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Device Power Saving with Time-Frequency Adaptation: Joint BWP-DRX Design with BWP Switching Delay Considered

IEEE Transactions on Mobile Computing 2025年第7期24卷 6613-6627页

作者： Tsai, Cheng-Wei Lin, Kuang-Hsun Wei, and Hung-Yu National Taiwan University Graduate Institute of Communication Engineering 106319 Taiwan National Taiwan University Graduate Institute of Communication Engineering Department of Electrical Engineering 106319 Taiwan

In today's ever-growing data traffic landscape, optimizing network power efficiency and performance has become crucial. Discontinuous Reception (DRX) and Bandwidth Parts (BWP) are two key technologies that fulfill this pursuit. DRX is a time-domain power-saving technology that allows user equipment (UE) to switch off their radio frequency module. BWP switching is a frequency domain operation that allows UE to operate on only partial bandwidth for power saving. Investigating the interaction and trade-off between DRX and BWP is a must to optimize network efficiency and enhance network performance. This work proposed a novel BWP-DRX joint mechanism and its analytical model that leverages the concept of "Detect time" with the consideration of BWP switching delay. The model reduces packet loss rate by 50%, packet delay by 36% and increases the energy efficiency rate by 50% when arrival rate is high with the trade-off of 12% power efficiency reduction when arrival rate is low compared to the model without Detect time. The influence of each parameter is further analyzed to reach the best network efficiency under different traffic conditions. © 2025 IEEE. All rights reserved.

关键词： Bandwidth

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A 0.9-V 36% PAE Broadband Continuous Class-F CMOS mm-Wave Power Amplifier Using Novel Current-Mode Power Combiner

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IEEE Transactions on Microwave Theory and Techniques 2025年第2期73卷 938-952页

作者： Batabyal, Anik Zele, Rajesh H. Khyalia, Santosh Kumar Wang, Huei Department of Electrical Engineering Mumbai400076 India Graduate Institute of Communication Engineering National Taiwan University Taipei10617 Taiwan National Taiwan University Department of Electrical Engineering The Graduate Institute of Communication Engineering Taipei10617 Taiwan

This article presents a fully integrated broadband two-stage differential millimeter-wave (mm-Wave) power amplifier (PA) based on a novel current-mode power combiner. New harmonic terminations have been proposed to obtain an increase in power-added efficiency (PAE) over a wide range of frequencies. A capacitive third harmonic termination to the drain impedance at the output stage of PA provides flexibility in choosing a lower self-resonance frequency (SRF) of the transformer in the output matching network. The freedom of choosing a lower SRF enables the utilization of lateral coupling in the transformer (output matching network), which further removes the requirement of ultrathick top metal (UTM) layer. A low-cost solution has been developed and the PA shows improved performance even without UTM. The proposed idea generalizes the load impedance terminations and reduces the technology dependence of PA design. The PA operates both in the Ka-band and the fifth-generation (5G)-FR2 band. The PA fabricated in a 40-nm CMOS process without a UTM layer occupies a core area of 0.31 mm2. The proposed PA achieves 19.1 dB of measured small-signal gain at 28 GHz, a peak power output of 15.9 dBm from 28 to 31 GHz with a peak power-added efficiency (PAE) of 36% from a supply voltage of 0.9 V. The -3-dB bandwidth of 28.3% achieved by this design is one of the highest reported bandwidths for CMOS mm-Wave PAs. For 64-quadrature amplitude modulation (QAM) 5G-new radio (5G-NR) signal input with 200-MHz bandwidth, the PA shows a measured error vector magnitude (EVM) of -27 dB at 28 GHz and the adjacent channel leakage ratio (ACLR) ≈ -32 dBc without utilizing digital predistortion (DPD). © 1963-2012 IEEE.

关键词： Quadrature amplitude modulation

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Mobility-Enabled Dynamic Grouping for Multicast Broadcast Service

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IEEE Transactions on Broadcasting 2024年第4期70卷 1167-1180页

作者： Lin, Kuang-Hsun Chen, Ting-Wei Wei, Hung-Yu National Taiwan University Graduate Institute of Communication Engineering Taipei106319 Taiwan National Taiwan University Graduate Institute of Communication Engineering The Department of Electrical Engineering Taipei106319 Taiwan

3GPP has established the Multicast Broadcast Services (MBS) standard to accommodate the escalating bandwidth demands of emerging applications like mixed reality and online gaming. MBS offers an efficient means of simultaneously delivering content to different users through the same wireless resources. However, the efficacy of grouping is intricately linked to user mobility and the channel quality of the weakest link. Notably, it is identified that handovers can cause significant interruptions in MBS transmissions. To address this, our paper introduces a novel dynamic grouping scheme capable of adapting to user mobility. Our results demonstrate superior performance compared to state-of-the-art methods without introducing much signaling overhead associated with MBS group management. © 1963-2012 IEEE.

