Design And Research Of Software Radio Image Transmission Platform Based On OAM Multiplexing Signal

Due to the rapid development of various wireless communication applications,spectrum resources are increasingly scarce,and the transmission capacity to meet the reliable transmission of communication is far from enough.In order to effectively solve this kind of problem,the vortex electromagnetic wave multiplexing technology with orbital angular momentum(OAM)is applied to the field of wireless communication.Because of its two advantages of efficient spectrum utilization and strong antiinterference in the transmission process,it has great potential and broad application scenarios in the field of wireless communication.At the same time,owing to the good openness and flexibility of software radio,it can be well matched with OAM multiplexing transmission technology to complete reliable information communication.In this paper,the orbital angular momentum technology and software radio technology are combined to build a software wireless system suitable for OAM image signal multiplexing and transmission.The baseband signal processing process of the transmission system is simulated,and the improvement scheme of the system is put forward according to the practical problems in the process of OAM multiplexing transmission.The main research content and innovation of this paper are divided into the following three parts:First of all,this paper chooses the combination of software radio platform and OAM antenna in the construction scheme of the experimental platform.The software of the built system chooses open-source software GNURadio,hardware chooses USRPX310.This paper also introduces the installation and test methods of gnuradio,and proposes a mirror image restoration method for USRP based on the problem of USRP image damage and the rejection of external network access.In order to realize the real-time transmission of short-distance image data based on OAM multiplexing transmission signal,this paper designs the transmission scheme of the digital baseband part of the whole system.The main parameters are written visually in each baseband signal processing module,and the timing simulation of each module is carried out by GNU radio software.So that each module of the system can work normally and interact with each other,and finally realize the function of real-time sending and receiving image data in the simulation level.In the final section,according to the characteristics of the OAM antenna,the OAM signal transmission system can be improved.In order to prove the reliability of the design system,two modulation methods are used to process the signal.The experimental results show that the system can support the modulation signal transmission of DBPSK and DQPSK,to prove that the OAM multiplexing system is more superior and stable,compares the ordinary 2.45G antenna and 5.39 GO AM antenna system superiority.Finally,under the two antennas,the systems designed in this paper can successfully transmit image data,in which the OAM transmission system platform is shorter,the spectral utilization is higher,and the anti-interference performance is stronger.