Physical Layer Security Of Cooperative Communication

Wireless cooperative communication can increase the communication system capacity and improve the physical layer security performance.The compressed sensing theory,based on the sparsity and compressibility of signal,can reconstruct the signal with fewer measurements.We analyzed physical layer security performance of cooperative communication and compressed sensing theory with multi-sources and multi-relay nodes communication system.We have analyzed amplify-and-forward and quantize-and-forward strategies.Under these two strategies,the signal which change in three stages of compressed sensing has been given out.The channel matrix is a part of the measurement matrix of compressed sensing.The physical layer security performance has been evaluated from reconstruction performance at destination and eavesdroppers.In addition,the impacts of different sparsity,the number of relay nodes and eavesdroppers,the distortion of channel estimate and signal-to-noise ratio to system reconstruction performance have also been analyzed.The simulation results show that it is very difficult for eavesdroppers to reconstruct the original signal,while the destination can recover the original signal based on the channel matrix.Based on discrete Fourier transform,we have also proposed a method of constructing a redundant dictionary and derived the forms of extension Fourier dictionary,aliasing Fourier dictionary and redundant Fourier dictionary.In addition,the sparse representation of signal and reconstruction performance under different dictionaries have been analyzed and compared by the simulation.The simulation results show that the redundant Fourier dictionary is the most effective one.