Physical Layer Authentication of MIMO-STBC Systems Based on Constellation Dithering

Most of the existing physical layer watermarking authentication schemes are based on a single-input single-output system and require pre-issue of shared keys. To address these problems, in this thesis, a physical layer authentication scheme without the distribution keys is proposed based on the constellation dithering physical layer authentication watermarking mechanism with a multiple-input multiple-output (MIMO) system, and space-time block coding (STBC) is used to improve the robustness of transmission. Specifically, the legitimate node obtains channel state information (CSI) through channel probing and couples CSI with the message signal using a hash function to generate an authentication tag, which is then embedded through constellation dithering. The receiver extracts the tag and authenticates it using hypothesis testing. Performance analysis shows that the scheme is resistant to various attacks such as replay, interference, tampering, and forgery. Simulation results show that the use of MIMO multi-antenna diversity with STBC coding technique reduces the bit error rate (BER) of message signals and tag signals and improves the detection rate of legitimate signals.