Design And Application Of BDS/GPS Dual Mode Positioning Receiver

With the rapid development of science and technology today,people's requirement of accurate location information is becoming more and more strong,the GPS system of the United States is the first global positioning system of the world,then has been widely used,and Russia,the EU and China have developed their own regional or global navigation satellite system.At present,Beidou navigation system of China has become the third mature satellite navigation system following the GPS of the United States and Russia's GLONASS.However,sometimes because the number of satellites,satellite geometric distribution and satellite signal or other factors,the positioning accuracy and reliability can not be fully guaranteed when a single satellite navigation system is in use,therefore,all the countries in the design of each satellite system is also considered compatible interoperability between systems,based on the above analysis,this thesis proposes design and application of BDS/GPS dual mode positioning receiver.The dual mode positioning receiver designed in this thesis mainly includes six parts:antenna module,radio frequency module,baseband unit,display and display control unit,power module and structure part.Among them,antenna module,radio frequency module,display control unit,power module and structural parts all put forward corresponding index for external procurement.This thesis mainly completes the design of hardware and software of the baseband unit and the commissioning test of the whole machine.First,the overall design of the dual mode positioning receiver's function is carried out,and the technical index requirements of antenna module,radio frequency module,display and control unit,power module and structural parts are put forward.Secondly,the paper introduces the hardware design of baseband unit in detail.Including components selection,interface design,schematic drawing,PCB platoon and plate making.Thirdly,the paper introduces the software design of the baseband unit in detail,including the software design of DSP and FPGA.DSP software design includes initialization,initialization of satellite acquisition and tracking channel,acquisition and tracking of satellite signals,extraction of navigation message,location and time calculation,etc.The design of FPGA software includes the construction of satellite capture tracking channel,signal demodulation,despreading and pseudo range calculation.Finally,the paper analyzes and collate the indicators of the whole machine after debugging the hardware and software,and sorts out the shortcomings of the design,and puts forward the follow-up improvement plan.