Prediction technique on the effect of human motion on indoor radio wave propagation / Md. Jakirul Islam
Due to the attractive features of millimeter band, its uses are greatly expanding in the indoor wireless communication systems. As the distance between the transmitter and receiver is much shorter in indoor environments than that of the outdoor environment, the radio wave paths of the millimeter...
Saved in:
Main Author: | |
---|---|
Format: | Thesis |
Published: |
2013
|
Subjects: | |
Online Access: | http://studentsrepo.um.edu.my/8626/4/PREDICTION_ON_THE_EFFECT_OF_HUMAN.pdf http://studentsrepo.um.edu.my/8626/ |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | Due to the attractive features of millimeter band, its uses are greatly expanding in the
indoor wireless communication systems. As the distance between the transmitter and
receiver is much shorter in indoor environments than that of the outdoor environment,
the radio wave paths of the millimeter band frequencies are highly influenced by the
building materials as well as by the human movements. Ray tracing is widely used
method to characterize the radio wave propagation for the planning and establishment
of the indoor wireless network. Accurate object modeling for the realistic environment
and computational time are two classical problems of the ray tracing model. Because,
large number of rays that travels in a complex and convoluted indoor environment must
be traced. Therefore, an accurate and efficient ray tracing method is proposed here,
which is based on the surface separation, object address distribution and surface
skipping techniques. The proposed approach considers the effects of human body
movement to provide a realistic estimation of the wave propagation. Hence, an
approximated human body model is proposed to simulate the activities of humans,
whereas three dimensional (3-D) cube or cuboids are used for the remaining objects of
the simulation environment. The Red-Black tree data structure provides a faster object
retrieval mechanism while object address distribution technique prevents the
unnecessary objects to take part in intersection tests, thus accelerates the ray tracing.
Conversely, the surface separation is a novel technique that makes the tracing of the ray
paths easily and accurately, mostly for the complex 3-D environment. In addition, the
calculation of exact ray paths that reach the receiver after multiple reflections,
refractions and/or diffractions is also considered in this study. To prove the superiority,
complexity analysis and detail comparisons (based on predicted rays, computational
time and received power) between the proposed and existing methods are presented in this study. It is observed from the results that the proposed method predicts the same
amount of rays and received power as the image and Space Volumetric Partitioning
(SVP) methods, which ensures the accuracy of the proposed method. Conversely, the
proposed method predicts the higher amount of rays (it is about 10% and 2%) and
higher amount of received power (it is about 3.65% and 1.87%) compared to the Ray
Launching (RL) and Angular Z-Buffer (AZB) methods, respectively. Moreover, the
proposed method is 30.75%, 36.47, 69.30%, and 91.47% faster than the SVP, AZB,
Image, and RL methods, respectively, when the simulation was carried out in the simple
and complex environment, respectively. Additionally, the proposed method relatively
obtaining the constant time for two different environments and the simulation time does
not directly follow the number of objects of the indoor environment. The results
obtained will be of great interest for the proposed ray tracing method that involves
human motion within the simple and complex indoor environments. |
---|