March, 2008 IEEE P802.15-02/368r5-SG3a
Submission Page 1 Jeff Foerster, Intel R&D
IEEE P802.15
Wireless Personal Area Networks
Project
IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
Title
Channel Modeling Sub-committee Report Final
Date
Submitted
[18 November, 2002]
Source
[Jeff Foerster, Sub-committee Chair]
[Intel R&D]
[JF3-206
2111 N.E. 25
th
Ave.
Hillsboro, OR 97124]
Voice: [503-264-6859]
Fax: [503-264-3483]
E-mail: [jeffrey.r.foerster@intel.com]
Re:
[]
Abstract
[]
Purpose
[The purpose of this report is to summarize the work of the channel modeling sub-
committee and provide some final recommendations on how the channel model
can be used to help evaluate PHY submissions to IEEE 802.15.3a.]
Notice
This document has been prepared to assist the IEEE P802.15. It is offered as a
basis for discussion and is not binding on the contributing individual(s) or
organization(s). The material in this document is subject to change in form and
content after further study. The contributor(s) reserve(s) the right to add, amend or
withdraw material contained herein.
Release
The contributor acknowledges and accepts that this contribution becomes the
property of IEEE and may be made publicly available by P802.15.
March, 2008 IEEE P802.15-02/368r5-SG3a
Submission Page 2 Jeff Foerster, Intel R&D
Channel Modeling Sub-committee Report (Final)
Date: December 3, 2002
This report has been approved by the study group IEEE 802.15.SG3a for use as a method to
evaluate the physical layer performance of proposals expected to be submitted to the IEEE
802.15.3a task group.
Revision History of Final Recommendations
Revision Number
Date
Comments
1.0
12/03/2002
Creation of first version of FINAL recommendations.
Previous revisions of document 02/368 (revisions 1-4)
represented working DRAFT documents and do not
constitute final recommendations.
March, 2008 IEEE P802.15-02/368r5-SG3a
Submission Page 3 Jeff Foerster, Intel R&D
Table of Contents
1 INTRODUCTION .................................................................................................................4
1.1 DESIRED CHARACTERISTICS OF CHANNEL MODEL .............................................................4
2 NARROWBAND CHANNEL MODEL ..............................................................................5
3 UWB CHANNEL MODEL...................................................................................................5
3.1 SUMMARY OF MEASUREMENTS AND PROPOSED MODELS...................................................5
3.1.1 “The Ultra-wideband Indoor Path Loss Model,” S. Ghassemzadeh and V. Tarokh
[1] 6
3.1.2 “Empirically Based Statistical Ultra-Wideband Channel Model,” M. Pendergrass
[2] 6
3.1.3 “UWB Channel Modeling Contribution from Intel,” J. Foerster and Q. Li [3].....7
3.1.4 “A proposal for a selection of indoor UWB path loss model,” G. Shor, et. al. [4] 7
3.1.5 “Radio Channel Model for Indoor UWB WPAN Environments,” J. Kunisch and J.
Pamp [5] 8
3.1.6 “The Ultra-wideband Indoor Multipath Loss Model,” S. Ghassemzadeh and V.
Tarokh [6]................................................................................................................................9
3.1.7 “The Ultra-Wide Bandwidth Indoor Channel: from Statistical Model to
Simulations,” A. Molisch, M. Win, and D. Cassioli [7] ..........................................................9
3.1.8 “Evaluation of an Indoor Ultra-Wideband Propagation Channel,” J-M Cramer,
R. Scholtz, and M. Win [8] ......................................................................................................9
3.1.9 “UWB Propagation Phenomena,” Kai Siwiak [9]..................................................9
3.1.10 “Propagation notes to P802.15 SG3a from IEEE Tutorial,” Kai Siwiak [10].....10
3.2 PROPOSED UWB CHANNEL MODEL.................................................................................10
3.2.1 Path Loss Model ....................................................................................................10
3.2.2 Multipath Model ....................................................................................................11
3.3 REALIZATIONS FROM CHANNEL MODEL ..........................................................................13
3.3.1 Channel characteristics desired to model .............................................................13
3.3.2 Discrete Time Model..............................................................................................14
3.3.3 How to handle different sample times ...................................................................14
3.3.4 Channel Realizations .............................................................................................15
3.4 TIME VARIABILITY OF CHANNEL .....................................................................................31
3.5 HOW TO USE THE MODEL AND REALIZATIONS .................................................................31
3.5.1 Meeting the Selection Criteria...............................................................................31
3.5.2 Level of disclosure desired by PHY proposals ......................................................31
4 LIST OF CONTRIBUTORS ..............................................................................................32
5 REFERENCES ....................................................................................................................32
March, 2008 IEEE P802.15-02/368r5-SG3a
Submission Page 4 Jeff Foerster, Intel R&D
APPENDIX...................................................................................................................................33
1 Introduction
The purpose of this report is to summarize the final recommendations of a channel modeling
sub-committee that was formed to establish a commonly agreed upon channel model that could
be used to evaluate the performance of physical (PHY) layer proposals to the IEEE 802.15.3a
task group. Since many companies plan on submitting PHY proposals using the newly legal
UWB frequency spectrum, a new channel model needed to be created that would help evaluate
the performance of these systems in realistic channels, since no well-known model existed at the
time the sub-committee was created. Also, for completeness, a narrowband channel model is
also defined, based upon a previously used and well-known model, for evaluating the
performance of proposals using a narrowband systems in the 2.4 GHz, 5 GHz, 60 GHz, or other
unlicensed spectrum.
