Zafer Sahinoglu

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UWB technology provides an excellent means for wireless positioning due to its high resolution capability in the time domain. Its ability to resolve multipath components makes it possible to obtain accurate location estimates without the need for complex estimation algorithms. In this article, theoretical limits for TOA estimation and TOA-based location(More)
Wireless sensor networks are emerging as an important area for communications. They enable a wealth of new applications including surveillance, building control, factory automation, and invehicle sensing. The sensor nodes have to operate under severe constraints on energy consumption and form factor, and provide the ability for precise self-location of the(More)
Ranging with energy detectors enables low-cost implementation. However, any interference can be quite detrimental to range accuracy. We develop a method that performs nonlinear filtering on the received signal energy to mitigate multiuser interference (MUI); and we test it over time-hopping and direct sequence impulse radio ultrawideband signals.(More)
In this paper, performances of stored-reference, transmitted-reference (TR), and energy-detection (ED)-based time-of-arrival estimation techniques are analyzed for impulse-radio ultra-wideband (IR-UWB) systems at sub-Nyquist sampling rates. First, an additive white Gaussian noise channel is considered to emphasize certain fundamental issues related to these(More)
The high time resolution of ultra-wideband (UWB) signals enables wireless devices to perform accurate range estimation. In order to realize UWB systems with accurate ranging capabilities, both theoretical limits on range estimation and practical algorithms that approach those limits should be investigated. This paper provides a survey of various UWB ranging(More)
In this letter, a threshold selection technique for time of arrival estimation of ultra-wideband signals is proposed. It exploits the Kurtosis of the received signal samples. The dependency between the Kurtosis and optimal normalized threshold are investigated via simulations. The proposed technique yields efficient threshold selections, has low complexity(More)
In short range communications, the use of RSS measurements in conjunction with TOA or TDOA leads to enhanced estimation accuracy with respect to the case where only TOA or TDOA are used. In this article, we derive the Cramer-Rao Bound (CRB) for location estimation accuracy of two different hybrid schemes: TOA/RSS and TDOA/RSS. For short ranges, the hybrid(More)