Improvement of Measurement Range via Chaotic Binary Frequency Shift Keying Excitation Sequences for Multichannel Ultrasonic Ranging System

Yao, Zhenjing; Li, Hong; Li, Yanan

doi:10.14257/ijca.2016.9.6.18

Cited by 6 publications

(4 citation statements)

References 16 publications

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“…It has the same advantages in multiple access and is easy to implement in ultrasonic systems. OOK [5,32], PSK [33,38], and FSK [39,40] are used to modulate and demodulate digital codes into analog signals.…”

Section: Existing Keying Code Division Multiple Accessmentioning

confidence: 99%

Improved Frequency Sweep Keying CDMA Using Faster R-CNN for Extended Ultrasonic Crosstalk Reduction

Park,

Baek

2023

Sensors

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Ultrasonic sensors are inexpensive and provide highly accurate measurements, even with simple hardware configurations, facilitating their use in various fields. When multiple ultrasonic sensors exist in the measurement space, crosstalk occurs due to other nodes, which leads to incorrect measurements. Crosstalk includes not only receiving homogeneous signals from other nodes, but also overlapping by other signals and interference by heterogeneous signals. This paper proposes using frequency sweep keying modulation to provide robustness against overlap and a faster region-based convolutional neural network (R-CNN) demodulator to reduce the interference caused by heterogeneous signals. The demodulator works by training Faster R-CNN with the spectrograms of various received signals and classifying the received signals using Faster R-CNN. Experiments implementing an ultrasonic crosstalk environment showed that, compared to on–off keying (OOK), phase-shift keying (PSK), and frequency-shift keying (FSK), the proposed method can implement CDMA even with shorter codes and is robust against overlap. Compared to correlation-based frequency sweep keying, the time-of-flight error was reduced by approximately 75%. While the existing demodulators did not consider heterogeneous signals, the proposed method ignored approximately 99% of the OOK and PSK signals and approximately 79% of the FSK signals. The proposed method performed better than the existing methods and is expected to be used in various applications.

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Section: Existing Keying Code Division Multiple Accessmentioning

confidence: 99%

Improved Frequency Sweep Keying CDMA Using Faster R-CNN for Extended Ultrasonic Crosstalk Reduction

Park,

Baek

2023

Sensors

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“…No interference between code "1" and code "0" occurs during signal overlap. Related studies include [34,35].…”

Section: Cdma-frequency Shift Keyingmentioning

confidence: 99%

Frequency Sweep Keying CDMA for Reducing Ultrasonic Crosstalk

Park

Baek

2022

Sensors

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Various sensors are embedded in automobiles to implement intelligent safety technologies such as autonomous driving and front–rear collision avoidance technology. In particular, ultrasonic sensors have been used in the past because they have an accuracy of centimeters to sub-centimeters in air despite their low cost and low hardware complexity. Recently, the crosstalk problem between ultrasonic sensors has been raised because the number of ultrasonic sensors in the unit space has increased as the number of vehicles increases. Various studies have been conducted to solve the crosstalk, but a demodulation error occurs when signals overlap. Therefore, in this paper, we propose a method that is robust to ultrasonic signal overlap, is robust even at shorter code length, and has reduced time of flight (TOF) error compared to the existing method by applying frequency sweep keying modulation based on code division multiple access (CDMA). As a result of the experiment, the code was detected accurately regardless of the overlap ratio of the two signals, and it was robust even in situations where the power of the two signals was different. In addition, it shows an accurate TOF estimation even if the ID code length is shorter than the existing on–off-keying, frequency shift keying, and phase shift keying methods.

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“…Since the self-interference can be mostly canceled by structural optimization, the crosstalk is generally more responsible for calculating wrong distances under low-speed conditions. Researchers have developed methods to eliminate crosstalk from different views, such as directivity [6][7][8], echo matching [9,10], and sequence design [11][12][13][14][15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

“…Typical excitation codes include pseudo-random codes, Barker codes, chaotic pulse position modulation codes, binary phase shift keying codes, quadrature phase shift keying codes, etc [12][13][14][15][16]. Among them, due to good sensitivity on initial conditions, aperiodic performance, capability to generate large amounts of excitation sequences with excellent autocorrelation, chaotic mapping has been widely applied and contributed significantly to crosstalk reduction [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Design of a fast echo matching algorithm to reduce crosstalk with Doppler shifts in ultrasonic ranging

Liu

Guo

2017

Meas. Sci. Technol.

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2017). Design of a fast echo matching algorithm to reduce crosstalk with Doppler shifts in ultrasonic ranging. Measurement Science and Technology, 28(2), [025103]. AbstractCrosstalk is a main factor for wrong distance measurement by ultrasonic sensors, and this problem becomes more difficult to deal with under Doppler effects. In this paper, crosstalk reduction with Doppler shifts on small platforms is focused on, and a fast echo matching algorithm (FEMA) is proposed on the basis of chaotic sequences and pulse coding technology, then verified through applying it to match practical echoes. Finally, we introduce how to select both better mapping methods for chaotic sequences, and algorithm parameters for higher achievable maximum of cross-correlation peaks. The results indicate the following: logistic mapping is preferred to generate good chaotic sequences, with high autocorrelation even when the length is very limited; FEMA can not only match echoes and calculate distance accurately with an error degree mostly below 5%, but also generates nearly the same calculation cost level for static or kinematic ranging, much lower than that by direct Doppler compensation (DDC) with the same frequency compensation step; The sensitivity to threshold value selection and performance of FEMA depend significantly on the achievable maximum of cross-correlation peaks, and a higher peak is preferred, which can be considered as a criterion for algorithm parameter optimization under practical conditions.

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Improvement of Measurement Range via Chaotic Binary Frequency Shift Keying Excitation Sequences for Multichannel Ultrasonic Ranging System

Cited by 6 publications

References 16 publications

Improved Frequency Sweep Keying CDMA Using Faster R-CNN for Extended Ultrasonic Crosstalk Reduction

Improved Frequency Sweep Keying CDMA Using Faster R-CNN for Extended Ultrasonic Crosstalk Reduction

Frequency Sweep Keying CDMA for Reducing Ultrasonic Crosstalk

Design of a fast echo matching algorithm to reduce crosstalk with Doppler shifts in ultrasonic ranging

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