A Noise-Shaped Signaling Method for Vehicle-to-Everything Security

This paper presents a method to improve the Vehicle-to-Everything (V2X) security. With the recent rapid development of communication technology and traffic applications, V2X is recently commercialized and has been growing as a fundamental system for future applications. Because of the high mobility of the vehicles, V2X requires a low latency and high-reliability. However, previous security methods demand a large computational burden and generate high latency owing to complex operations and long additional data bits for ensuing security. To resolve such constraints, an advanced security method ensuring lower latency and higher reliability is required. We propose a noise-shaped signaling method that provides high-level security with low latency for reliable V2X communication. The proposed method encrypts original data symbols to noise-like symbols by applying a noise envelope that consists of Chaotic Random Magnitude Sequence (CRMS) and Chaotic Random Phase Sequences (CRPS). Our method simplifies the sequence sharing process between a sender and an intended receiver by adapting the characteristics of a chaotic dynamic system. Moreover, the proposed method does not demand additional data bits and generate delay because the method only uses simple multiplication and division procedure for data encryption in the physical layer. We analyze our method in depth using extensive simulations and various viewpoints such as error rate, probability of modulation identification. From the simulations, we demonstrate that a malicious adversary cannot comprehend the transmitted symbols and always has the maximum error rate under various network environments and conditions. We also demonstrate how the adversary cannot infer the modulation scheme from the symbols applying the proposed method. After these analyses, we confirm that the noise-shaped signaling method is high-level of secure method with a low latency for V2X communication

Improved Calculation Method of Coupling Factors for Low-Frequency Wireless Power Transfer Systems

The concept of a coupling factor was introduced in International Electrotechnical Commission (IEC) 62311 and 62233 to provide a product safety assessment that considers the localized exposure when an electromagnetic field (EMF) source is close to the human body. To calculate the coupling factors between the human body and EMF source, a numerical calculation should be carried out to calculate the internal quantities of the human body models. However, at frequencies below 10 MHz, the computed current density or internal electric field has computational artifacts from segmentation or discretization errors. Specifically, coupling factors are calculated based on the maximum values, which may include computational artifacts due to abnormal peaks. In this study, we propose an improved calculation method to remove computational artifacts by applying the 99.99th percentile in calculating the coupling factors without underestimation. The performance of the proposed method is verified through a comparison based on various human body models with wireless power transfer (WPT) systems and compliance with the reference levels and basic restrictions. The results indicate that the proposed method can provide uniform coupling factors by reducing the computational errors by up to 65.3% compared to a conventional method

Wireless Torque and Power Transfer Using Multiple Coils with LCC-S Topology for Implantable Medical Drug Pump

In this paper, we propose a method of wirelessly torque transfer (WTT) and power (WPT) to a drug pump, one of implantable medical devices. By using the magnetic field generated by the WPT system to transfer torque and power to the receiving coil at the same time, applications that previously used power from the battery can be operated without a battery. The proposed method uses a receiving coil with magnetic material as a motor, and can generate torque in a desired direction using the magnetic field from the transmitting coil. The WPT system was analyzed using a topology that generates a constant current for stable torque generation. In addition, a method for detecting the position of the receiving coil without using additional power was proposed. Through simulations and experiments, it was confirmed that WTT and WPT were possible at the same time, and in particular, it was confirmed that WTT was stably possible

Minimizing Leakage Magnetic Field of Wireless Power Transfer Systems Using Phase Difference Control

In this paper, we propose a method to reduce the leakage magnetic field from wireless power transfer (WPT) systems with series–series compensation topology by adjusting the phase difference between the transmitter (TX) coil current and the receiver (RX) coil current without additional shielding coils or materials. A WPT system employing the proposed method adjusts the phase difference between the TX coil current and RX coil current by tuning a resonant capacitor of the RX coil. The conditions for minimizing the leakage magnetic field are derived, and the range of the resonant capacitor of RX, considering power transfer efficiency and the leakage magnetic field, is proposed. Through simulations and experiments, it is verified that the proposed method can reduce the leakage magnetic field level without any additional materials. For that reason, the proposed method can be suitable for size-limited, weight-limited or cost-limited WPT systems

Modeling, Verification, and Signal Integrity Analysis of High-Speed Signaling Channel with Tabbed Routing in High Performance Computing Server Board

It is necessary to reduce the crosstalk noise in high-speed signaling channels. In the channel routing area, the tabbed routing pattern is used to mitigate far-end crosstalk (FEXT), and the electrical length is controlled with a time domain reflectometer (TDR) and time domain transmission (TDT). However, unlike traditional channels having uniform width and space, the width and space of tabbed routing changes by segment, and the capacitance and inductance values of tabbed routing also change. In this paper, we propose a tabbed routing equivalent circuit modeling method using the segmentation approach. The proposed model was verified using 3D EM simulation and measurement results in the frequency domain. Based on the calculated inductance and capacitance parameters, we analyzed the insertion loss, FEXT, and self-impedance in the frequency domain, and TDT and FEXT in the time domain, by comparing the values of these metrics with and without tabbed routing. Using the proposed tabbed routing model, we analyzed tabbed routing with variations of design parameters based on self- and mutual-capacitance and inductance