A Dual-Channel Directional Modulation System Based on Four-Dimensional Antenna Array

Abstract

The invention discloses a dual-channel directional modulation system based on a four-dimensional antenna array. Its basic structure includes antenna array, radio frequency modulation switch, power division network, local oscillator source, switch management system, sequential memory, baseband signal source 1, baseband signal source 2 and other devices. The biggest innovation of the present invention is that in the absence of a phase shifter, only using a radio frequency modulation switch, the directional modulation and secure communication of two signals in space at the same time are realized, and the transmission direction of the signal can be adjusted by changing the switch sequence . The present invention can use BPSK, QPSK, QAM and other modulation modes, and has good secret communication effect. Compared with the existing security system based on four-dimensional antenna array, this method has the characteristics of simple structure, lower cost, and flexible and convenient adjustment. The invention is used in a wireless communication system.

Description

technical field [0001] The invention belongs to the field of wireless communication, and particularly relates to two-way directional modulation and secret communication by using a four-dimensional antenna array. Background technique [0002] The traditional wireless communication system is based on key encryption, and its security depends heavily on the complexity of the key, which has gradually exposed its security risks. Different from the traditional high-level key encryption technology, the most notable feature of physical layer security is that it does not require complex digital keys to encrypt private information, but studies the security of information transmission from the perspective of information theory, fully utilizing the physical layer of wireless channels. Layer characteristics, including fading, noise and interference, etc. to achieve secure communication, and does not require additional consumption of spectrum resources. Directional modulation, as an emerg...

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Problems solved by technology

[0003] Saad Mufti et al. introduced a dual-channel directional modulation using only phase control in their paper titled "Dual Channel Broadcast using Phase-Only Directional Modulation System" published in the 2018 IEEE International Symposium on Antennas and Propagation & USNC / URSI National Radio Science Meeting system, but the use of a large number of phase shifters will increase the cost of the system, and the transmission rate will be limited to a certain extent; Southeast University discloses a direction modulation method using random perturbation of unit antennas in CN103701514, by randomizing unit antennas to transmit weighting coefficients, resulting in Distortions of constellation points in undesired directions also vary randomly in the absence of noise

But this method can't realize multi-channel confidential communication at the same time; Xi'an Jiaotong University discloses a wireless communication network joint signal feedback and artificial noise physical layer security communication method in CN106131824A, this invention interferes with illegal eavesdroppers by introducing artificial noise correct information, but this method does not consider the implementation of multi-channel signals, and needs to use a phase shifter to change the direction of signal transmission; the University of Electronic Science and Technology of China announced a security communication system and method based on a four-dimensional antenna array in CN102857280, but its Only one-way signal transmission and secure communication can be realized, and the transmission direction of the signal cannot be adjusted arbitrarily

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