Adaptive robust zero space projection beam forming method in secure wireless transmission

Abstract

The invention provides an adaptive robust zero space projection beam forming method in secure wireless transmission. The method is composed of three parts: estimation of an arrival angle and a signalto noise ratio, prediction of an angle error range and robust and secure beam forming. In a first time slot, firstly, direction angles of a desired direction and an eavesdropping direction are estimated by a root value multiple signal classification algorithm. Then, singular value decomposition is performed on a covariance matrix of a received signal. Finally, with the aid of the Kcramer's lower boundary formula, the angular error range can be predicted from the estimated arrival angle and the signal to noise ratio. In a second time slot, all the estimated parameters are used for designing a useful signal beam forming vector and a artificial noise projection vector. Compared with the traditional non-adaptive robust method and the non-robust method, the adaptive robust zero space projectionbeam forming method provided by the invention has the advantages of reducing the bit error rate and improving the security rate, so that the system realizes secure wireless transmission.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to an adaptive and robust zero-space projection beamforming method in secure wireless transmission. Background technique [0002] In recent years, the transmission, storage, processing and protection of private information has become an extremely important research hotspot in the field of wireless networks. Due to the broadcast characteristics of wireless transmission, private information is easily eavesdropped by illegal users, which will cause serious security risks to wireless networks. Therefore, it is urgent to design a secure transmission method to protect legitimate users from being eavesdropped. Wyner first studied discrete memoryless eavesdropping channels for secure communication in the presence of eavesdroppers, and proposed the concept of secure rates. Physical layer security can be used to provide another layer of protection on top of traditional encryp...

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Problems solved by technology

[0004] However, previous research work only considers the design of beamforming in two scenarios, that is, perfect orientation angle information and imperfect orientation angle information, but given the error distribution

All these methods are difficult to adapt to changes in channel conditions, and they all ignore the steps of direction angle estimation, signal-to-noise ratio estimation, and angle estimation error range prediction in a practical direction modulation network

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