Performance Evaluation of the MIMO-OFDM System Using Artificial Noise Based on the SDR Platform

Artificial noise is one of the most essential security technologies for signal processing-based physical layer secure transmissions. Fewer studies have examined its reliability in actual communication systems. Utilizing the LabVIEW program development environment and universal software radio peripheral devices, this paper presents a novel software-defined radio (SDR) platform of the AN-assisted multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) system. Particularly, in the practical communication scenarios, larger quantity of testing experiments are carried out to verify the influence of different AN power ratios and antenna number of transceiver devices on the communication performance of the legitimate user and potential silent eavesdroppers. It is discovered that, after adding AN to confidential signals, the bit error rate (BER) of the legitimate user is substantially lower than that of eavesdroppers. Increasing the number of receiver antennas is beneficial to improve the BER performance of legitimate and illegitimate devices. Meanwhile, we find an interesting phenomenon that augmenting the number of transmit antennas solely improves the reception quality of the legitimate user, without exerting a significant impact on eavesdroppers. This paper provides a powerful experimental support for the application of AN in the future communication.