scholarly journals Inductorless Frequency Synthesizers for Low-Cost Wireless

2021 ◽  
pp. 37-50
Author(s):  
Alessio Santiccioli
Keyword(s):  
Low Cost ◽  
Frequency Synthesizers ◽  
Design Guidelines ◽  
Reduction Technique ◽  
Ring Oscillator ◽  
Frequency Synthesis ◽  
Lc Oscillators ◽  
Low Jitter ◽  
Increasing Demand ◽  
Prior State

AbstractThe quest for ubiquitous wireless connectivity, drives an increasing demand for compact and efficient means of frequency generation. Conventional synthesizer options, however, generally trade one requirement for the other, achieving either excellent levels of efficiency by leveraging LC-oscillators, or a very compact area by relying on ring-oscillators. This chapter describes a recently introduced class of inductorless frequency synthesizers, based on the periodic realignment of a ring-oscillator, that have the potential to break this tradeoff. After analyzing their jitter-power product, the conditions that ensure optimum performance are derived and a novel digital-to-time converter range-reduction technique is introduced, to enable low-jitter and low-power fractional-N frequency synthesis. A prototype, which implements the proposed design guidelines and techniques, has been fabricated in 65 nm CMOS. It occupies a core area of 0:0275 mm$$^{2}$$ 2 and covers the 1:6-to-3:0 GHz range, achieving an absolute rms jitter (integrated from 30 kHz-to-30 MHz) of 397 fs at 2:5 mW power. With a corresponding jitter-power figure-of-merit of −244 dB in the fractional-N mode, the prototype outperforms prior state-of-the-art inductorless frequency synthesizers.

scholarly journals Synthesis, Structure and Diffusion Pathways of Fast Lithium-Ion Conductors in the Polymorphs α- and β-Li8SnP4

2021 ◽  
Author(s):  
Thomas F Fässler ◽  
Stefan Strangmüller ◽  
Henrik Eickkhoff ◽  
Wilhelm Klein ◽  
Gabriele Raudaschl-Sieber ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Lithium Ion ◽  
Conducting Materials ◽  
Increasing Demand ◽  
Battery Technology ◽  
Lithium Ion Conductors ◽  
And Diffusion ◽  
Ion Conductors

The increasing demand for a high-performance and low-cost battery technology promotes the search for Li+-conducting materials. Recently, phosphidotetrelates and aluminates were introduced as an innovative class of phosphide-based Li+-conducting materials...

Voice In Ear

2021 ◽  
Vol 5 (1) ◽  
pp. 1-25
Author(s):  
Yang Gao ◽  
Yincheng Jin ◽  
Jagmohan Chauhan ◽  
Seokmin Choi ◽  
Jiyang Li ◽  
...  
Keyword(s):  
User Authentication ◽  
Low Cost ◽  
The Body ◽  
Ear Canal ◽  
Replay Attacks ◽  
Increasing Demand ◽  
The Right ◽  
Sound Conduction ◽  
Enrollment Data ◽  
Secure Authentication

With the rapid growth of wearable computing and increasing demand for mobile authentication scenarios, voiceprint-based authentication has become one of the prevalent technologies and has already presented tremendous potentials to the public. However, it is vulnerable to voice spoofing attacks (e.g., replay attacks and synthetic voice attacks). To address this threat, we propose a new biometric authentication approach, named EarPrint, which aims to extend voiceprint and build a hidden and secure user authentication scheme on earphones. EarPrint builds on the speaking-induced body sound transmission from the throat to the ear canal, i.e., different users will have different body sound conduction patterns on both sides of ears. As the first exploratory study, extensive experiments on 23 subjects show the EarPrint is robust against ambient noises and body motions. EarPrint achieves an Equal Error Rate (EER) of 3.64% with 75 seconds enrollment data. We also evaluate the resilience of EarPrint against replay attacks. A major contribution of EarPrint is that it leverages two-level uniqueness, including the body sound conduction from the throat to the ear canal and the body asymmetry between the left and the right ears, taking advantage of earphones' paring form-factor. Compared with other mobile and wearable biometric modalities, EarPrint is a low-cost, accurate, and secure authentication solution for earphone users.

scholarly journals An Accurate DDS Method Using Compound Frequency Tuning Word and Its FPGA Implementation

Electronics ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 330 ◽  
Author(s):  
Yuqing Hou ◽  
Changlong Li ◽  
Sheng Tang
Keyword(s):  
Frequency Synthesizer ◽  
Frequency Tuning ◽  
Low Cost ◽  
Atomic Clock ◽  
Frequency Error ◽  
Frequency Synthesis ◽  
Direct Digital Synthesizer ◽  
Low Power Dissipation ◽  
Conversion Time ◽  
The Stability

Because of its high resolution, low cost, small volume, low power dissipation and less conversion time consumption, the direct digital synthesizer (DDS) method has been applied more and more in the fields of frequency synthesis and signal generation. However, only a limited number of precise frequency signals can be synthesized by the traditional DDS, for the reason that its accumulator modulus is fixed, and its frequency tuning word must be integer. In this paper, a precise DDS method using compound frequency tuning word is proposed, which improves the accuracy of synthesized signals at any frequency points on the premise of guaranteeing the stability of synthesized signals. In order to verify the effectiveness of the new method, a DDS frequency synthesizer based on FPGA is designed and implemented. Taking the rubidium atomic clock PRS10 as standard frequency source, the experiments shows that the frequency stability of the synthesized signal is better than 8.0 × 10−12/s, the relative frequency error is less than 4.8 × 10−12, and that the frequency accuracy is improved by three orders of magnitude compared with the traditional DDS method.

scholarly journals Co-Check: Collaborative Outsourced Data Auditing in Multicloud Environment

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Jian Mao ◽  
Wenqian Tian ◽  
Yan Zhang ◽  
Jian Cui ◽  
Hanjun Ma ◽  
...  
Keyword(s):  
Communication Networks ◽  
Resource Sharing ◽  
Cloud Storage ◽  
Low Cost ◽  
Data Outsourcing ◽  
Daily Lives ◽  
Outsourced Data ◽  
Low Performance ◽  
Increasing Demand ◽  
Data Auditing

With the increasing demand for ubiquitous connectivity, wireless technology has significantly improved our daily lives. Meanwhile, together with cloud-computing technology (e.g., cloud storage services and big data processing), new wireless networking technology becomes the foundation infrastructure of emerging communication networks. Particularly, cloud storage has been widely used in services, such as data outsourcing and resource sharing, among the heterogeneous wireless environments because of its convenience, low cost, and flexibility. However, users/clients lose the physical control of their data after outsourcing. Consequently, ensuring the integrity of the outsourced data becomes an important security requirement of cloud storage applications. In this paper, we present Co-Check, a collaborative multicloud data integrity audition scheme, which is based on BLS (Boneh-Lynn-Shacham) signature and homomorphic tags. According to the proposed scheme, clients can audit their outsourced data in a one-round challenge-response interaction with low performance overhead. Our scheme also supports dynamic data maintenance. The theoretical analysis and experiment results illustrate that our scheme is provably secure and efficient.

scholarly journals Total Ionizing Dose Effects on a Delay-Based Physical Unclonable Function Implemented in FPGAs

Electronics ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 163 ◽  
Author(s):  
Honorio Martin ◽  
Pedro Martin-Holgado ◽  
Yolanda Morilla ◽  
Luis Entrena ◽  
Enrique San-Millan
Keyword(s):  
Low Cost ◽  
Ring Oscillator ◽  
Radiation Environment ◽  
Key Generation ◽  
Total Ionizing Dose ◽  
Space Applications ◽  
Physical Unclonable Functions ◽  
Dose Effects ◽  
Total Ionizing Dose Effects

Physical Unclonable Functions (PUFs) are hardware security primitives that are increasingly being used for authentication and key generation in ICs and FPGAs. For space systems, they are a promising approach to meet the needs for secure communications at low cost. To this purpose, it is essential to determine if they are reliable in the space radiation environment. In this work we evaluate the Total Ionizing Dose effects on a delay-based PUF implemented in SRAM-FPGA, namely a Ring Oscillator PUF. Several major quality metrics have been used to analyze the evolution of the PUF response with the total ionizing dose. Experimental results demonstrate that total ionizing dose has a perceptible effect on the quality of the PUF response, but it could still be used for space applications by making some appropriate corrections.

