@article{he_chaotic_2025,

title = {Chaotic digital filter-based physical layer security with data-assisted tri-level encryption for heterogeneous access networks},

author = {Jiaxiang He and Roger P. Giddings and Wei Jin and Ming Hao and Jianming Tang},

url = {https://ieeexplore.ieee.org/document/10989603},

doi = {10.1364/JOCN.555584},

issn = {1943-0639},

year  = {2025},

date = {2025-06-01},

urldate = {2025-10-08},

booktitle = {Optical Fiber Communication Conference (OFC) 2025},

journal = {Journal of Optical Communications and Networking},

volume = {17},

number = {6},

pages = {448–458},

abstract = {Due to the increasing demand for robust network cybersecurity, future communication technologies must consider security as a mandatory design feature. However, existing physical layer security techniques can be excessively complex and too expensive to support resource-constrained devices in heterogeneous access networks with high connection densities. To address this challenge, a physical layer security technique employing chaotic digital filters (CDFs) with private security keys is proposed and experimentally validated, for the first time, in a 12 Gbit/s intensity modulation and direct detection optical system with a 25 km standard single-mode fiber. Noise-like private security key-based CDFs have security key-dependent changes in amplitude and phase frequency response, with permutation entropies of textbackslashgt 0.99, thus achieving data-assisted tri-level encryption by directly distorting the data signals, inducing interferences between data signals, and also intensifying the interferences via illegal detections. As CDFs are digitally integrable and offer features of “security-by-design,” “openness-by-design,” and “dynamic security at the traffic level,” the proposed technique facilitates an open and interoperable security solution with the utmost security for heterogeneous access networks.},

keywords = {Bandwidth, Chaotic communication, Encryption, Entropy, OFDM, Optical distortion, Optical fiber sensors, Optical fibers, Optical filters, Security},

pubstate = {published},

tppubtype = {article}

}

@article{sui_ris-assisted_2025,

title = {RIS-Assisted Cell-Free Massive MIMO Relying on Reflection Pattern Modulation},

author = {Zeping Sui and Hien Quoc Ngo and Trinh Van Chien and Michail Matthaiou and Lajos Hanzo},

url = {https://ieeexplore.ieee.org/document/10640072},

doi = {10.1109/TCOMM.2024.3446589},

issn = {1558-0857},

year  = {2025},

date = {2025-02-01},

urldate = {2025-10-08},

journal = {IEEE Transactions on Communications},

volume = {73},

number = {2},

pages = {968–982},

abstract = {We propose reflection pattern modulation-aided reconfigurable intelligent surface (RPM-RIS)-assisted cell-free massive multiple-input-multiple-output (CF-mMIMO) schemes for green uplink transmission. In our RPM-RIS-assisted CF-mMIMO system, extra information is conveyed by the indices of the active RIS blocks, exploiting the joint benefits of both RIS-assisted CF-mMIMO transmission and RPM. Since only part of the RIS blocks are active, our proposed architecture strikes a flexible energy vs. spectral efficiency (SE) trade-off. We commence with introducing the system model by considering spatially correlated channels. Moreover, we conceive a channel estimation scheme subject to the linear minimum mean-square error (MMSE) constraint, yielding sufficient information for the subsequent signal processing steps. Then, upon exploiting a so-called large-scale fading decoding (LSFD) scheme, the uplink signal-to-interference-and-noise ratio (SINR) is derived based on the RIS ON/OFF statistics, where both maximum ratio (MR) and local minimum mean-square error (L-MMSE) combiners are considered. By invoking the MR combiner, the closed-form expression of the uplink SE is formulated based only on the channel statistics. Furthermore, we derive the total energy efficiency (EE) of our proposed RPM-RIS-assisted CF-mMIMO system. Additionally, we propose a chaotic sequence-based adaptive particle swarm optimization (CSA-PSO) algorithm to maximize the total EE by designing the RIS phase shifts. Specifically, the initial particle diversity is promoted by invoking chaotic sequences, and an adaptive time-varying inertia weight is developed to improve its particle search performance. Furthermore, the particle mutation and reset steps are appropriately selected to enable the algorithm to escape from local optima. Finally, our simulation results demonstrate that the proposed RPM-RIS-assisted CF-mMIMO architecture strikes an attractive SE vs. EE trade-off, while the CSA-PSO algorithm is capable of attaining a significant EE performance gain compared to conventional solutions.},

keywords = {Array signal processing, Cell-free massive MIMO, Channel estimation, Chaotic communication, Energy Efficiency, iterative optimization, Optimization, Reconfigurable Intelligent Surfaces, reflection pattern modulation, Spectral efficiency, Symbols, Technological innovation, Uplink},

pubstate = {published},

tppubtype = {article}

}