@inproceedings {Simula.ND.213,
	title = {A Robust Model-Based Approach to Indoor Positioning Using Signal Strength},
	journal = {IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)},
	year = {2008},
	publisher = {IEEE},
	type = {Conference},
	abstract = {A simple technique to estimate the position of a mobile node inside a building is based on the Received Signal Strength (RSS). In previous publications, we investigated the effectiveness of using circular array antennas and beamforming in order to enable an access point to estimate the position of a mobile inside a building. We also discussed the feasibility of using model-based radio maps to reduce the need for extensive offline measurements. In this paper, a positioning algorithm based on the relative order of the received signal strengths is discussed. This algorithm in conjunction with the ray-tracing propagation model can have promising performance for indoor environments and essentially eliminates the needs for an extensive set of a priori measurement, training or intricate calibration.},
	isbn = {978-1-4244-2643-0},
	author = {Sayrafian-Pour, Kamran and Kaspar, Dominik},
	editor = {Friedel, Paul and Aghvami, Hamid and Dohler, Mischa and Sibille, Alain}
}
@inproceedings {Simula.ND.108,
	title = {A Novel Model-Based Indoor Positioning Using Signal Strength},
	journal = {18th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)},
	year = {2007},
	month = {September},
	pages = {1 - 5},
	publisher = {IEEE},
	type = {Conference},
	abstract = {A simple technique to estimate the position of a mobile node inside a building is based on the Received Signal Strength (RSS). In a previous publication, we investigated the feasibility of using circular array antennas and beamforming in order to enable an access point to estimate the position of a mobile inside a building. The approach utilized the two dimensional information (i.e. RSS for various azimuth directions) that is captured in a priori measured radio map. Generating these radio maps is not only extremely labor-intensive and time consuming but also sensitive to changes in the environment and possible source of interference. It would be interesting to find out if a deterministic propagation model such as ray tracing can be used to construct a radio map that effectively replaces the off-line manual measurements. In this paper, we investigate this issue and provide a novel positioning methodology that exhibits acceptable performance without the need for extensive set of measurements in the off-line mode. The performance for various parameters and building model accuracy will be presented and discussed.},
	isbn = {978-1-4244-1144-3},
	author = {Sayrafian-Pour, Kamran and Kaspar, Dominik},
	editor = {IEEE, }
}
@article {Simula.ND.109,
	title = {Application of Beamforming in Wireless Location Estimation},
	journal = {EURASIP Journal on Applied Signal Processing},
	volume = {2006},
	number = {2006},
	year = {2006},
	pages = {13},
	abstract = {A simple technique to estimate the position of a given mobile source inside a building is based on the received signal strength. For this methodology to have a reasonable accuracy, radio visibility of the mobile by at least three access points is required. To reduce the number of the required access points and therefore simplify the underlying coverage design problem, we propose a novel scheme that takes into account the distribution of RF energy around the receiver. In other words, we assume that the receiver is equipped with a circular array antenna with beamforming capability. In this way, the spatial spectrum of the received power can be measured by electronically rotating the main lobe around the 360-degree field of view. This spatial spectrum can be used by a single receiver as a means for estimating the position of the mobile transmitter. In this paper, we investigate the feasibility of this methodology, and show the improvement achieved in the positioning accuracy.},
	author = {Sayrafian-Pour, Kamran and Kaspar, Dominik}
}
@inproceedings {Simula.ND.107,
	title = {Source-Assisted Direction Estimation Inside Buildings},
	journal = {25th IEEE International Conference on Computer Communications (INFOCOM)},
	year = {2006},
	month = {April},
	pages = {1 - 8},
	publisher = {IEEE},
	type = {Conference},
	abstract = {Direction estimation inside buildings is a difficult and challenging task due to severe multipath signal propagation. Numerous algorithms and techniques exist that provide high resolution direction estimation under certain conditions and channel models; however, to our knowledge they all perform poorly at indoor environments. Here, we propose a technique that enables a receiver to achieve greater reliability in estimating source direction through some collaboration with the source. We assume that the receiver and the transmitter are synchronized and they are equipped with circular phased array antennas that have beamforming capability. If the transmitter-receiver pair always steer their main lobes into opposite directions, the spatial spectrum of the received power can be used as a mean for estimating the direction of the transmitting source. In this paper, we investigate the feasibility of this methodology, and show the achieved improvement.},
	isbn = {1-4244-0221-2},
	author = {Sayrafian-Pour, Kamran and Kaspar, Dominik},
	editor = {IEEE, }
}
@inproceedings {Simula.ND.106,
	title = {Indoor Positioning Using Spatial Power Spectrum},
	journal = {16th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)},
	year = {2005},
	pages = {2722 - 2726},
	publisher = {IEEE},
	type = {Conference},
	abstract = {A simple technique to estimate the position of a given mobile source inside a building is based on the received signal strength. For this methodology to have a reasonable accuracy, radio visibility of the mobile by at least three access points is required. To reduce the number of the required access points and therefore, simplify the underlying coverage design problem, we propose a new scheme that takes into account the distribution of RF energy around the receiver. In other words, we assume that the receiver is equipped with a circular antenna with beamforming capability. In this way, the spatial spectrum of the received power can be measured by rotating the antenna beam around the 360-degree field of view. This spatial spectrum can be used by a single receiver as a mean for estimating the position of a mobile transmitter. In this paper, we investigate the feasibility of this methodology, and show the improvement achieved in the positioning accuracy.},
	isbn = {9783800729098},
	author = {Sayrafian-Pour, Kamran and Kaspar, Dominik},
	editor = {IEEE, }
}