scholarly journals Towards a Living Lab for Enhanced Thermal Comfort and Air Quality: Analyses of Standard Occupancy, Weather Extremes, and COVID-19 Pandemic

2021 ◽  
Vol 9 ◽  
Author(s):  
Giulia Ulpiani ◽  
Negin Nazarian ◽  
Fuyu Zhang ◽  
Christopher J. Pettit
Keyword(s):  
Environmental Quality ◽  
Low Cost ◽  
Design Guidelines ◽  
Weather Extremes ◽  
Fine Grained ◽  
Occupancy Patterns ◽  
Living Lab ◽  
Spatial Coverage ◽  
Educational Buildings ◽  
Extreme Variability

Maintaining indoor environmental (IEQ) quality is a key priority in educational buildings. However, most studies rely on outdoor measurements or evaluate limited spatial coverage and time periods that focus on standard occupancy and environmental conditions which makes it hard to establish causality and resilience limits. To address this, a fine-grained, low-cost, multi-parameter IOT sensor network was deployed to fully depict the spatial heterogeneity and temporal variability of environmental quality in an educational building in Sydney. The building was particularly selected as it represents a multi-use university facility that relies on passive ventilation strategies, and therefore suitable for establishing a living lab for integrating innovative IoT sensing technologies. IEQ analyses focused on 15 months of measurements, spanning standard occupancy of the building as well as the Black Summer bushfires in 2019, and the COVID-19 lockdown. The role of room characteristics, room use, season, weather extremes, and occupancy levels were disclosed via statistical analysis including mutual information analysis of linear and non-linear correlations and used to generate site-specific re-design guidelines. Overall, we found that 1) passive ventilation systems based on manual interventions are most likely associated with sub-optimum environmental quality and extreme variability linked to occupancy patterns, 2) normally closed environments tend to get very unhealthy under periods of extreme pollution and intermittent/protracted disuse, 3) the elevation and floor level in addition to room use were found to be significant conditional variables in determining heat and pollutants accumulation, presumably due to the synergy between local sources and vertical transport mechanisms. Most IEQ inefficiencies and health threats could be likely mitigated by implementing automated controls and smart logics to maintain adequate cross ventilation, prioritizing building airtightness improvement, and appropriate filtration techniques. This study supports the need for continuous and capillary monitoring of different occupied spaces in educational buildings to compensate for less perceivable threats, identify the room for improvement, and move towards healthy and future-proof learning environments.

scholarly journals Efficiency Evaluation for Femtocell Spectrum Access in LTE-Advanced

2015 ◽  
Vol 1 (1) ◽  
pp. 96-111
Author(s):  
Omar Arafat ◽  
Mark A Gregory
Keyword(s):  
Performance Analysis ◽  
Low Cost ◽  
Limited Area ◽  
Femtocell Networks ◽  
Indoor Coverage ◽  
Lte Advanced ◽  
Femtocell Network ◽  
Increasing Demand ◽  
Resource Allocation Scheme

Femtocells are considered one of the ultimate solutions for the ever increasing demand in LTE-Advance. Recently, wireless industries have resorted to femtocell networks in order to enhance indoor coverage and quality of service since macro-antennas fail to reach these objectives. In enabling indoor home or enterprise users with mobile broadband solutions, role of femtocells are crucially important. While considering low cost solutions for higher coverage and data rate, femtocells apparently have one of the best potentials for indoor users. Due to the dense self-deployment of femtocells in a limited area, serious inter-femtocell interference (IFI) may cause, which consequently results in severe performance degradation. To mitigate the IFI and utilize spectrum resource more efficiently, this paper proposes a cluster based femtocell deployments along with a capacity based cognitive resource allocation scheme .Three different channel configurations in a hybrid access femtocell network are considered for performance analysis. The results of a performance analysis of the cluster based femtocell configurations in a priority based users’ network are presented.

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