The establishment of a channel model for IEEE 802.15 Study Group 3a High Rate WPAN
alternative PHY presented a number of challenges. These challenges included the creation of
sufficient and accurate criteria for comparing proposals while keeping the model relatively
simple and straightforward to allow implementation in a short period of time.
A sub-committee was formed which established an open approach and process to include as
broad a set of perspectives as possible including a general call for proposals, presentations,
meetings in conjunction with 802.15 SG3a sessions, conference calls and email reflector traffic.
Assignment and tracking of action items were used to maintain focus and assure key issues were
addressed. There was a constant theme of creating a platform for comparison vs. a complete and
exhaustive treatment of channel model characteristics.
The fundamental parameters to be included in the model were path loss and multipath in a
variety of environments (office and residential as well as LOS and NLOS as a function of
distance). The aspects of multipath such as delay spread, decay profiles, number of paths and
associated thresholds presented the most challenge. Various models were presented based on
significant data collection efforts and assessment was made of the best fit given the objectives
for establishing comparison criteria. This data driven effort helped establish key parameters of
the model.
Results of the sub-committee’s efforts are captured through formal posting of presentations, links
to measurement databases, minutes of meetings and conference calls as well as email reflector
history. Analysis and realizations of the channel model with standard tools such as MATLAB
are also available along with information on how to use the model.
Significant appreciation goes to all contributors from commercial, research and academic
organizations around the world that made the channel model represented here a reality.
March, 2008 IEEE P802.15-02/368r5-SG3a
Submission Page 5 Jeff Foerster, Intel R&D
For completeness, since the IEEE 802.15.3a task group is expected to consider both UWB based
physical layer proposals as well as narrowband based proposals (i.e., using the 2.4 GHz or 5 GHz
unlicensed bands), both channel models are included in this report.
1.1 Desired characteristics of channel model
The goal of the channel model is to capture both the path loss and multipath characteristics of
‘typical’ environments where IEEE 802.15.3a devices are expected to operate. The model
should be relatively simple to use in order to allow PHY proposers to use the model, and, in a
timely manner, evaluate the performance of their PHY in ‘typical’ operational environments. In
addition, it should be reflective of actual channel measurements. Since it may be difficult for a
single model to reflect all of the possible channel environments and characteristics, the group
chose to try and match the following primary characteristics of the multipath channel:
� RMS delay spread
� Power decay profile
� Number of multipath components (defined as the number of multipath arrivals that are
within 10 dB of the peak multipath arrival)
Note that the actual channels resulting from the model may have several paths that are much
weaker than 10 dB from the peak, while the above characteristic was simply used to compare to
measurement results.
2 Narrowband Channel Model
For physical layer proposals using a narrowband channel in the 2.4 GHz, 5 GHz, 60 GHz, or
other unlicensed spectrum, a narrowband channel model is described here based upon the IEEE
802.11 channel model using an exponentially decaying, Rayleigh fading tap delay line (TDL).
This model assumes that each of the channel taps is drawn from an independent complex
Gaussian random variable with an average power profile that decays exponentially. The
probability distribution of the k-th tap of the channel impulse response h
k
is given by
)
2
1
,0()
2
1
,0(
22
kk
jNN
��
�
, where
)
2
1
,0(
2
k
N
�
is a zero-mean Gaussian random variable with variance
2
2
1
k
�
, k = 1, …, k
max
=
� �
sRMS
T
�
10
,
RMS
�
is the RMS delay spread, and T
s
is the sampling time.
The energy of each channel tap is given by:
RMSs
kT
k
e
�
��
�
�
2
0
2
,
where
2
0
�
is chosen in such a way as to ensure that average received energy is unity:
