Time‐of‐arrival estimation for smartphones based on built‐in microphone sensor

Liu, Zuoya; Chen, Ruizhi; Ye, Feng; Guo, Guangyi; Li, Zheng; Qian, Long

doi:10.1049/el.2020.2161

Cited by 3 publications

(3 citation statements)

References 6 publications

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“…This concept has a wide influence in the early western scholars' research on library evaluation, and also laid a theoretical foundation for future research on Libraries [ 4 ]. Liu, Z. and others pointed out that any type of service evaluation can be divided into three perspectives: effect evaluation, cost effect evaluation, and cost-benefit evaluation [ 5 ]. Among them, the effect evaluation is based on the satisfaction of the service object to its use needs.…”

Section: Literature Reviewmentioning

confidence: 99%

[Retracted] Analysis of the Influence of Library Information on the Utilization of Regional Environmental and Ecological Resources: From the Perspective of Intelligent Adaptive Learning

Jiang

Yang

2022

Journal of Environmental and Public Health

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In order to further develop and improve the management theory of public libraries, this paper studies the impact of library information on the utilization of regional environmental resources from the perspective of intelligent adaptive learning. Firstly, based on the data envelopment analysis method, this paper measures the efficiency of Public Libraries in various regions of China. Then, using Tobit model, this paper analyzes the environmental factors affecting the efficiency of public libraries from three aspects: financial allocation, per capita GDP, and per capita years of education. The results show that there is a significant correlation between per capita GDP, per capita years of education, and the efficiency of public libraries. There is a significant negative correlation between per capita GDP and public library efficiency (the coefficient is − 5.73 x 10 − 6 , and the probability of two-sided t -test is 0.0229); There is a significant positive correlation between the number of years of education per capita and the efficiency of Public Libraries (the coefficient is 0.0684, and the probability of two-sided t -test is 0.0169). Conclusion: This study provides a reference for the performance evaluation of provincial public libraries.

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Section: Literature Reviewmentioning

confidence: 99%

[Retracted] Analysis of the Influence of Library Information on the Utilization of Regional Environmental and Ecological Resources: From the Perspective of Intelligent Adaptive Learning

Jiang

Yang

2022

Journal of Environmental and Public Health

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“…At the same time, the TDOA fingerprint positioning method requires collecting fingerprint information in advance, which is time-consuming and laborious. In the article [40], laser signals are utilized to approximately synchronize the acoustic base station with the mobile phone. However, the laser signal is affected by sight distance conditions, and the practical application of this system is not reliable.…”

Section: Introductionmentioning

confidence: 99%

Acoustic TDOA Measurement and Accurate Indoor Positioning for Smartphone

Cheng

2023

Future Internet

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The global satellite navigation signal works well in open areas outdoors. However, due to its weakness, it is challenging to position continuously and reliably indoors. In this paper, we developed a hybrid system that combines radio signals and acoustic signals to achieve decimeter-level positioning indoors. Specifically, acoustic transmitters are synchronized with different codes. At the same time, our decoding scheme only requires a simple cross-correlation operation without time-frequency analysis. Secondly, acoustic signals will be reflected by glass, walls and other obstacles in the indoor environment. Time difference of arrival (TDOA) measurement accuracy is seriously affected. We developed a robust first path detection algorithm to obtain reliable TDOA measurement values. Finally, we combine the maximum likelihood (ML) algorithm with the proposed TDOA measurement method to obtain the location of the smartphone. We carried out static positioning experiments for smartphones in two scenes. The experimental results show that the average positioning error of the system is less than 0.5 m. Our system has the following advantages: (1) smartphone access. (2) an unlimited number of users. (3) easily deployed acoustic nodes. (4) decimeter-level positioning accuracy.

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“…In the livestock sector MEMS acoustic transducers have been used to estimate the state of health of animals [5] while in industrial fields they have been used for noise and vibration measurements [6], as resonant photoacoustic combustion gas monitors [7] or as hydrophones for pipeline leak detection [8]. In recent years MEMS acoustic sensors and actuators have been extensively produced for consumer applications as microphones for wearable devices [9,10] and voice controllable systems [11,12] or as microspeakers for in-ear devices [13,14]. MEMS acoustic transducers rely on the conversion of energy between mechanical/acoustic and electrical domains which can be achieved by different transduction mechanisms.…”

Section: Introductionmentioning

confidence: 99%

Piezoelectric MEMS Acoustic Transducer with Electrically-Tunable Resonant Frequency

et al. 2022

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The paper presents a technique to obtain an electrically-tunable matching between the series and parallel resonant frequencies of a piezoelectric MEMS acoustic transducer to increase the effectiveness of acoustic emission/detection in voltage-mode driving and sensing. The piezoelectric MEMS transducer has been fabricated using the PiezoMUMPs technology, and it operates in a plate flexural mode exploiting a 6 × 6 mm doped silicon diaphragm with an aluminum nitride (AlN) piezoelectric layer deposited on top. The piezoelectric layer can be actuated by means of electrodes placed at the edges of the diaphragm above the AlN film. By applying an adjustable bias voltage Vb between two properly-connected electrodes and the doped silicon, the d31 mode in the AlN film has been exploited to electrically induce a planar static compressive or tensile stress in the diaphragm, depending on the sign of Vb, thus shifting its resonant frequency. The working principle has been first validated through an eigenfrequency analysis with an electrically induced prestress by means of 3D finite element modelling in COMSOL Multiphysics®. The first flexural mode of the unstressed diaphragm results at around 5.1 kHz. Then, the piezoelectric MEMS transducer has been experimentally tested in both receiver and transmitter modes. Experimental results have shown that the resonance can be electrically tuned in the range Vb = ±8 V with estimated tuning sensitivities of 8.7 ± 0.5 Hz/V and 7.8 ± 0.9 Hz/V in transmitter and receiver modes, respectively. A matching of the series and parallel resonant frequencies has been experimentally demonstrated in voltage-mode driving and sensing by applying Vb = 0 in transmission and Vb = −1.9 V in receiving, respectively, thereby obtaining the optimal acoustic emission and detection effectiveness at the same operating frequency.

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Time‐of‐arrival estimation for smartphones based on built‐in microphone sensor

Cited by 3 publications

References 6 publications

[Retracted] Analysis of the Influence of Library Information on the Utilization of Regional Environmental and Ecological Resources: From the Perspective of Intelligent Adaptive Learning

[Retracted] Analysis of the Influence of Library Information on the Utilization of Regional Environmental and Ecological Resources: From the Perspective of Intelligent Adaptive Learning

Acoustic TDOA Measurement and Accurate Indoor Positioning for Smartphone

Piezoelectric MEMS Acoustic Transducer with Electrically-Tunable Resonant Frequency

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