High Speed and Dynamic Switching Type Signal Generation on FPGA for Emulating the Test Signals for Navigation Receivers
In present aviation, navigation is a significant technology. So far, equipped in almost all the civil and military airports, radio navigation system is most widely employed navigation devices in aviation. At present, radio navigation still has priority in short-range navigation of civilian and military aviation in our country. Also, because of the imperfect landing system device in existing aircraft, radio navigation system is of imperative importance in ensuring safety in the Plane’s homing and approaching.
In the real navigation test, to create the RF signal of combined antenna in radio navigation, numerous signal generators are often designed to satisfy performance of navigation system and meet technological requirements. Meanwhile, the signal generator should adjust signal types, parameters and work modes timely according to the navigation system requirements. Thus, signal generator should have the function that signal can be generated flexibly, parameters alter quickly, signal spectrum stay stabilized, and the system is reliable, and so forth.
The proposed system adopts Micro Blaze soft processor as the control core of generator to communicating command with the PC. which can satisfy each requirement in real application of testing and debugging on the navigation.
The significant role in navigation test, radio navigation generator is widely employed in the people/military plane. But traditional equipment composed of analog circuit Presents low correctness and poor reliability. A new type of digital navigation signal generator is designed. It gets data and commands from PC by the Micro Blaze embedded soft processor of Xilinx Company and demodulates information to control FPGA load dissimilar software’s to generate numerous navigation signals, which fully meets general radio navigation system test technical requirements by giving full play to the system hardware and software advantages and fulfilling design targets such as the accurateness, flexibility and expansibility. Thus, offers a new idea for radio navigation system. this generator can be widely applied to debugging use on people/military plane radio navigation.
Using FPGA instead of an ASIC gives also flexibility for reconfiguration, which is a need for the Software Defined Radio (SDR) concept. Modelsim Xilinx edition will be used for simulation. The Xilinx ISE will be used for synthesis; place & route and bit file generation. Xilinx Spartan 3E family FPGA board will be used testing the logic.
Implementation of the project:
In this project we are implementing the analog and digital modulation techniques.
Analog: AM, FM
Digital: Bpsk, Qpsk
The parameters that are need for the modulation like carrier angle, frequency, and kind of mode cane be differed by using the soft core processor called Micro blaze. And the message frequency can be varied by using function generator.