Design And Implementation Of The Communication Platform Based On USRP

With the increasing number of wireless devices,the higher and greater demand for wireless communications and mobile communications technology,people are already aware of the lack of resources and poor allocation of radio spectrum policy issue has become more prominent,so how to improve the spectrum resource utilization become a hot research,which put forward higher requirements of the software defined radio technology.The software defined radio,as one of the key technologies of modern communication,the research and promotion can realize intelligent radio and accelerate the development and application of wireless communication technologies.But most university are confined to the theory research and simulation,there is a lack of communication systems and experimental platform for testing and validation algorithm in a real environment,it has important implications for further research and design and implementation of the communication system platform based on software defined radio.This article designed a communication system based on OFDM modulation,while an improved QAM modulation to reduce the PAPR of the OFDM system.The main contents and work of this paper are as follows:Firstly,the background,status and practical significance summary of the communication system based on software defined radio,also introduced software defined radio related content,including its definition,characteristics,key technology and application development.Determine the main content and objectives of this paper based on the background and status.Secondly,the solutions,functions and algorithms of the communication platform are introduced,and designed the transmitter and receiver of the communication platform based on LabVIEW software and NI-USRP hardware platform,including the design of the transmitter and receiver of OFDM communication system with the functional design of transfer text,images,video data,introduce energy detection and signal modulation recognition algorithm,then proposed an improved QAM modulation scheme,which applied to reduce the PAPR of the OFDM system that can be demonstrated with simulation,and designed the additional features to achieve the spectrum sensing,signal modulation recognition,multi-modulation signal Transceiving,these features allow the people who use the communication platform have a further understand for digital communication related contents and the main technology,also further research can be tested.Finally,build a test environment of communication platform,and make a design that use STC12C5A60S2 to control four 1.2G wireless video transmission unit to simulate the licensed users,and the simulator of licensed users can be connected to a PC via a serial cable,controlled via the communication platform software,two NI-USRP as the transmitter and the receiver respectively,connected to the PC via gigabit switch,and then complete all the test and validation of the features of the actual software radio communication platform in a laboratory environment.