Research On GPU-based GNSS Satellite Navigation Signal Processing And Application

After decades of development,the global satellite navigation system has penetrated into the fields of life,economic development and military affairs,and has bred a huge related industry chain;secondly,with the mutual competition and gradual modernization of various satellite navigation systems,research on non-cooperative satellite navigation system and adjacent radio astronomy environment is urgently needed.All these factors make the research on the processing of satellite navigation signals of great significance.However,there are few researches on the processing of satellite navigation signals at high sampling rates,and there is a problem of insufficient speed.The main work of this paper is as follows:Researched on parallel code phase search algorithm and serial frequency search algorithm,designed a GPU-based hybrid capture algorithm of parallel code phase and serial frequency,and performed B1 I signal and L1 CA signal search on satellite navigation signal data with a sampling rate of 250 MHz.The actual acquisition resulted in accurate satellite acquisition results and good acquisition speed performance.Aiming at the change characteristics of the autocorrelation amplitude with frequency in the captured results,a frequency search algorithm based on binary search was designed.The results show that in most cases the binary frequency search can obtain the same accurate results as the serial frequency search,and at the same time effectively improved search speed.The signal tracking loop implemented by the traditional Costa phase-locked loop was studied,and a fast signal tracking algorithm based on GPU was designed.The satellite navigation signal data at a sampling rate of 250 MHz was actually tracked by the B1 I signal and the L1 CA signal.The results show that the design in this paper can quickly track multi-channel satellites and obtain good carrier frequency and code phase tracking results.Based on the different frequency results obtained by the parallel code phase search and the serial frequency search,the influence of the initial frequency on the lock state of the carrier loop is studied.The results show that the serial frequency search can help the carrier loop enter the phase lock state faster.The synchronization and ephemeris calculation were optimized by using the multi-threaded concurrency technology,and the positioning results were successfully obtained in the actual calculation and positioning.Combining the research of capture,tracking and navigation in this paper,designed and realized the navigation signal receiving verification mode software based on GPU parallel computing,with the functions of optical fiber network communication,acquisition equipment parameter configuration,signal capture,tracking,positioning,result graph and text display and storage.The software achieved a fast and accurate capture and tracking effect.