Performance Analysis of Artificial Noise-aided Physical Layer Security in Multi-antenna Wireless Networks

Abstract

Wireless communication is the most dynamic and rapidly expanding technology area in the communication industry. Data can be transmitted wirelessly from one location to another without the use of physical mediums like cables or wiring, or other connections. Because of the continued universal development of wireless communication networks, privacy and security concerns have anticipated a greater impact. The broadcast nature of wireless communication makes it vulnerable to security attacks such as data loss, hijacking, and eavesdropping. Conventionally, cryptography-based security solutions have been made where a secret key is generated and shared over the wireless channel. This technique suffers from the problem of key sharing and key management, making the future wireless network create a time delay in operation. The physical layer security (PLS) technique overcomes this problem which is based on Claude Elwood (C.E) Shannon's everlasting information-theoretic security. By using the basic principle of the inherent randomness of wireless channel and noise, then degrading the listening capability of the attacker, without the need for secret key generation security, is achieved. Different physical layer security techniques have been investigated by different researchers. In this thesis, artificial noise-aided (AN-aided) physical layer security technique over the multi-antenna system on Rayleigh fading and additive white Gaussian noise (AWGN) channel in passive eavesdropper scenario performance is analyzed. Transmit beamforming is used for the multi-antenna system, which is two transmit and single receive antenna for both the eavesdropper and the legitimate receiver. The system is analyzed by using binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK) modulation techniques, based on performance evaluation techniques bit error rate (BER) and signal-to noise ratio (SNR), at 20dB SNR and 40% AN, better performance is achieved the legitimate user (Bob with AN) is not affected significantly, while the eavesdropper BER value with AN is increased 140 times at BPSK modulation, and on QPSK modulation only 38 times BER value is increased this making BPSK modulation better. Also, by increasing the number of transmit antennas from two to three and then to four and applying them to transmit beamforming for the two modulation technique and four transmit antennas, for bob without transmit beamforming and eavesdropper with and without transmit beamforming,793 times increased BER value for BPSK and 630 times BER value increase for QPSK. This makes BPSK better