The Research Of Broadband Spectrum Detection Based On Software Defined Radio

Increasingly scarce spectrum resources restrict the development of wireless communication.With the development of higher frequencies,some scholars try to alleviate the shortage of spectrum resources by improving spectral efficiency.The concept of unlicensed spectrum began acceptable to many countries to solve the deficient of spectrum resources.Unlicensed users can access idle spectrum resources thus achieving the spectrum efficiency upgrade.The spectrum state information is the basis of dynamic spectrum access.So accurate spectrum state is an assurance for normal communication.Thus the selection of spectrum detection during dynamic spectrum access is important.At present,most spectrum detection strategies are fixed band detection which is based on fixed hardware.Those methods cannot achieve multiband or broadband field detection and its application scenarios is limited.This thesis design and implemented the software radio system with the concepts of software defined radio and achieved a variety of spectrum detection algorithm on this system.On the other word the thesis realized the combination of the soft-defined radio(SDR)and the spectrum detection.Our main job is descripted follow:First,author given a detailed theoretical analysis and performance analysis about energy detection,matched filtering and cyclostationary detection.And according the performance and precision of three detection algorithm,the thesis given every algorithm's usage scenarios.Also the best theory threshold algorithm is given.Then SDR hardware designed with AD9361 and FPGA as the carrier of spectrum detection algorithm is given.Along with the hardware platform,the design of the communication protocol which used to the parameter setting between PC and hardware make the data transform easier.Besides hardware platform another part of SDR is the design of the human-machine interface.The Interface improves and integrates the entire SDR system operation process.As the foothold of spectrum detection and system testing,it is an import way to show result and SDR communication configuration.Finally,this thesis gives the design and complement of three algorithm based on the software and hardware platform.For the purpose of spectrum detection algorithms' testing and performance verification,this thesis achieved BPSK signal and OFDM signal.The thesis completed the process of SDR,spectrum detection algorithm and human-machine interface.The system achieved a good performance with the integrating the SDR and spectrum detection.The design and analysis of this system has a greater significance in future development and application of unlicensed spectrum.