Based Aos Lunar Exploration Communication System Design And Research

The thesis takes the exploration project of the moon in our country as the background and does research work on the data transmission technique between lunar rover and ground station. According to the AOS standard raised by CCSDS, the whole AOS system is designed including the core part made up of high-speed multiplexer/demultiplexer, up-channel multiplexer/demultiplexer, lunar rover control data up-channel multiplexer/demultiplexer and lunar rover image data down-channel multiplexer/demultiplexer.High-speed multiplexer/demultiplexer betakes Stratix FPGA chip to combine or distribute ten signals of different sources and different rates including 320 Mbps high-speed signal so that multi-channeled dynamic data can be transmit transmitted through one physical channel. Up-channel multiplexer/demultiplexer makes use of Cyclone FPGA chip to transmit seven data of different sources including the two channel 2.5Mbps data and the five RS-232 to the space shuttle providing Internet service. The lunar rover control data up-channel multiplexer/demultiplexer transmits the control data to control the lunar rover. The lunar rover image data down-channel multiplexer/demultiplexer transmits the pictures taken by video camera on lunar rover to ground station. The lunar rover wireless orientation system is added to the whole system by which the precise location will be ascertained through measuring the distance and directional angle relative to lunar rover.At last through debugging and testing it is proved that the rate of high-speed multiplexer/demultiplexer can reach to 480Mbps and duplicate the use of multi-channeled signals. The rate of up-channel multiplexer/demultiplexer can attain to 16Mbps, at the same time transmit internet data and five low-speed serial data. The rate of lunar rover control data is 250 Kbps, which is able to control the movement of lunar rover. The rate of lunar rover image rate is up to 86 Kbps, and thus the image is clear and fluent. The precision of lunar rover distance measurement is 1m, and directional measurement less than 20mrad. All of the targets satisfy the requirements of the design, and the system is reliable and stable.