Tag-Based Physical Layer Authentication over a Nakagami-m Block-Flat Fading Channel: Theory and GNU Radio Simulations for IIoT

This paper investigates the impact of a Nakagami-m block-flat fading channel on the superimposed-tag (SUP) physical layer authentication (PLA) scheme. Semi-analytical expressions for the probability of false alarm (PFA) and the probability of authentication (PA) are derived. A simulation framework for wireless communication implementing PLA on the open source software GNU Radio is also proposed. The modularity of GNU Radio allows to adapt the framework to other PLA schemes. We show in this paper that theoretical predictions and simulation results are matching together. We demonstrate that severe fading requires higher tag power allocation to maintain reliable authentication, at the expense of data signal power. These findings emphasize the need to adapt the SUP scheme to changing channel conditions to ensure robust and efficient authentication. However, increasing tag power allocation increases data bit error rate (BER), decreasing therefore PA. This highlights the existence of an optimum tag power allocation to maximize PA.