Chirp-rate quasi-orthogonality based DSSS-CDMA system for underwater acoustic channel

Yuan, Fei; Jia, Zhenyu; Cheng, En

doi:10.1016/j.apacoust.2019.107163

Cited by 9 publications

(5 citation statements)

References 12 publications

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“…

is defined as:

where

[ 51 ]. As for the Chirp identification, the optimal α is defined as

, and

is the sampling rate of the system.…”

Section: Framework Of the Systemmentioning

confidence: 99%

Smartphone-Based Social Distance Detection Technology with Near-Ultrasonic Signal

Jia

Shu

Wang

et al. 2022

Sensors

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With the emergence of COVID-19, social distancing detection is a crucial technique for epidemic prevention and control. However, the current mainstream detection technology cannot obtain accurate social distance in real-time. To address this problem, this paper presents a first study on smartphone-based social distance detection technology based on near-ultrasonic signals. Firstly, according to auditory characteristics of the human ear and smartphone frequency response characteristics, a group of 18 kHz–23 kHz inaudible Chirp signals accompanied with single frequency signals are designed to complete ranging and ID identification in a short time. Secondly, an improved mutual ranging algorithm is proposed by combining the cubic spline interpolation and a two-stage search to obtain robust mutual ranging performance against multipath and NLoS affect. Thirdly, a hybrid channel access protocol is proposed consisting of Chirp BOK, FDMA, and CSMA/CA to increase the number of concurrencies and reduce the probability of collision. The results show that in our ranging algorithm, 95% of the mutual ranging error within 5 m is less than 10 cm and gets the best performance compared to the other traditional methods in both LoS and NLoS. The protocol can efficiently utilize the limited near-ultrasonic channel resources and achieve a high refresh rate ranging under the premise of reducing the collision probability. Our study can realize high-precision, high-refresh-rate social distance detection on smartphones and has significant application value during an epidemic.

show abstract

“…

is defined as:

where

[ 51 ]. As for the Chirp identification, the optimal α is defined as

, and

is the sampling rate of the system.…”

Section: Framework Of the Systemmentioning

confidence: 99%

Smartphone-Based Social Distance Detection Technology with Near-Ultrasonic Signal

Jia

Shu

Wang

et al. 2022

Sensors

View full text Add to dashboard Cite

show abstract

“…The acquired, relative distances to these beacons can be used in multilateration or other geometric models to find the position of the mobile nodes [14]. Identification of the sound signal is crucial here, and multiple access techniques (e.g., FDMA, TDMA, CDMA) as proposed by [15][16][17] can achieve this. These scheme are outside the scope of this paper which focuses on the proposed ranging system in reverberant and noisy environments.…”

Section: Hybrid Rf-ultrasonic Systemmentioning

confidence: 99%

High precision hybrid RF and ultrasonic chirp-based ranging for low-power IoT nodes

Cox

Perre

Wielandt

et al. 2020

J Wireless Com Network

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Hybrid acoustic-RF systems offer excellent ranging accuracy, yet they typically come at a power consumption that is too high to meet the energy constraints of mobile IoT nodes. We combine pulse compression and synchronized wake-ups to achieve a ranging solution that limits the active time of the nodes to 1 ms. Hence, an ultra low-power consumption of 9.015 µW for a single measurement is achieved. The operation time is estimated on 8.5 years on a CR2032 coin cell battery at a 1 Hz update rate, which is over 250 times larger than state-of-the-art RF-based positioning systems. Measurements based on a proof-of-concept hardware platform show median distance error values below 10 cm. Both simulations and measurements demonstrate that the accuracy is reduced at low signal-to-noise ratios and when reflections occur. We introduce three methods that enhance the distance measurements at a low extra processing power cost. Hence, we validate in realistic environments that the centimeter accuracy can be obtained within the energy budget of mobile devices and IoT nodes. The proposed hybrid signal ranging system can be extended to perform accurate, low-power indoor positioning.

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“…Assisted GPS utilizes an earthbound cellular network to upgrade GPS receiver performance [26]. A GPS contains three parts; a location server, mobile station, and wireless communication connection.…”

Section: F Assisted-gps For Narrowband Cdmamentioning

confidence: 99%

Network Aided Positioning Techniques Based on Rssi and Signal Processing

Kevin¹

2020

ijarcs

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The researcher's attentiveness has been diverted to create mobile positioning techniques based on RSSI and with signal processing techniques like GPS and multidimensional scaling. The localization system has been proposed in different topologies with a lot of tactical challenges in mobile positioning. Several positioning systems has been proposed for mobile based wireless sensor network and some are in a dense environment. In consequence, it is not practical to use a same localization system for different types of networks. Therefore, a system and algorithm are required which can calibrate itself and transform the global coordinates according to the environmental changes. In this article we provide an overview of different localization systems and provide some insight overview for future researchers.

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Chirp-rate quasi-orthogonality based DSSS-CDMA system for underwater acoustic channel

Cited by 9 publications

References 12 publications

Smartphone-Based Social Distance Detection Technology with Near-Ultrasonic Signal

Smartphone-Based Social Distance Detection Technology with Near-Ultrasonic Signal

High precision hybrid RF and ultrasonic chirp-based ranging for low-power IoT nodes

Network Aided Positioning Techniques Based on Rssi and Signal Processing

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