Research On Real-time ADS-B Digital Receiving System Based On FPGA

Automatic Dependent Surveillance – Broadcast technology is a new air traffic control technology of modern integrated advanced wireless data communication technology,satellite positioning and navigation information transmission technology,automatic monitoring technology and related technologies in one,which is a kind of navigation monitoring technology being actively promoted by the International C ivil Aviation Organization monitoring.This paper first analyzes the shortage of the existing technology of ATC and the advantages of the ADS-B technology.The related background of ADS-B technology and the current of ADS-B technology at home and abroad research status and development trend is introduced,shows the ADS-B has important research value.Through the detailed elaboration and comparative analysis of the three data chains mainly used in ADS-B,it highlights the unique advantages of the 1090 ES ADS-B data chain;Through briefly illustrate simulation information transmission in wireless communication syste ms and digital information transmission system,highlight the advantages of digital information transmission system,which show that the system adopted by the technical relative to other system has a unique advantage.This paper introduces a digital processing system for ADS-B receiver based on FPGA+ARM architecture,which emphasizes the introduction of the digital demodulation process of 1090 ES ADS-B data link in FPGA.Combined with the IP macro with Quartus ?,this paper adopts digital quadrature demodulation algorithm to demodulate PPM-coded pulse sequence baseband signal of ADS-B message from the medium frequency ADS-B signal,then through against narrow pulse and dynamic threshold process,results the PPM-coded pulse sequence of ADS-B message by threshold comparator.Then through preamble pulse detection,demodulates ADS-B message from the PPM-coded pulse sequence of ADS-B message;ADS-B message data such as the longitude,the latitude and the altitude flight information is analysed out in N ios II,and then sent to the PC software,which to display the information about the planes detected.In the ADS-B receiver based on FPGA implementation and testing process,the related module of the system,such as glass steel 1090 MHz omnidirectional antenna,dual-channel 1090 ES receiver module,digital demodulation and decoding board based on FPGA are described in detail introduced.At the same time,this paper explains the process of digital quadrature demodulation algorithm,observes demodulation effect of the signals related through the tool of Signal Tap II in Q uartus II,and achieves the simulation result of against narrow pulse and dynamic threshold processing through the Model Sim simulation software,finally does the relevant test to the entire system through t he test tools.