Near field electromagnetic ranging and localization

Abstract

<P>THE RESEARCH INTEREST OF THIS THESIS IS IN THE CHANNEL MODELING FOR ULTRA-WIDEBAND (UWB) AND THE APPLICATION OF NEAR FIELD ELECTROMAGNETIC RANGING (NFER) FOR LOCALIZATION. AN UWB CHANNEL MODEL FOR INDOOR AND OUTDOOR OFFICE ENVIRONMENT IS DEVELOPED FROM EXTENSIVE CHANNEL MEASUREMENTS. THE CHANNEL MODEL FOLLOWS THE SALEH-VALENZUELA (S-V) MODEL, WITH MODIFICATIONS ON THE RAY ARRIVAL TIMES AND AMPLITUDE STATISTICS TO FIT THE EMPIRICAL DATA. AS FOR NFER, THE CRAMER-RAO BOUNDS (CRBS) FOR NFER UNDER AWGN AND INDOOR CONDITIONS ARE DERIVED HERE. IT IS OBSERVED THAT NFER ACCURACY IS DEPENDENT ON THE TRUE RANGE AND FREQUENCY USED, BESIDES THE SIGNAL-NOISE RATIO. HENCE, FREQUENCY SELECTION SCHEMES ARE DEVISED FOR THE USE OF SINGLE AND MULTIPLE FREQUENCIES. USING THESE SCHEMES, THE MOST APPROPRIATE SET OF FREQUENCIES CAN BE SELECTED FOR OPTIMAL RANGING PERFORMANCE OVER WIDE RANGES. A MODIFIED MAXIMUM LIKELIHOOD ESTIMATION (MLE) ALGORITHM FOR USE WITH MULTIPLE FREQUENCIES IN NFER HAS BEEN DEVELOP