Lightweight Physical-Layer Security Primitives for 5G-and-Beyond Wireless Communications
| dc.contributor.advisor | Chi, Taiyun | en_US |
| dc.creator | Zhou, Qiang | en_US |
| dc.date.accessioned | 2025-05-29T20:03:40Z | en_US |
| dc.date.created | 2025-05 | en_US |
| dc.date.issued | 2025-04-25 | en_US |
| dc.date.submitted | May 2025 | en_US |
| dc.date.updated | 2025-05-29T20:03:40Z | en_US |
| dc.description.abstract | The development of 5G-and-beyond wireless communication represents a major transition toward faster, more intelligent, and more flexible connectivity. Compared with previous generations, 5G-and-beyond systems are designed not only for higher data rates and larger capacity, but also for lower latency, enhanced intelligence, and broader applicability. These capabilities enable a wide range of mission-critical applications, such as immersive AR/VR, intelligent transportation, remote robotic surgery, and drone-assisted communication, where communication quality is tightly coupled with safety, efficiency, or privacy. However, the open nature of wireless propagation also introduces significant security concerns. In particular, as wireless transceivers become more mobile, autonomous, and distributed, it becomes increasingly difficult to verify their identity and prevent eavesdropping. These concerns raise new requirements for the transmitter (TX), which must be able to identify itself as a legitimate source and prevent sensitive information from leaking to unintended receivers. Traditionally, wireless security is achieved through digital cryptography. Although effective in many scenarios, cryptographic methods face four limitations when applied to future systems: (1) the added power and latency overhead becomes problematic for real-time bit-wise encryption, (2) key management becomes complex and power-hungry, and (3) physical signal leakage itself is not protected by encryption. To address these issues, physical-layer security (PLS) has gained increasing attention. By embedding security directly into the physical behavior of the TX, such as frequency, phase, amplitude, or time, PLS enables protection without relying on high-level cryptographic protocols. These techniques can be implemented with minimal latency, power, and area overhead, making them suitable for 5G-and-beyond systems where both performance and security are critical. This thesis focuses on low-overhead, TX-based physical-layer security techniques that address two major security requirements: (1) identification of TX to the receiver, and (2) prevention of wireless eavesdropping. Three system-level designs are proposed, each implemented with custom application-specific integrated circuit (ASIC) TXs and modules, and demonstrated through measurement. The first TX design addresses the identification problem. We propose a physical-layer identification TX that incorporates a digital physically unclonable function (PUF) to control its spectral regrowth. This creates a unique RF fingerprint (RFF) for each TX, beyond what is achievable with intrinsic process variation alone. A 2.4-GHz prototype is implemented in GlobalFoundries 45-nm CMOS SOI process with 4.7 dBm output power and 36% efficiency. Measurement results show significant improvement in RFF stability, uniqueness, and dynamic range compared to prior work. On top of it, we further enhance the identification performance with feature extraction and identification model. We develop a lightweight neural network that extracts PSD features from TX signals and performs device identification. The model is optimized for low-power implementation and works seamlessly with the proposed hardware. In measurement, 240 devices are identified with over 99% accuracy, and 40 devices at unseen distance achieve over 95%, demonstrating strong generalization and robustness under various conditions. The second TX design focuses on preventing sidelobe eavesdropping. We present a mm-Wave antenna subset modulation (ASM) TX operating at 28 GHz. By randomly selecting antenna subsets at the symbol rate, the transmitted I/Q symbols are scrambled outside the main direction, preventing eavesdropping without degrading performance in the desired direction. The ASIC is integrated with on-board antennas and includes a high-speed on-chip true random number generator (TRNG) for secure and unpredictable antenna selection. The system supports 1.2-Gb/s 64-QAM communication with ±2° information beamwidth and maintains high EVM performance. This work highlights the great potential and practicality of integrating ASM technology into future radios. In summary, this thesis proposes and demonstrates three low-overhead PLS techniques at the transmitter level, targeting future communication systems with tight constraints on power, latency, and security. These methods provide a practical and efficient way to enhance wireless security without relying on complicated cryptographic operations, and can serve as a complementary layer of protection in 5G-and-beyond wireless networks. | en_US |
| dc.embargo.lift | 2026-05-01 | en_US |
| dc.embargo.terms | 2026-05-01 | en_US |
| dc.format.mimetype | application/pdf | en_US |
| dc.identifier.uri | https://hdl.handle.net/1911/118440 | en_US |
| dc.language.iso | en | en_US |
| dc.subject | 5G-and-beyond, wireless communication, physical-layer security, integrated circuit, identification, eavesdropping | en_US |
| dc.title | Lightweight Physical-Layer Security Primitives for 5G-and-Beyond Wireless Communications | en_US |
| dc.type | Thesis | en_US |
| dc.type.material | Text | en_US |
| thesis.degree.department | Electrical and Computer Engineering | en_US |
| thesis.degree.discipline | Electrical & Computer Eng. | en_US |
| thesis.degree.grantor | Rice University | en_US |
| thesis.degree.level | Doctoral | en_US |
| thesis.degree.name | Doctor of Philosophy | en_US |