Mehdi Tafazolli

—In near-field communication (NFC) systems formed by high-frequency bands and extremely large-scale antenna arrays, signal leakage creates vulnerabilities that can be exploited by potential and dynamic eavesdroppers (Eves). Most existing privacy protection approaches rely on prior information, such as Eve's location or channel state information (CSI), which is difficult to obtain in practice. Furthermore, Eve can actively adjust its position to enhance its eavesdropping capabilities. Therefore, we propose a privacy protection approach for NFC systems, which can defend against potential dynamic Eves without prior information about Eve. Specifically, the base station (BS) employs an active obfuscation strategy, injecting deceptive signals while transmitting legitimate signals. To balance privacy protection performance and communication performance, a dynamic multi-objective optimization problem is formulated, which jointly optimizes the transmit power allocation and the spatial focusing position of the deceptive signal. Subsequently, we propose the multi-objective conditioned network (MOCN) algorithm, which learns a conditional policy to obtain the Pareto front. The simulation results show that, the proposed approach improves privacy protection performance by approximately 200% compared to the benchmark algorithm.

White Rabbit (WR) attains sub-nanosecond synchronisation by treating the fibre asymmetry coefficient as a one-time calibration constant, neglecting the thermo-optic dependence of the refractive index on temperature — an effect that grows with link length. We show that for a 150 km link, a fixed asymmetry coefficient introduces a picosecond-scale systematic one-way-delay bias under multi-degree path-averaged drift, scaling linearly with length. We reformulate the WR delay model with explicit temperature dependence, anchoring on the time-invariant-assumed fibre length, so the average fibre temperature drift can be estimated from standard PTP timestamps and folded into the control loop error signal without disturbing phase tracking; a constant-velocity Kalman filter then smooths timestamp noise and predicts the link delay between exchanges. Evaluated against published long-range WR configurations, the algorithm improves long-term time deviations at averaging times above 1000 s under a 5 K peak-to-peak diurnal swing, with the gain widening as the PTP exchange rate is lowered and the prediction step bridges longer gaps. In simulation, the same estimator also recovers an effective path-averaged fibre-temperature drift from timing data alone, suggesting a possible zero-added-hardware sensing by-product rather than a field-calibrated temperature-sensing claim. These results position long-range White Rabbit as a timing infrastructure for deterministic 6G continuum networks, where relaxed timing-message exchange can reduce control overhead while preserving long-term synchronisation stability.

A novel polarization reconfigurable anisotropic dielectric resonator antenna (ADRA) is presented utilizing a new modulation scheme to exploit the degree of freedom in the polarization domain. The ADRA comprises periodic assembly dielectric resonators with two different dielectrics constant, equal in size, a vertically positioned metal strip, one varactor diode, and six PIN diode switches. The modulation scheme utilizes the tilt angle and axial ratio (AR) of a wireless signal to convey additional information, enabling the realization of different working modes ranging from circular polarization (CP) to nearly linear polarization (LP). The proposed modulation scheme yields significantly better bit error rate (BER) performance and higher spectral efficiency in bits/s/Hz/antenna. Additionally, the paper presents an antenna design capable of generating an arbitrary polarization state, highlighting the system benefits of polarization modulation. Post-fabrication, the proposed approach is validated by comparing simulated and measured results. The proposed antenna provides a total efficiency higher than 93% in the desired frequency bands and consistent gain at approximately 7.64 dBi and 7.09 dBi at 3.8 GHz, with the impedance matching bandwidth ranging from 3.53 to 3.90 GHz and 3.56 to 3.91 GHz fully overlapping across all polarization states for the simulated and measured results, respectively. Experimental results affirm the robust performance of the proposed ADRA.