Multicast method and device based on physical layer security transmission

Abstract

Embodiments of the invention provide a multicast method and device based on physical layer security transmission. The method comprises the following steps of estimating channel state information of each multicast user according to a pilot frequency training sequence; when the first number is smaller than the second number, acquiring secrecy capacity according to the estimated channel state information, determining a target multicast user from the multicast user corresponding to the acquired maximum secrecy capacity, and determining sub-carriers corresponding to the maximum secrecy capacity astarget sub-carriers; respectively loading the target sub-carriers into a null space of a main channel corresponding to the target multicast user according to the estimated channel state information inorder to obtain a target channel; and correspondingly introducing artificial noise into each zero space, superposing the artificial noise and data to be sent, and sending the superposed signal through the target channel of each target multicast user. According to the scheme provided by the embodiments of the invention, when different secret QoS requirements of each user in a multicast group are ensured, the correctness of the data can be guaranteed.

Description

technical field [0001] The present invention relates to the technical field of secure multicast transmission in wireless communication, in particular to a multicast method and device based on physical layer secure transmission. Background technique [0002] With the development of broadband wireless communication technology, 5G network is evolving in the direction of diversification, broadband, integration and intelligence. Multimedia Broadcast / Multicast (MBMS, Multimedia Broadcast Multicast Service, multicast for short) technology based on OFDMA (Orthogonal Frequency Division Multiple Access) can use the same time-frequency resource to transmit the same information to multiple users. business. Since there are differences in wireless channels between the transmitting end, that is, the base station end, and each user, the wireless channel information between the transmitting end and all users needs to be considered overall in multicast transmission. In traditional multicast...

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Problems solved by technology

Therefore, the traditional multicast cannot make full use of the receiving ability of each user, the multicast transmission rate is very low, and the throughput performance of the multicast system is poor.

[0003] In order to meet the QoS requirements of multicast users and improve system performance such as multicast system throughput, a multicast method for secure physical layer transmission is proposed. This method uses multiple antennas at the sending end to send and receive data. Party is a multicast user, and each multicast user uses a single antenna to send and receive data, wherein, after the base station obtains the channel state information of each multicast user, that is, a legal user, through the pilot training sequence, the main channel of the legal user Add artificial noise to the eavesdropping user, so that the eavesdropping user is disturbed by the artificial noise and cannot receive the correct data

Although this method can safely transmit data, it is difficult to generate effective artificial noise in the orthogonal space of channel vectors of many legal users when the number of antennas at the transmitting end is lower than that at the receiving end. It will destroy the signal received by legitimate users, and the correctness of the received data cannot be guaranteed

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