关键词： Multicasting

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A 2.4-GHz CMOS Efficiency-Enhanced Rectifier With a Differential-Feed Patch Antenna

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IEEE Microwave and Wireless Technology Letters 2024年第2期34卷 229-232页

作者： Huang, Zhi-Yong Chen, Yi-Jan Emery Graduate Institute of Electronics Engineering the Graduate Institute of Communication Engineering the Department of Electrical Engineering National Taiwan University Taipei10617 Taiwan

This letter presents the codesign of a 2.4-GHz CMOS rectifier and an antenna for efficiency enhancement at low input power. The RF differential-driven rectifier architecture is used to lower the driving voltage required to turn on the transistors. The high-resistance feedback path with an offset voltage is added to the rectifier circuit to reduce the reverse leakage current for efficiency enhancement. The rectifier is connected directly to the differential-feed antenna to eliminate the need and loss of a balun. The measured power conversion efficiency (PCE) of the rectifier achieves 63% at the input power of −8 dBm. © 2024 institute of Electrical and Electronics Engineers Inc.. All rights reserved.

关键词： Wireless sensor networks

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Accuracy enhancement of Wi-Fi positioning by ranging in dense UWB networks

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computer communications 2024年 213卷 179-187页

作者： Li, Chao-Hsiang Lai, Alexander I-Chi Wu, Ruey-Beei Graduate Institute of Communication Engineering and the Department of Electrical Engineering National Taiwan University Taipei10617 Taiwan

This study proposed a fusion-based approach of Wi-Fi fingerprint positioning with relatively accurate UWB ranging in dense wireless networks (DWNs) to optimize indoor localization accuracy. Such an optimization was achieved through a proposed objective or "loss" function that minimizes the total positioning errors of the nodes composing a virtual geometric structure with the internode distances preserved during optimization in the DWN. Theoretical analysis and simulation results of DWNs up to 100 nodes revealed that, with at least 6 extra measured distances among as few as 4 participating nodes including the device-under-targeting (DUT) itself, the resulting localization accuracy improvement was proportional to the square root of the number of participating nodes towards the limit of the ranging error. Per experiment outcomes of a 10-node UWB DWN, our Wi-Fi/UWB ensemble reduced the baseline Wi-Fi K-nearest neighbors (KNN) fingerprint localization error by up to 69.8 %, further validating our theoretical and simulation results. © 2023 Elsevier B.V.

关键词： Wi-Fi

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A Novel Compact Dual-Functional Circuit With Differential-Mode Equalization and Broadband Common-Mode Suppression Using Patterned Ground Plane

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IEEE Transactions on Components, Packaging and Manufacturing Technology 2024年第2期14卷 300-308页

作者： Chen, Yu-Ren Lin, Yi-Ting Wu, Tzong-Lin Graduate Institute of Communication Engineering National Taiwan University Department of Electrical Engineering Taipei10617 Taiwan

A new passive differential-mode equalizer (DME) equipped with the function of common-mode (CM) suppression is proposed by using differential shunt stubs (DSSs) and patterned ground structure (PGS). The DSS is mainly responsible for generating the high-pass response in differential mode to achieve the equalization effect with a data rate of up to 10 Gbps, while the PGS is responsible for creating the wideband CM suppression from 2 GHz to more than 10 GHz. The equivalent circuit model is constructed and the frequency-domain analysis is applied to calculate the even-mode and odd-mode responses. The calculated responses are validated and then used to solve the approximated resonant frequencies and cut-off frequency of the CM response analytically. Additionally, time-domain eye simulation, full-wave simulation, and measurement are performed to verify the effectiveness of differential-mode equalization and wideband CM suppression. Most crucially, this proposed circuit not only provides better performance on signal integrity, but also features the most compact size in a 2-layer printed circuit board (PCB) and the lowest frequency 2.1 GHz of the CM stopband, in contrast to the previous works. © 2011-2012 IEEE.

关键词： Equivalent circuits

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VoWi-Fi security threats: Address resolution protocol attack and countermeasures

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IET Networks 2024年第2期13卷 129-146页

作者： Lu, Kuan-Chu Liu, I.-Hsien Chang, Keng-Hao Li, Jung-Shian Department of Electrical Engineering Institute of Computer and Communication Engineering National Cheng Kung University Tainan Taiwan

B5G/6G networks are facing challenges in the deployment of additional base stations. However, Taiwan's four major operators have launched VoWi-Fi calling services to maintain signal quality and coverage for customers. These services pose potential threats when users connect to untrusted Wi-Fi networks. Therefore, the authors utilised commercial equipment to study the security of VoWi-Fi calling services offered by Taiwan's four major telecom companies. The authors employed address resolution protocol attack methods to develop two verification attacks that bypass existing security measures: one for dropping session initiation protocol packets and the other for dropping voice call packets, both capable of circumventing current security defences. Through real-world experiments, the authors confirmed their feasibility and assessed their potential harm. Consequently, two defence methods are proposed. The first is an anti-attack algorithm for app and device manufacturers to detect the security of the user's calling environment. The second is a recommendation for telecom operators to implement new detection mechanisms to safeguard user rights. The cover image is based on the Case Study VoWi-Fi security threats: Address resolution protocol attack and countermeasures by Kuan-Chu Lu et al., https://***/10.1049/ntw2.12113. © 2024 The Authors. IET Networks published by John Wiley & Sons Ltd on behalf of The Institution of engineering and Technology.

