An Improved Method for Improving the Stable Performance of Communication System

Abstract

The invention discloses an improved method for improving the stability property of a communication system, belonging to the technical field of communication. The improved method comprises the steps of: determining a parameter, a determining an optimization program, simplifying the optimization problem, introducing a slack variable, transforming a half-infinite limit condition into a linear matrix inequality, obtaining a final form of the optimization problem, proving that the solution is an optimal solution, solving an optimal sending power popt, and outputting the optimal sending power popt. According to the improved method, on the premise of considering that the channel state information of a wiretap channel is not completely known, an optimal scheme is re-designed, therefore, the stability property of secret communication is improved. Under the condition of realizing that the state information of the wiretap channel is not completely known, a manual noise covariance matrix and a transmission beam forming vector are combined for optimization design, thus the stability of the secret communication is improved. Compared with the condition of known channel state information, the improved method has remarkable advantages on the stability of the whole system.

Description

technical field [0001] The invention relates to a beamforming and artificial noise joint optimization method for improving the stability performance of a secret communication system under the condition that the state of an eavesdropping channel is not completely determined, and belongs to the technical field of communication. Background technique [0002] Due to the broadcast characteristics of wireless communication devices, confidentiality becomes the most basic issue in wireless communication. Traditionally, secure communication has been achieved through the use of cryptographic systems, like encryption. On the other hand, from the perspective of information theory, many studies have proved that reliable and secure communication can be achieved without adding keys, that is, physical layer security. [0003] Physical-layer secrecy was first proposed by Wyner from the perspective of information theory. To achieve physical layer security, it is mainly to use the physical c...

AI Technical Summary

Problems solved by technology

There are two main ways to add artificial noise: one is to place artificial noise directly in the null space of the main channel, which will not affect the main channel but can attenuate the eavesdropping channel, but it is not optimized and the power distribution is unreasonable; One is to jointly optimize the artificial noise covariance matrix and the transmission beamforming vector. Although the algorithm is relatively complex, it can allocate the transmission power reasonably. "Transmission beamforming based on quality of service in the presence of eavesdropping: a Optimization method" [IEEE Trans, Signal Process., vol.59, no.3, Mar.2011.] belongs to this column

However, in practical applications, the specific location (including direction, distance) of the eavesdropping end is not specifically known, that is, its channel state information is not completely known to the transmitting end, or even completely unknown

Therefore, all studies based on the assumption that eavesdropping channel state information is completely known have an ideal background and are of little significance to actual research.

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