An index-modulated OFDM transmission method against eavesdropping in a multi-antenna system

Abstract

The invention discloses an anti-eavesdropping index modulation OFDM (Orthogonal Frequency Division Multiplexing) transmission method in a multi-antenna system. The method is based on thoughts of orthogonal spatial modulation and artificial noise, and a dimension of an antenna index is added on the basis of a conventional OFDM-IM (Orthogonal Frequency Division Multiplexing-Index Modulation) system.A source node divides original data to be sent into three parts; a first part is called as an antenna index bit and used for determining indexes of at most two activated antennas; a second part is called as a carrier index bit and used for activating a carrier for bearing a signal; a third part is called as a symbol modulation bit and used for mapping the signal to modulate the source node; and according to source node-target node channel state information, the artificial noise is added for a modulation symbol to achieve an anti-eavesdropping effect. A target node respectively adopts an optical maximum likelihood detection algorithm and a suboptimal maximum likelihood detection algorithm based on a log-likelihood ratio. A simulation result shows that a bit error rate of an eavesdropper iskept within a range of about 0.5, and a case that the disclosed scheme can ensure safety of legal transmission is proved.

Description

technical field [0001] The invention belongs to the technical field of physical layer security of a wireless multiple-input multiple-output system, and in particular relates to an index modulation orthogonal frequency division multiplexing transmission method for anti-eavesdropping in a multi-antenna system. Background technique [0002] Multiple-input multiple-output technology transmits multiple data streams while activating all available antennas at the transmitting end, and selects an appropriate precoding matrix to achieve information multiplexing or transmit diversity gain, which can provide higher system capacity and reliability , although this scheme improves the spectral efficiency of the system, the system does not achieve the best energy efficiency, and there are many disadvantages, such as: high synchronization between transmitting antennas is required to meet the requirements of simultaneous data transmission; multiple antennas simultaneously transmit Higher int...

AI Technical Summary

Problems solved by technology

[0002] Multiple-input multiple-output technology transmits multiple data streams while activating all available antennas at the transmitting end, and selects an appropriate precoding matrix to achieve information multiplexing or transmit diversity gain, which can provide higher system capacity and reliability , although this scheme improves the spectral efficiency of the system, the system does not achieve the best energy efficiency, and there are many disadvantages, such as: high synchronization between transmitting antennas is required to meet the requirements of simultaneous data transmission; multiple antennas simultaneously transmit High inter-channel interference is generated during data processing, which increases the difficulty of decoding and increases the complexity of the system; multiple antennas need multiple radio frequency links to work simultaneously, thus increasing the system cost and overhead

Images