PHY-Layer Authentication Exploiting Channel Sparsity in MmWave MIMO UAV-Ground Systems

This paper exploits the efficient channel modeling and channel sparsity to propose a novel Physical (PHY)-layer authentication framework for a Millimeter Wave (mmWave) Multiple-Input Multiple-Output (MIMO) Unmanned Aerial Vehicle (UAV)-ground system. Inspired by the Image Processing theory, we first explore a new Laplace prior approach for the efficient modeling of angular-domain mmWave MIMO channels. With the help of the new channel model, we then reveal the channel sparsity in the concerned system exhibiting a nice spatial correlation property. By a joint use of channel sparsity correlation, efficient sparsity feature extraction with Expectation Maximization (EM)/Generalized Approximate Message Passing (GAMP) algorithms and hypothesis testing, we thus devise a new authentication framework for the concerned system. Theoretical performance analysis is also carried out by deriving the closed-form expressions for false alarm and detection probabilities. Finally, extensive numerical results are provided to validate the feasibility of the proposed channel model and the theoretical analysis, as well as to demonstrate the efficiency of the new authentication framework under various scenarios.

I. Introduction

Benefit from their high flexibility and low deployment cost, the Unnamed Aerial Vehicle (UAV)-ground communication systems become highly appealing to overcome the geographical restrictions on communication [1]. In particular, the requirements for the increased flexibility and broad on-demand coverage of 5G and beyond networks can be effectively achieved by deploying a large number of maneuverable and low manufacturing cost UAVs to serve as aerial wireless relays for transferring information in ground communication systems [2]. Moreover, the UAV-ground communication systems integrated with Millimeter Wave (mmWave) Multi-Input Multi-Output (MIMO) technology can offer an ultra-high transmission rate and enhanced reliability, so they can efficiently support some critical applications with high-throughput and low-latency requirements, such as the remote sensing, military supervision and smart cities [3]. To ensure the secure operation of mmWave MIMO UAV-ground systems, identity authentication for a Ground Control Station (GCS) serves as a crucial issue to avoid sensitive data leakage caused by unauthorized access [4].