Design On Communication Scheme And Signal Wiretapping Based On Physical Network Coding

With the development of network communication, Network Coding (NC) technology isgradually regarded as the key technique to settle the problem that the communication capacity islimited. After ten years, Network Coding is applied in every domain of communication. In thewireless communication system, Physical Network Coding (PNC) that the NC applies in thewireless communication system attracts all researchers’ attention because it could improve thewireless communication throughout greatly. As a non-cooperator, the paper not only investigatethe problem that how to realize and improve the Physical Network Coding technology inwireless channel, but it also pay more attentions on the method of signal analysis in PNC system.Based on the requirement of task, the paper gives us new schemes to improve PNC efficiency,and establishes the model of eavesdropper to recover the signals blindly.The paper mainly includes five parts in the following,(1) Two-way Relay Channel (TWRC)is our mainly platform in the paper. The paper firstly concludes the principle on design the relaymapping, and designs the relay mapping scheme for QAM Quadrature Amplitude Modulation,and then analyzes the performance of the scheme in the Gauss environment.(2)The paper studieson the scheme of power location to maximum the power utility, when the total power isconstraint. In my paper, we propose a new scheme on power location based on the equal powerlocation scheme and characteristics of PNC, and the method on how to adjust and locate thepower is given in the paper. The simulation result proves that the new scheme improves thetransmission rate by1dB.(3)The paper proposes the Encode-PNC scheme to settleerror-transmission in the PNC scheme. The simulation results imply that the new schemeimproves the communication efficiency.(4)The paper puts forward a improved scheme based thePNC scheme under the principle of maximum efficiency. The new scheme utilizes the idea ofANC (Analog Network Coding) in the slot2of PNC, and could exchange the informationcontinuously.(5)At last, according to the relay mapping, the PNC could sort as finite PNCscheme and infinite PNC scheme. The paper establishes the models of eavesdropper on the PNCscheme respectively, and proposes the methods of signal analysis to recover the informationblindly.We conclude the main contributions of the paper in the following:(1)The paper designs the proper relay mapping scheme for16QAM in the PNC system, andthen analyzes the performance in the AWGN (Additive White Gaussion Noise) channel.(2)The paper improves the scheme of equal power location by adjusting the power when thetotal power is constraint, and proves the new power location scheme could increase the powerutility by1dB.(3)The paper proposes continuous transmission scheme to exchange information based theidea of ANC, and the scheme improves the efficiency greatly by60%when the snr (the ration ofsignal and noise) is5dB.(4)The paper establishes the model of eavesdropper on the PNC scheme based on characters of wireless communication. We apply the ICA Independent Component Analysis technologyto analyze the analog network coding scheme, and obtain the good result. In the digital networkcoding, we process the signal based on the information of encoding and constellation of mixedsignal to recover the information successfully.