Physical-layer key generation (PKG) based on channel reciprocity has recently emerged as a new technique to establish secret keys between devices. Most works focus pairwise communication scenarios with single or small-scale antennas. However, the fifth (5G) wireless communications employ massive multiple-input multiple-output (MIMO) support multiple users simultaneously, bringing serious overhe...

Intelligent reflecting surface (IRS) is a promising technique to extend the network coverage and improve spectral efficiency. This paper investigates an IRS-assisted terahertz (THz) multiple-input multiple-output (MIMO)-nonorthogonal multiple access (NOMA) system based on hybrid precoding with presence of eavesdropper. Two types sparse RF chain antenna structures are adopted, i.e., sub-connecte...