Wifi Positioning Research Papers - Academia.edu (original) (raw)
Nowadays, Wireless Sensor Networks are becoming ubiquitous and increasingly attract investigators to focus on different aspects of them. In terms of localization estimation system, location algorithm play an important role to reach... more
Nowadays, Wireless Sensor Networks are
becoming ubiquitous and increasingly attract investigators to
focus on different aspects of them. In terms of localization
estimation system, location algorithm play an important role to
reach high accuracy. Many algorithms have been developed to
improve the accuracy of the system, but so far none has been able
to deliver complete satisfactory and reliable result. This paper
addresses a filter for smoothing the received signal strength
index (RSSI) based on Principle Component Analysis. To
enhance the accuracy of the system and overcome unwanted
signals, the proposed algorithm is utilized to reduce the noise for
triangulation localization approach instead of reducing the
database in fingerprint approach. Our algorithm divided each 10
received packets to a group and replaced a representative signal
for each group. A realistic demo system of the CC2430/CC2431
has been implemented in the fifth floor of Xi’an JiaotongLiverpool
University to represent the feasibility and accuracy of
our algorithm. The results show the enhancement in localization
accuracy in normal speed by at least 2 meters.
In this paper we present a distributed positioning system for indoor environments based on a network of compact independent anchor nodes operating as specialized WiFi access points. Each node is built with component-off-the-shelves and it... more
In this paper we present a distributed positioning
system for indoor environments based on a network of compact
independent anchor nodes operating as specialized WiFi access
points. Each node is built with component-off-the-shelves and it is
capable of standard IEEE 802.11 connectivity at 2.45GHz. The
enabling technology for the localization is the Switched Beam
Antenna (SBA) equipped in each node, which permits a space
division multiple access at network-level.
The positional information is the result of a maximum likeli-
hood estimation driven by the expected signal space partition of
the constellation, and it is tolerant to noisy power measurements,
such as Received Signal Strength Indicator, thanks to angular
filtering capability of the SBA, which in addition operates in
circular polarization.
Experimental validations demonstrate the performance of a
3-anchors network, operating within the IEEE 802.11 protocol,
monitoring a single nomadic node inside a 7m 2 indoor square
area. It results that 68% of the square area is covered with
a localization error below 50cm, with a mean error of 47cm.
Inside the triangular mesh defined by the three anchors, the
mean error drops to 39cm, with 88% of the area being below
50cm. In addition, the maximum error is always below 77cm.
Maybe you also hear many rumors about Wi-Fi and mobile phones harm for human health but in this article I'm going to clear the truth about this issue and then you will know to devices should you keep your distance with them to have a... more
Maybe you also hear many rumors about Wi-Fi and mobile phones harm for human health but in this article I'm going to clear the truth about this issue and then you will know to devices should you keep your distance with them to have a healthy life ahead. First of all we should know All of the devices that using wireless technology to communicate have a specific standard to operate that all of standards and have been analyzed and tested by global health and regulation organizations, and if any deceive not be able to fulfill required standards to pass quality controls which is based on very tight standards its won't certified as an standard device to present in shelves to sale. as you can see In below picture there are plenty of wireless devices that we are using in our daily life like mobile phones , microwaves ,radios ,hospital x-ray , etc … all of this devices use wireless technology to operate and communicate with other devices but all of them aren't in same level of harmfulness to human health. to understand this , all of these devices are separated and categorized in two main category IONIZING and NON-IONIZING the devices that are in ionizing category are completely harmful for human health like hospital X-ray that even we can't be in direct contact with , but the rest NON-IONIZING category devices like Wi-Fi devices are completely free of harm for human health .