Research On Key Technologies Of Focused Wireless Communication Based On Software Radio Platform

In wireless communications,the unique characteristic "space-time synchronous focusing" and "super-resolution focusing" of Time Reversal(TR)technology can compress the multipath channel delay spread of propagation and increase the capacity of wireless communication channels by making full use of the space resources.With the development of spacecraft technology,how to achieve high reliability in the cabin,high channel capacity and multi-user for the wireless communication has become a research hotspot at home and abroad.Therefore,this paper proposes a focused wireless communication technology solution for the purpose of improving the capacity of wireless communication channels and the amount of users for complex electromagnetic scattering environments in spacecraft cabins,which is based on software radio platforms and maked full use of Time Reversal techniques.In this paper,the in-depth research on the key technologies and characteristics of focused wireless communications was conducted.First,the wireless communication environment in the spacecraft cabin is analyzed,and a focused wireless communication scheme is proposed for the multi-path delay expansion of the complex electromagnetic scattering environment in the cabin.The principle of focusing wireless communication scheme is analyzed theoretically,which demonstrates that the focused wireless communication system has the characteristics of time focusing and spatial focusing.Because of its unique time focusing feature,the focused wireless communication can make full use of the multipath effect to compression multipath delay spread and improve the signal-to-noise ratio,with the result of increasing the channel capacity.On the other hand,the feature of spatial focusing is a powerful theoretical basis for greatly increasing the number of users.Therefore,the focused wireless communication scheme provides an effective solution to improve the reliability of wireless communication system and increase the number of users in the complex electromagnetic scattering environment.Second,the simulation model of focused wireless communication system which transimit the time domain narrow band signal is built.Aiming at the problem of carrier frequency offset,which is caused by the multipath wireless channel fading and the latch precision,the anti-carrier frequency offset performance of the focused wireless communication system is simulated and analyzed.The simulation results proved that the focused wireless communication system can separates the carrier frequency signal from the useful signal with its unique time focusing feature,with the result of improving the system performance of anti-carrier frequency offset.Finally,the focused wireless communication system model is designed based on simulink.With the use of metal cavity instead of spacecraft cabin to simulate the complex electromagnetic scattering environment,the focused wireless communication experiment platform was successfully set up.The experimental results show that the focused wireless communication system can resist the carrier frequency offset and has the characteristics of anti-multipath delay propagation.This study provides a very reference design for wireless communication in complex electromagnetic scattering environment such as spacecraft cabin,which has profound significance for the development of spacecraft technology.