Physical layer security for NOMA schemes in mMTC networks

Abstract

The fifth generation of mobile communications (5G) emerges as the primary key to attend the growing demands of future wireless applications, including ultra high data rates, ubiquitous coverage, a massive number of connected devices and very low latency. In this way, 5G stop being a mere evolution of 4G and becomes the biggest booster of the next industrial revolution. Therefore, it is evident that a huge amount of confidential information will be transmitted by the wireless channels on 5G and future networks, thus providing an effective secure communication is the top priority in the design and implementation of such networks. In this sense, the traditional approach to securing information networks through cryptographic techniques is no longer sufficient to attend the highly diverse requirements of the 4.0 Industry services and applications that will emerge from the 5G network. Given this deficiency, Physical Layer Security techniques has gained growing attention as a complementary solution that offers great advantages for the protection of information in wireless communications. On the other hand, the scarcity and underutilization of radio frequency spectrum is another issue that critical aspect that 5G and future networks need to get around to allow access to a massive number of connected devices. To ensure spectral efficiency, the non-orthogonal multiple access (NOMA) technique has recently been proposed to enable data transmission to different users within the same frequency and time channel. To enable multiple users on the same channel through NOMA, they can be differentiated by different power levels or by codes. From this perspective, the present project aims to evaluate the secrecy performance of a power domain NOMA network, considering that the nearest user is in a safe zone and employs successive interference cancellation (SIC) perfectly. For this purpose, the downlink of a network composed by a base station and two users operating on NOMA will be considered. In addition, it is considered the existence of multiple eavesdroppers in the network, and the secrecy capacity and the secrecy outage probability of network are derived, and the mathematical expressions are validated via Monte Carlo simulations. (AU)