Method for safely optimizing physical layer in multi-relay cognitive radio network

Abstract

The invention requests for protecting a method for safely optimizing a physical layer in a multi-relay cognitive radio network, and relates to the technical field of cognitive wireless communication systems. For a scene that multiple mutually colluded wiretapping nodes exist in the multi-relay cognitive radio network, the invention provides a safe transmission scheme of a zero-space artificial noise and amplified forwarding (AF) relay beam forming physical layer. Firstly, a system is modelled, and designed into a secrecy rate maximization problem; secondly, due to introduction of a slack variable, the fact that the secrecy rate maximization problem can be converted into the tight and slack problem is proved theoretically; furthermore, joint optimization solution of a relay beam forming weighting matrix and an artificial noise covariance matrix is carried out by utilizing a semi-definite programming method; and finally, due to MATLAB simulative verification and analysis, the secrecy rate of the system can be increased to a great degree.

Description

technical field [0001] The invention relates to the field of cognitive wireless communication, in particular to physical layer security technology in cognitive radio technology. Background technique [0002] Cognitive radio (CR) is an effective method to solve the current shortage of spectrum resources. The innovation of physical layer transmission technology in cognitive radio network provides a wide range of topics and research space for the research of physical layer security. At present, the traditional eavesdropping terminals based on cognitive radio physical layer security selection are all single-antenna, and this model is relatively simple. Moreover, in the existing literature, the methods for designing the transmission covariance matrix of the secondary user sending end are limited, and the complexity is relatively high. [0003] In the Cognitive Radio Network (CRN), the Secondary User Transmitter (SU-Tx) can use the assigned primary The user's band communicates ...

AI Technical Summary

Problems solved by technology

Many literatures do not discuss the existence of relays, and only perform beamforming for the antenna matrix at the transmitting end, without considering another form of adding artificial noise [Xie X Z, Xie C J, Lei W J et al.Improved Transmit Design for Physical Layer Security in Cognitive Radio Networks with Multiple Eavesdropper Base on Semi-Definite Programming[J].Journal of Electronics&Information Technology,2012,34(4):770-775]

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