Design Of GPS Receiver Based On DSP Technology

GPS receiver has been the investigative focus, owing to its' extensive applicationand the wide prospects in the field of spaceflight, aviation, sea engineering, soilsurvey, land navigation and military navigation. The key algorithm and system'srealization involved in GPS receiver system is researched in the paper. The main workis presented as below:(1) The study focuses on glide acquisition algorithm, code delay-locked loop,carrier four-quadrant frequency discriminator and frequency-locked loop. Animproved acquisition algorithm is dealt with. The new algorithm can accelerate thespeed of acquisition processing. A revisited algorithm for code tracking loop arepresented. The algorithms are relatively simple in terms of computational effort andhardware reduction.(2) Based on the core processor of DSP and the other chips, the author hasimplemented the GPS receiver system's design including its software and hardware.About the aspect of hardware, the system's main frame is built according to the GPSreceiver system's function. The key modules' design is expounded, and the circuit ofDSP hardware part is designed mainly.(3) For further study, the method of software development for DSP system isdiscussed, and the hardware driver is programmed. Moreover, DSP boot methodonline is designed. Finally, based on DSP/BIOS, multitask design and the interruptservice routine (ISR) are implemented. In the part of ISR, the author has investigatedthe structure of software and program flow chart of code tracking loop, carriertracking loop, data bit synchronization and data frame synchronization.