Design And Implementation Of Wireless Transceiver In Local Positioning System Based On FPGA

The main purpose of this thesis is to design a synchronous time signal all-digitaltransceiver for the local timing and positioning system. It is based on direct sequencespread spectrum communication principles. The transmission system mainly consists of thebaseband processing unit and the band processing unit. The receiving system mainlyconsists of the demodulation unit and the despreading unit. All modules in the entireproject are designed with Verilog HDL, simulated and verified using ModelSim andSignalTap. At last, all the modules are connected together and the entire project isimplemented in an Altera’s Cyclone IV Series FPGA (Field Programmable Gate Array)chip.First, this thesis presents a kind of local timing and positioning system which isadapted to field work. Then it introduces the overall structure of the transceiver from theengineering point of view and designs the transceiver system parameters and the filtercoefficients used in the system. This thesis also discussed the theoretical basis of thevarious modules in transceiver systems as well as detailed methods of their implementation.The transmitter includes differential encoder, spreading sequence generator and NCO(numerically controlled oscillator). The receiver includes Costas loop, ahead-hysteresisloop, matched filter and a differential decoder. The modules simulation waveforms aregiven in thesis. Finally, download the project to the Altera DE2-115development boardwhich is equipped with the latest FPGA technology to verify the design.Verification results show that the whole system works correctly, is stable, occupiesfew resources and fully satisfies the requirements.