A Survey of Physical Layer Security Techniques for 5G Wireless Networks and Challenges Ahead (1801.05227v1)

Abstract: Physical layer security which safeguards data confidentiality based on the information-theoretic approaches has received significant research interest recently. The key idea behind physical layer security is to utilize the intrinsic randomness of the transmission channel to guarantee the security in physical layer. The evolution towards 5G wireless communications poses new challenges for physical layer security research. This paper provides a latest survey of the physical layer security research on various promising 5G technologies, including physical layer security coding, massive multiple-input multiple-output, millimeter wave communications, heterogeneous networks, non-orthogonal multiple access, full duplex technology, etc. Technical challenges which remain unresolved at the time of writing are summarized and the future trends of physical layer security in 5G and beyond are discussed.

• The paper presents a comprehensive survey of physical layer security methods that leverage channel randomness to secure 5G communications.
• It reviews advanced coding schemes, massive MIMO techniques, and mmWave strategies, supported by numerical analyses of secrecy performance.
• The study identifies emerging challenges such as imperfect CSI and active eavesdropping, setting clear directions for future research.

Overview of Physical Layer Security Techniques for 5G Wireless Networks

The paper provides a comprehensive survey of physical layer security (PLS) techniques tailored for the evolving landscape of 5G wireless networks. It addresses 5G’s technical demands and corresponding security challenges by introducing novel methodologies rooted in information theory. The focus is on leveraging the inherent randomness of transmission channels to ensure data confidentiality and integrity at the physical layer, distinguishing it from traditional cryptographic techniques reliant on computational complexity.

Key 5G Technologies and PLS

The survey highlights several 5G technologies where PLS is being integrated:

• Physical Layer Security Coding: The work reviews advancements in LDPC codes, polar codes, and lattice codes. Specific emphasis is placed on overcoming the challenges of designing practical coding schemes for secure communications that can be implemented in real-world 5G systems.
• Massive MIMO: This section discusses the potential of deploying extensive antenna arrays to enhance spatial diversity, thus bolstering security against passive and active eavesdroppers. The survey reviews multiple studies that propose strategies involving matched filtering and artificial noise (AN) to safeguard communications.
• Millimeter Wave Communications: Given that mmWave technology offers high bandwidth but suffers from significant propagation losses, it provides a ripe area for security research. PLS techniques that exploit unique propagation models of mmWave are outlined, including the use of beamforming to mitigate eavesdropping risks.
• Heterogeneous Networks: The paper discusses the layered structure of heterogeneous networks and the unique security threats they pose. It emphasizes devising secure transmission schemes that account for cross-tier interference and user node dynamics.
• Non-Orthogonal Multiple Access (NOMA): The work addresses the security implications of NOMA's simultaneous transmission strategy. It outlines strategies for enhancing security under heterogeneous user requirements and varying channel conditions.
• Full Duplex Technology: Full duplex systems allow simultaneous transmission and reception, doubling potential network capacity. The survey explores strategies where full-duplex nodes use self-interference cancellation to manage security threats, including eavesdropper jamming.

Numerical Results and Strong Claims

The paper emphasizes diverse case studies and numerical evaluations affirming PLS strategies' efficacy. Notable is the examination of secrecy outage probabilities and security capacities in various 5G architectures, underscoring PLS's potential to significantly outperform conventional security approaches when optimized for specific 5G scenarios.

Research Challenges and Future Directions

While the survey provides an exhaustive snapshot of current research, it also identifies unresolved challenges:

• The need for advanced coding schemes capable of achieving robust secrecy without perfect CSI.
• Developing unified secure communication protocols that adapt seamlessly with 5G's heterogeneity and evolving standards.
• Addressing active eavesdropping and pilot contamination in massive MIMO setups, especially within the highly dynamic environments anticipated for 5G.

Conclusion

This paper is pivotal for researchers aiming to delve into the intersection of physical layer techniques and 5G security. It not only maps the current landscape but also sets a trajectory for future explorations. The advancement of PLS will play a critical role in securing the communication backbone of next-generation networks by addressing both theoretical constructs and practical implementations. As 5G technology matures, the integration of PLS is imperative for maintaining robust, scalable, and secure wireless communication infrastructures.