关键词： Wi-Fi

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Common criteria for security evaluation and malicious intrusion detection mechanism of dam supervisory control and data acquisition system

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IET Networks 2024年第5-6期13卷 546-559页

作者： Lu, Kuan-Chu Liu, I-Hsien Liu, Zong-Chao Li, Jung-Shian Department of Electrical Engineering Institute of Computer and Communication Engineering National Cheng Kung University Tainan Taiwan

Supervisory control and data acquisition (SCADA) systems are vital in monitoring and controlling industrial processes through the web. However, while such systems result in lower costs, greater utilisation efficiency, and improved reliability, they are vulnerable to cyberattacks, with consequences ranging from the inconvenience and minor disruption to severe physical damage and even loss of life. The authors evaluate the security of the Dam system in the form of Common Criteria, develop safety goals to improve this safety, and focus on threats and risks to the dam SCADA system. Finally proposes an anomaly-based machine-learning framework for detecting malicious network attacks in the SCADA system of a dam. Three unsupervised classification algorithms are considered: hierarchical clustering, local outlier factor, and isolation forest. It is shown that the hierarchical clustering algorithm achieves the highest precision and F-score of the three algorithms. Overall, the results confirm the effectiveness of anomaly-based detection algorithms in enhancing the robustness of SCADA systems toward malicious attacks. At the same time, it complies with the security objectives of Common Criteria, achieving the safety and protection of the dam. © 2024 The Author(s). IET Networks published by John Wiley & Sons Ltd on behalf of The Institution of engineering and Technology.

关键词： Internet of things

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A novel Cosine-Cosine chaotic map-based video encryption scheme

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Journal of engineering and Applied Science 2024年第1期71卷 36页

作者： Kumari, Sweta Dua, Mohit Dua, Shelza Dhingra, Deepti Department of Computer Engineering National Institute of Technology Kurukshetra India Department of Electronics and Communication Engineering National Institute of Technology Kurukshetra India

The surge in online activities has led to the increasing popularity of sharing video data across diverse applications, including online education tutorials, social networking, video calling, and OTT platforms. Encryption prevents unauthorized access to the transmitted data over unreliable channels. The well-known features of chaos theory such as random behaviour, unpredictability, and initial parameters dependency facilitate its use in cryptography. Many security issues are faced by chaos-based cryptosystems because of their less complexity. Hence, a new Cosine-Cosine chaotic map characterized by intricate chaotic behaviour is designed in the current study. Additionally, we formulate an original video encryption scheme employing this Cosine-Cosine chaotic map. The encryption process involves five steps, beginning with the segmentation of the original video into frames based on its frame rate. In the second phase, a 384 bits pseudorandom key is generated that is further divided into three subkeys of 128 bits each. The novel Cosine-Cosine chaotic map-based sequence is generated. In the fourth step, red, green, and blue components are encrypted using the pseudorandom key and the chaotic sequence. In the last step, we combine encrypted frames to get cipher video. The security analysis validates that the proposed encryption protects against eavesdropping. © The Author(s) 2024.

关键词： Cryptography

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A Lightweight Broadband Circularly Polarized Stacked Patch Antenna Formed by Meshed Aluminum Disks for Inter-Satellite communication

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IEEE Antennas and Wireless Propagation Letters 2024年第4期23卷 1326-1330页

作者： Liao, Hsiu-Ping Tsai, Yun-Ting Chen, Shih-Yuan National Taiwan University Department of Electrical Engineering Graduate Institute of Communication Engineering Taipei10617 Taiwan

A broadband lightweight circularly polarized (CP) stacked patch antenna is proposed for use in the 1.8-2.3 GHz LEO-to-GEO inter-satellite links. It consists of four meshed aluminum disks supported by polyamide spacers. No dielectric substrate is used in the design to avoid heat storage in the substrate and reduce antenna weight. Thanks to the meshed structure, the antenna weight is reduced by half and is only 30 g. The broadband CP radiation is achieved via the sequential rotation feeding structure and the stacked patch topology. For verification, a prototype antenna is built and tested. In addition to the agreement between the simulated and measured results, the prototype antenna exhibits an overlapped 10 dB return loss and 3 dB axial ratio bandwidth of 33.81% and in-band realized gain of 8.4-9.3 dBic at broadside, meeting the requirements of the intended inter-satellite link application. © 2002-2011 IEEE.

关键词： Substrates

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