The Research And Realization Of BeiDou Ⅱ Receiver

BeiDou is a global navigation satellite system, and it’s developed and run by our country independently. It’s development is extremely important to the military, agriculture, fishery, transportation, and mapping and many other field. Firstly, the dissertation briefly introduced the BeiDou satellite navigation system. Secondly, briefly introduced the theory of positioning, velocity measurement and time service. After that, showed the design of the whole system of receiver. Thirdly, designed a hardware platform, which is based on DSP and FPGA, and contained the front-end, FPGA unit, and DSP unit and other auxiliary device. Using the XC6SLX150and TMS320C6414T as the center processor; Fourthly, keynoted the design and realization of base-band processing. It analyzed and compared three different acquire engines, who are the sliding correlation algorithms, FFT-IFFT, and PMF with FFT of short length. On this basis, choose the FFT-IFFT as the acquire engine of the receiver. At the same time, improved the FFT-IFFT algorithms for the NH coding. It also researched the tracking loop, which contained carrier tracking loop and code tracking loop. And choosing the third-order PLL assisted by second-order FLL as the carrier tracking loop, and using the DLL as the code tracking loop. After that, it also discussed the bit synchronization and frame synchronization, and using the histogram method to realized the bit synchronization. Fifth, it introduced the theory and process of PVT and the WLS in detail. At the same time, using the carrier phase to smooth the pseudo-range to improve the positioning and using the α-β-γ filter to improve the velocity measurement in design. The test show that this two ways are feasible. In the end, test the receiver with static and high-dynamic scene, and the consequence showed that it meet the design goal.