPS signal acquisition method.Firstly, based on studying the basic knowledge of GPS and RF circuit design, this paper discusses the method of GPS RF front design and how to apply Zarlink GP2010 to design it.Secondly, this paper study FFT acquisition method respectively based on carrier wave and code phase.The results show that FFT acquisition method based on code phase can search all code phase cells at searching one doppler cell and FFT acquisition method based on carrier wave can search all doppler cells at searching one code phase cell, having large frequency range and hardware is realized easily.Then the GPS signal acquisition technique under low SNR environment is studied. By reaserching and simulating coherent integration and non-coherent integration, this paper shows that respective disadvantage of them.Finally, differentially coherent integration method is introduced emphatically. The simulation results prove that this method is very suitable for GPS signal acquisition under low SNR environment because it can eliminate the shortcoming of above methods and its performance is far better than them.At the same time, this paper put forward three method of noise power estimaton by acquisition thresholds study, especially noise power estimation study in adaptive threshold. And eventually put In order to increase the detection probability of acquisition, and evaluate the performance of the Tong detector and M of N detector, this paper deduces theoretical formulas for the overall probability of false alarms, the overall probability of detection, and the mean number of dwell times. The function of detector parameters and acquisition performance are demonstrated by numerical simulations.The results contribute to how to confirm detector parameters.