P2D-2 Quantitative Estimation of Ultrasonic Multiple Access Method Based on M-Sequence Code

Wang, Yong; Siginouchi, Takehiko; Hashimoto, Masahiko; Hachiya, Hiroyuki

doi:10.1109/ultsym.2007.396

Cited by 3 publications

(3 citation statements)

References 14 publications

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“…In our previous study of multiple ultrasonic sensing systems, asynchronous transmission using multiple M-sequence codes from each speaker was used to obtain highly precise measurements of TOF. 15,16) When the arrival times of ultrasonic signals from each speaker in the asynchronous multiple ultrasonic sensing system are nearly the same, all the multiple signals interfere with each other and the despread signal ZðtÞ can be represented by the conventional method as…”

Section: Processing Of Umammentioning

confidence: 99%

“…In our previous study of aerial ultrasonic sensing systems, we proposed and investigated an ultrasonic multiple access method (UMAM) and evaluated its effect in a case using four asynchronous systems. 15,16) Since the UMAM estimates replicas of undesired signals using known M-sequence codes of every ultrasonic sensing system, it can eliminate the negative effect of interference by subtracting the replicas from the received signals. From our experimental results, the UMAM was useful for highly precise measurements of round-trip TOF.…”

Section: Introductionmentioning

confidence: 99%

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Automatic Interference Elimination Algorithm for Ultrasonic Multiple Access Method

Wang

Suginouchi

Hashimoto

et al. 2008

jjap

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Ultrasonic sensing systems are currently used in automobiles and mobile robots. Recently, under conditions of multiple ultrasonic sensing systems operating in a small area, we proposed an ultrasonic multiple access method (UMAM) based on the spectrum-spread technology using M-sequence code. However, the effect of the UMAM depends on the preset threshold level. In this paper, we consider an automatic interference elimination algorithm for UMAM. Under conditions with a known interference-signal ratio, the normalized correlation function between two microphones can be used to investigate the effect of the threshold level in UMAM, and further, the optimal threshold level can be obtained from the maximum value of the normalized correlation function. Using a set of suitable training examples, the approximation function between the optimal threshold and the interference-signal ratio can be obtained. From the experimental results, the automatic interference elimination algorithm is a useful tool.

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Section: Processing Of Umammentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Automatic Interference Elimination Algorithm for Ultrasonic Multiple Access Method

Wang

Suginouchi

Hashimoto

et al. 2008

jjap

View full text Add to dashboard Cite

show abstract

“…If multiple outliers exist then the single outlier test is applied iteratively until all outliers have been removed (Kelly, 1998, Hewitson and Wang, 2006). The second method is to use robust methods that retain all observations but either down-weight suspect observations or minimise alternatives to the sum of the squared residuals (Wang and Wang, 2007).…”

Section: Introductionmentioning

confidence: 99%

A Comparison of Outlier Detection Procedures and Robust Estimation Methods in GPS Positioning

Knight

Wang

2009

J. Navigation

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With more satellite systems becoming available there is currently a need for Receiver Autonomous Integrity Monitoring (RAIM) to exclude multiple outliers. While the single outlier test can be applied iteratively, in the field of statistics robust methods are preferred when multiple outliers exist. This study compares the outlier test and numerous robust methods with simulated GPS measurements to identify which methods have the greatest ability to correctly exclude outliers. It was found that no method could correctly exclude outliers 100% of the time. However, for a single outlier the outlier test achieved the highest rates of correct exclusion followed by the MM-estimator and the L 1 -norm. As the number of outliers increased MM-estimators and the L 1 -norm obtained the highest rates of normal exclusion, which were up to ten percent higher than the outlier test. K E Y W O R D S 1. RAIM. 2. Outliers. 3. Robust. 4. Integrity.

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High-resolution acoustic imaging using multi-carrier waveforms synthesized by genetic algorithm

Ito

Sugimoto

Hashizume

2009

2009 IEEE International Ultrasonics Symposium

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P2D-2 Quantitative Estimation of Ultrasonic Multiple Access Method Based on M-Sequence Code

Cited by 3 publications

References 14 publications

Automatic Interference Elimination Algorithm for Ultrasonic Multiple Access Method

Automatic Interference Elimination Algorithm for Ultrasonic Multiple Access Method

A Comparison of Outlier Detection Procedures and Robust Estimation Methods in GPS Positioning

High-resolution acoustic imaging using multi-carrier waveforms synthesized by genetic algorithm

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