Multi-task Scheduling Method for GPS Receiver Software and its Performance Analysis and Test
Yong Luo · Gnss World of China · 2011
In the paper,the GPS L1 baseband correlation was implemented on the platform of Altera FPGA,and software schedule of the function modules was implemented based on eCos multi-task operating system.Two kinds of test method of task execution time were proposed and validated by each other's result.Software scheduling model based on single-task system and multi-task system were analyzed separately and compared.Base on that,the two models' effect on CPU efficiency and output rate was studied.The test results of real data show that if the receiver software established based on multi-task system,the efficiency is improved 1.2 times than single-task system,when 5 satellites are visible,pseudo-range output frequency is 10 Hz and navigation solution output frequency is 5 Hz.The work suggests that receiver software on the platform of multi-task system can improve CPU efficiency,moreover,data output rate can be increased or software algorithm can be more complicated when necessary.