Secure transmission method based on relay strategy selection and resource allocation in relay OFDM (Orthogonal Frequency Division Multiplexing) network

Abstract

The invention discloses a secure transmission method based on relay strategy selection and resource allocation in a relay OFDM (Orthogonal Frequency Division Multiplexing) network. A communication system model employed by the method comprises a sending node S, N destination receiving nodes (D <1>...D <N >), an eavesdropping node Eve and K relay nodes. The method comprises the steps of for data transmission of each time, in a second time slot, after relay strategy selection and resource allocation, sending data to the relay nodes by the sending node S; and in a second time slot, selecting one of the K relay nodes as a forwarding node to forward the data received in the first time slot to the destination node D, and moreover, eavesdropping information sent to N users by the eavesdropping node Eve. Compared with traditional modes of merely employing AF (Amplify-and-Forward) or DF (Decode-and-Forward), the method has the advantages that a lower private interruption probability is obtained in a relay strategy selection mode, and the performance difference between the method and the two traditional modes is more remarkable under a high signal to noise ratio.

Description

Technical field: [0001] The invention belongs to the technical field of physical layer security in a relay OFDM network, and in particular relates to a secure transmission method based on relay strategy selection and resource allocation in a relay OFDM network. Background technique: [0002] At present, Orthogonal Frequency Division Multiplexing (OFDM) technology is widely used in various wireless communications due to its high spectrum utilization rate, strong anti-multipath fading ability, and ability to provide users with high-speed data services. system. In order to improve the security of the OFDM system, the traditional method is to use the key encryption mechanism to encrypt the information. However, with the improvement of terminal processing capabilities, the design, distribution and management of keys by traditional key encryption mechanisms have become more difficult, and the implementation has become increasingly difficult. Therefore, there have been many liter...

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Problems solved by technology

[0003] Because of the advantages of relay technology in physical layer security technology, some scholars have studied the eavesdropping channel model under relay OFDM network, and the research shows that the relay OFDM network security throughput can be obtained through relay selection, resource allocation and other technologies However, there are two problems in this research. The first problem is that maximizing the security throughput of multi-user relay OFDM network does not take into account the fairness of multi-user scheduling, which may cause users with good channel status to occupy the spectrum all the time. Users with poor resources and poor channel conditions cannot access the network for a long time. The second problem is that most of the existing relay OFDM nodes only use AF or DF relay protocol, and the performance of DF relay protocol is poor under low signal-to-noise ratio. Although the forwarding method of the AF relay protocol is relatively simple, the relay node also amplifies the noise signal, which is not conducive to the correct reception of data by the user.

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