Physical Layer Security In Wireless Communication Systems With Multiple Antennas

This paper mainly discuss the problems of physical layer security in wireless communications systems with multiple antennas,and will develop the algorithm designs according to different frequency bands.At conventional communication spectrum,the physical layer security problems have already been well investigated.Therefore,in this paper,I consider the pilot spoofing attack with an active eavesdropper.By launching such attack,the transmitter will wrongly estimate the channel state information(CSI),resulting in the decrease of legitimate transmission quality and even information leakage.In an effort to detect such attack and minimize its damages,I propose a novel random-training-assisted pilot spoofing detection algorithm.According to the results returned by the detector,two enhancement algorithms are proposed,too.When the detector indicates “no pilot spoofing attack”,two enhancement algorithms are proposed: one is the channel estimation enhancement algorithm,which can effectively increase the accuracy of the estimated CSI,the other is the secure transmission algorithm,which can prevent potential information leakage in case of miss detection.Extensive simulation results demonstrate that the proposed pilot spoofing detector can achieve efficient pilot spoofing detection in all cases and its performance is superior to other state-of-the-art detectors.The effectiveness of the two enhancement algorithms are validated,too.On the other hand,with the fifth generation(5G)around the corner,wireless communication has been extended to millimeter wave(mmWave)spectrum,and related researches are abound.However,researches on physical layer security in mmWave multiple-input multiple-output(MIMO)systems,especially secure hybrid beamforming,are still in its early stage.Therefore,in this paper,I proposed the hybrid beamformer design algorithms for codebook-free analog beamformer schemes with low-resolution phase shifters,and codebook-based analog beamformer schemes with high-resolution phase shifters.According to the availability of the eavesdropper's CSI and two different schemes,four algorithms in total are proposed.Extensive simulation results validate the effectiveness of the proposed four secure hybrid beamformer designs.