1. An Exponential-Rayleigh Model for RSS-based Device-Free Localization
and Tracking
Abstract:
A common technical difficulty in device-free target localization and
tracking with a wireless sensor network is that the change of the received
signal strength (RSS) of the link often becomes more unpredictable due to
the multipath interferences and lead to unsatisfactory or even unstable
localization and tracking performance. This work focuses on developing a
new RSS-based model, called Exponential-Rayleigh (ER) model, which can
alleviate the unpredictable problem and offer superior tracking
performance in both outdoor and indoor environment. Based on data from
extensive experiments, we first derive the ER model of the received signal
strength, which consists of two parts: the large-scale exponential
attenuation part and the small scale Rayleigh enhancement part. The
novelty of this model is the Rayleigh part, which contributes to depicting
target induced multipath components. We then explore the use of the
proposed ER model with a particle filter in the context of multi-target
localization and tracking. Finally, we demonstrate that ER model
outperforms the existing models by means of localization and tracking
experiments in different indoor and outdoor environments, which
highlights the advantages of using the Rayleigh component in mitigating

2. the multipath interferences thus improving the localization and tracking
performance.
Existing System:
A number of possible sensor technologies could be applied for the
purposes of DFLT, such as ultrasonic sensors, optical imaging sensors, light
sensors, pyroelectric infrared (PIR) sensors and so on.
Recently, there has been a growing interest in the area of building DFLT
systems with wireless sensor networks, in which localization and tracking
can be carried out by measuring of the links’ received signal strength (RSS).
In contrast to other sensor technologies, radio frequency (RF) waves can
transmit through nonmetal walls, smoke, and other opaque obstructions.
Proposed System:
In this paper, we first present our RSS model, an Exponential-Rayleigh (ER)
model, based on actual measurements from extensive experiments, which
consists of two parts: the large-scale exponential attenuation part and the
small scale Rayleigh enhancement part. The Rayleigh part involved
contributes to depicting target-induced multipath components.
Then the usage of the ER model with a particle filter is extended to achieve
multi-target DFLT. Finally, we demonstrate that proposed ER model
outperforms the existing models by means of experiments in different
indoor and outdoor environments, which highlights the advantages of

3. using the Rayleigh components in alleviating the unpredictable problem
caused by multipath interferences.
Hardware Requirements:
• System : Pentium IV 2.4 GHz.
• Hard Disk : 40 GB.
• Floppy Drive : 1.44 Mb.
• Monitor : 15 VGA Colour.
• Mouse : Logitech.
• RAM : 256 Mb.
Software Requirements:
• Operating system : - Windows XP.
• Front End : - JSP
• Back End : - SQL Server
Software Requirements:
• Operating system : - Windows XP.
• Front End : - .Net
• Back End : - SQL Server