Research And Implementation Of Gps Software Receiver

As the development and innovation of the technology of GNSS it has been used in many fields。GNSS has caused great changes in our daily life. At the same time it largely impact the security of China and cause new requirement of national defense construction. As being the leader in satellite navigation system, the study in GPS will help to advance the cause of the rapid development of China's satellite navigation. and enhance the core competitiveness in this field. This article research on the tracking base band algorithm design with completely independent intellectual property rights of software GPS receiver based on the RF front-end capture with homemade chips.At first, elaborate on the principle of GPS spread spectrum communication system basic navigation and positioning from the view of signals.Secondly, after studying the basic GPS signal acquisition theory, analysis today's complex communications environment and then put forward a new capture method based on adaptive hangs in the capture threshold. Through the analysis and compartment of existing adaptive research, find a few defect deficiencies and then design the capture method basic on adaptive changes after theoretical analysis and lot of Matlab experimental data to demonstrate the feasibility of the design and performance superiority.Again, in the tracking phase of signal. the article firstly describe the principle of the carrier tracking and pseudo-code tracking in detail. Then using Matlab mathematical model to expand the description, discussion and analysis based on the performance of PLL and FLL.On this basis, take into account the dynamic performance and accuracy requirements of the PLL and FLL fulfill the carrier tracking loop. In pseudo-code tracking loop, design for normalize dot product power algorithm. Guarantee the good performance of discriminator with more rapid performance of the discriminator considering the cost of hardware.At last, propose the Receiver RF front-end design. Starting from the design goals, design every key module with the help of ADS tool to determine the matching circuit chip peripheral structures. Achieve the performance objectives of the design.