The Research Of Spatial Modulation Physical-Layer Security Communication System Aided By Artificial Noise

With the development of wireless communication technology,security issues of wireless communication have become an important factor restricting its development.Physical-layer security is to ensure the safety of wireless communication by designing the self-characteristics of wireless communication system,such as the coding scheme,modulation and transmission mode.As the supplement of conventional encryption protocols,the research of physical-layer security contributes to dealing with the challenges the conventional encryption methods faces.A novel spatial modulation communication security system is proposed by fast switching antennas in this paper.Different from the traditional spatial modulation,the spatial domain information bits are no longer controlled to activate a single antenna in the modulation symbol period,but are mapped to a group of antenna switching modes,and the communication information is transmitted through high-speed switching of multiple antennas.The high-speed switching of the antenna extends the bandwidth of the transmitted signal,so that the signal spectrum is hidden in the background noise,and it is difficult for the enemy to detect and interfere with the normal communication of the desired receiver.Receiver uses the relevant receiving method to accumulate the harmonic signal to recover the original communication information according to the antenna switching sequence agreed by the transmitting and receiving parties.At the same time,the BER and channel capacity of the system are derived.The simulation results verify the correctness of the derivation.We also consider that the eavesdropper obtains the bad situation of the antenna switching sequence,and propose a manual noise-aid fast-switching spatial modulation communication scheme,which interferes with the eavesdropping of the eavesdropping party without affecting the expected receiver receiving the demodulated signal.The simulation results show that the communication signal transmitted in the communication system studied in this paper has has the properties of low probability of detection,low probability of interception.Artificial noise effectively interferes with eavesdropping by the eavesdropper and improves the security of wireless communication signal at the physical layer.