Design Of General Development And Verification Platform For Pseudolite Satellite Based On Software Radio

Pseudo-satellite is a ground wireless navigation device that can emit GPS / BDS-like signals.It can effectively make up for the deficiencies of the GNSS system in indoor and other complex sheltered environments.The signal is weak and the positioning accuracy is poor.Build pseudo-satellite independent networking to achieve indoor and outdoor navigation and positioning in special environments.The general pseudo-satellite equipment only realizes the transmission and reception of navigation signals.Its interfaces are few and the scalability is poor.It is limited to pure application links,which greatly limits the development of research and design of pseudo-satellite related technologies and algorithms,and is not very good.Assist in further research of diverse GNSS systems.In order to solve this kind of problem,based on the design idea of software radio,this paper uses mature software and hardware technology to complete the design and implementation of the pseudo-satellite general development and verification platform,and complete the design verification of the pseudo-satellite transmitter and receiver.On the unified and common hardware and software platform,through the design of software programs to realize the transmission or reception function of pseudo-satellite signals of different signal systems,product design,engineering development,algorithm verification for various systems and types of pseudo-satellite equipment Provides a common hardware and software platform,which is conducive to the development of related research work.First,based on the conventional pseudo-satellite signal system and system structure,the basic functions and design principles of the pseudo-satellite general development and verification platform are analyzed to complete the design of the general technical scheme of the universal platform.It is determined that the digital baseband board uses DSP and FPGA as the core processor,the RF front-end uses the highly integrated LMS6002 D module,and completes the device selection and hardware circuit design such as communication and clock.Secondly,the GPS signal system is used to complete the software design and verification of the GPS pseudo-satellite transmitter on the platform.According to the GPS pseudo-satellite signal system and transmitter technical requirements,complete the design of pseudo-satellite launch software program.According to the technical requirements of the transmitter,the GPS baseband logic design and the parameter configuration software design and verification of the RF front-end transmit channel are completed on the FPGA,and the design of the local oscillator leakage is corrected.Introduce geometric accuracy factors,analyze and study the layout scheme of pseudo-satellite software transmitters,and provide a basis for transmitter layout networking.Then,the GPS signal system is used to complete the software design and verification of the GPS pseudo-satellite receiver on the platform.According to the GPS pseudo-satellite signal system and receiver technical requirements,complete the pseudo-satellite receiving software program and near-linear AGC signal processing program design.According to the requirements of the receiver design plan,complete the parameter configuration,DC suppression,AGC and other software design for the RF front-end receiving channel on the FPGA,and select the appropriate signal acquisition,tracking and observation data acquisition algorithm,and use collaboration on the DSP + FPGA Working mode,complete the software design and verification of signal acquisition,tracking,synchronization and despreading and data acquisition.Finally,a comprehensive hardware and software test of the pseudo-satellite general development and verification platform,including the communication configuration of the baseband and LMS6002 D,the spectral characteristics of the spread spectrum signal and RF output signal when the transmitter is designed,and the AGC module,acquisition,and tracking when the receiver is designed And synchronization and data collection functions and performance testing.The test results verify the correctness and feasibility of the design of the universal pseudo-satellite system development verification platform,and meet the requirements of the design goals.