Hardware Implementation Of LEO Satellite Channel Characteristic Emulation

Wireless communication is a fast-developing direction of scientific research in communication field. Comparing with the terrestrial wireless communication systems, the satellite mobile communication system is always a hotspot and plays an irreplaceable role in military communications, emergency communications and communications in outlands due to its wide coverage and convenience to provide a global service. Among kinds of satellite communication systems, the LEO satellite communication system has less communication delay, less path loss, a more flexible network and a very wide prospect.In order to provide the LEO satellite communication system with a good performance, the important issue is to study the channel propagating characteristic. In developing satellite communication systems and transceivers, it's difficult to have real-time results by using software emluators because of huge computing, and it is expensive to experiment on hired real satellite links. A better solution is developing an LEO satellite channel emluator, which is realized by both software and hardware and can emulate transmission characteristics of satellite mobile channels. The aim of this thesis is realizing an LEO satellite channel simulator, which is used in the satellite constellation emulation system and can emulate real-time channel characteristics of users'link between satellites and mobile terminals at 70MHz in kinds of different environments.This thesis is organized as follows:Firstly, after comparing some widely-used channel models, choose a statistical model that can characterize real satellite channel transmission better as the satellite channel emulator's theoretical model, whose name is LMS (Land Mobile Satellite) modle.Secondly, based on the analysis of LMS model, considering the doppler frequency offset, transmission noise and free space loss, we propose a project of realizing the satellite channel emulator, design the realization techniques of each part of theoretical models and validate the the realization techniques by using QuartusII.In the end, we have accomplished LEO satellite channel emulator by FPGA starter board and some other hardware resources. Channel characteristics emulated by satellite channel emulator can be added on input signal at 70MHz. In this thesis, some test results are presented.