Physical Layer Authentication Enhancement Using Two-Dimensional Channel Quantization

A novel physical layer authentication enhancement scheme is proposed in this paper by integrating multipath delay characteristics of wireless channels into the channel impulse response (CIR)-based physical layer authentication framework. In order to simplify the decision rule for authentication, a two-dimensional (2-D) quantization method is developed to preprocess the channel variations. More specifically, two one-bit quantizers are used to quantize the temporal channel variations in the dimensions of channel amplitude and path delay, respectively. Under a simple hypothesis testing, a new test statistic is developed based on the sum of outputs of the two quantizers. For performance analysis, false alarm rate (FAR) and probability of detection (PD) are defined based on the developed test statistic, and their closed-form expressions are derived as well. An optimization problem is defined for finding optimal parameters of the proposed scheme based on exhaustive search method. Monte Carlo simulations are utilized to evaluate the performance of the proposed scheme. Compared with other existing method in the literature, the proposed scheme outperforms significantly in spoofing detection.