RF Circuit Design Of Ground-based Pseudo Satellite Navigation Base Station

Ground based pseudo satellite navigation technology is a research hotspot in recent years.Four reference stations on the ground are similar to the satellite base station in satellite navigation to send navigation signals to the user receiver.When the user receiver receives the navigation signals,it can solve and complete the positioning.Compared with satellite navigation,the user receiver can get better navigation signals and better position positioning accuracy,Instead of providing users with positioning and navigation technical support in case of satellite navigation failure.In the ground-based pseudo satellite navigation system,in order to improve the positioning accuracy of the system,the groundbased pseudo satellite navigation base station circuit is the core functional circuit of the system,including baseband hardware circuit and RF front-end circuit.At present,the integrated transceiver chip adopted by the industry,including AD93 xx series,is not suitable for the system because it is difficult to extract the accurate carrier phase.In order to promote the application and development of the system,This topic uses discrete devices to design the base station transceiver of ground-based pseudolite navigation system,and develops a high-performance transceiver front-end circuit to ensure the positioning accuracy of the system.In order to maintain the carrier phase consistency of the navigation signal,this research completes the RF circuit design of the base station of the ground-based pseudolite navigation system,including the RF front-end transceiver circuit design and the baseband control interface circuit design.The research contents of this paper are as follows:1.This research introduces the technical research status of ground-based pseudosatellite navigation system at home and abroad,analyzes and defines the design requirements of this research,then studies and analyzes the basic architecture of typical transceiver,designs the base station transceiver architecture suitable for ground-based pseudosatellite navigation system according to its technical characteristics,determines the communication frequency band of transceiver system,and completes the overall scheme of base station RF circuit.2.According to the overall architecture of the RF circuit of the base station,the parameters of the transceiver link system are calculated and analyzed,the link budget simulation analysis is carried out,the index parameters of each module are decomposed and determined,and the cascade simulation is carried out to verify the realizability of the system.According to the budget index parameters of each component module of the RF front end of the link,the core chip and device selection are completed,and the communication interface and power circuit scheme are determined,The RF circuit schematic design and PCB layout design of the base station are completed.3.The prototype of base station circuit is processed and the functional tests of each component module and system are completed.The test results show that the P1 d B output power of base station RF transmitter can be achieved.25 d Bm@2.45 GHz,bandwidth10.23 MHz,carrier phase noise below-120 d Bc@100k Hz The radio frequency receiver sensitivity reaches-80 d Bm,and the base station radio frequency circuit designed meets the requirements of integrated application of the ground navigation system.This research studies and designs the base station RF circuit of the ground-based pseudolite navigation system.By using discrete components and optimizing the RF transceiver circuit design,it has the advantages of low noise,high sensitivity and conducive to maintaining carrier phase synchronization.The hardware implementation of the ground-based pseudolite navigation system provides the core support and effective technical way.