Abstract-In recent years, location determination systems have gained a high importance due to their rule in the context aware systems. In this paper, we will design a multi-floor indoor positioning system based on Bayesian Graphical Models (BGM). Graphical models have a great flexibility on visualizing the relationships between random variables. Rather than using one sampling technique, we are going to use multiple sets each set contains a collection of sampling techniques, the accuracy of each set will be compared with each other.

This paper presents a reconfigurable multiple element microstrip rectangular linear array antenna integrated with radio frequency (RF) switches. The corporate feed design concept is used to excite the linear array antenna that consists of 8 elements of rectangular patches at 5.8 GHz. Two PIN diode switches were deployed at the feeding line to activate the two arrays of patches that are located on the left and right sides of the antenna structure. The behavior of the reconfigurable multiple element linear antenna array system has been investigated with respect to the beam shaping characteristic. The comparisons of the performance between two structures, with and without Wilkinson Power Divider (WPD) are discussed in this paper. Two different beam patterns were achieved through the reconfigurable antenna at different number of elements design that incorporates with PIN diode switches and modified WPD concept. The simulation and the measurement results for 4 and 8 elements array antenna structure are presented.

Abstract-A new antenna structure is formed by combining the concept of reconfigurable planar antenna array (RPAA) with the parasitic elements to produce beam steering patterns. The antenna has been integrated with the PIN diode switches that enable the beam to be steered in the desired direction. This has been done by changing the switch state to either on or off mode. In this work, a number of parasitic elements have been applied to the antenna, namely reflectors and directors. They are placed in between the driven elements, which is aimed to improve the beam steering angle. With such configuration, the main beam radiated by the array can be tilted due to the effect of mutual coupling between the driven elements and parasitic elements (reflectors and director). The unique property of this antenna design is that instead of fabricating all together in the same plane, the antenna's feeding network is separated from the antenna radiating elements (the patches) by an air gap distance. This allows reducing the spurious effects from the feeding line. The optimization results for the resonant frequencies of the antennas with variable air gap heights are also been studied. The antenna is made for 5.8 GHz. Good agreement is achieved between the simulation and measurement.

A new antenna structure with lower side lobe pattern and higher gain was designed by combining a microstrip rectangular planar antenna array with the separated feed network technique. In this paper, the side lobe behaviors of two different radiating structures have been studied and compared. The first antenna configuration ("Structure 1") is a 16-element planar antenna array whose feed line is printed on the same plane as the radiating elements. The second one ("Structure 2") is a 16-element planar antenna array whose feed network is separated from the radiating elements by an air gap. This technique enables one to reduce the unwanted spurious effects from the feed line. Both antennas are designed at 5.8 GHz. Compared to "Structure 1" we show that the optimization of "Structure 2" allows reducing the side lobe level and increasing the antenna gain. The experimental results are shown to be in very good agreement with the numerical simulations.

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