1. <month year>
doc.: IEEE a
Nov 2005
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Limitations of the channel and potential problems to the system design]
Date Submitted: [13 Nov, 2005]
Source: [Su-Khiong Yong]
Company [Samsung Advanced Institute of Technology (SAIT)]
Address [RF Technology Group, Comm. & Networking Lab., P. O. Box 111, Suwon , Korea]
Voice:[ ], FAX: [ ],
Re : [IEEE c Channel modeling]
Abstract: [Limitations of the channel and potential problems to the system design]
Purpose:[This document discusses the propagation issues and parameters for IEEE c]
Notice :This document has been prepared to assist the IEEE P 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 P
Su-Khiong Yong, Samsung-SAIT
<author>, <company>

2. Limitations of the Channel and Potential Problems to the System Design
<month year>
doc.: IEEE a
Nov 2005
Limitations of the Channel and Potential Problems to the System Design
Su-Khiong Yong
Samsung Advanced Institute of Technology (SAIT), Korea
Su-Khiong Yong, Samsung-SAIT
<author>, <company>

3. Outline Objectives Current Status / View Limitations of the Model
<month year>
doc.: IEEE a
Nov 2005
Outline
Objectives
Current Status / View
Limitations of the Model
The Potential Problems
Conclusions
Su-Khiong Yong, Samsung-SAIT
<author>, <company>

4. <month year>
doc.: IEEE a
Nov 2005
Objectives
To response to the call for selecting a “simplified model” during the Garden Grove meeting.
To discuss what are the potential problems that could be generated.
Su-Khiong Yong, Samsung-SAIT
<author>, <company>

5. Nov 2005
Current View
Due to the tight time line, there was a suggestion to change the modeling plan to a “simplified” version. The below channel models were described
IBM data, journal papers, etc (call model A)
Channel Model as a function of antenna gain (IBM or Some Additional Measurement) (call model B)
Channel model that can meet 03/06 deadline with AoA (Delay in CFP) NICTA, UMass (call model C)
So what are the potential problems associated with this model B?
Su-Khiong Yong, Samsung-SAIT

6. What Are the Limitations of Model B?
Nov 2005
What Are the Limitations of Model B?
What does it mean channel model as a function of antenna gain?
To have that model,
Perform endless measurements with different antenna setups
Resort to a double directional channel measurement and modeling
So, the model B mentioned will only valid for that specific antenna setup. You can’t do anything about it, so it is not a function of antenna gain rather it is valid for a fixed value of the antenna gain of the specific antenna used.
This model is not sufficiently generic.
Su-Khiong Yong, Samsung-SAIT

7. Nov 2005
What Are the Problems?
At 60GHz, specular reflections are the primary mode of propagation, while diffuse reflections and diffraction do not contribute significantly to the received power.
Also, we know that at 60GHz, signals undergo severe path loss and transmission loss due to walls, partitions, furniture etc.
Su-Khiong Yong, Samsung-SAIT

8. What Are the Problems (cont)?
Nov 2005
What Are the Problems (cont)?
Using the model B with a specific antenna setup, what will happen if the antenna in one end link is misaligned in LOS condition? This situation is common as user does not suppose to handle where to direct the antenna.
Our target is not only for the scenario where the Tx and Rx are pointed to each other and it is also hard to guarantee the LOS condition in indoor environment e.g. typical office.
Su-Khiong Yong, Samsung-SAIT

9. What Are the Problems (cont)?
Nov 2005
What Are the Problems (cont)?
So we will have no idea what will happen to the channel characteristics if the antennas are misaligned as paths might arrive from other directions with much higher power
Su-Khiong Yong, Samsung-SAIT

10. Nov 2005
Perfect Alignment
The radiation pattern of each antenna is pointed towards the AOA or AOD of the most significant path
M. Williamson et. al, “Investigating the Effects of antenna directivity on wireless indoor communications at 60GHz, IEEE PIMRC 97
Su-Khiong Yong, Samsung-SAIT

11. Misalignment Nov 2005 30o Tx and Omni Rx
M. Williamson et. al, “Investigating the Effects of antenna directivity on wireless indoor communications at 60GHz, IEEE PIMRC 97
Su-Khiong Yong, Samsung-SAIT

12. Effect of Rotating the Antenna on the RMS Delay Spread
Nov 2005
Effect of Rotating the Antenna on the RMS Delay Spread
LOS condition is at 72o
M. Williamson et. al, “Investigating the Effects of antenna directivity on wireless indoor communications at 60GHz, IEEE PIMRC 97
Su-Khiong Yong, Samsung-SAIT

13. Effect of Rotating the Antenna on the K-Factor
Nov 2005
Effect of Rotating the Antenna on the K-Factor
M. Williamson et. al, “Investigating the Effects of antenna directivity on wireless indoor communications at 60GHz, IEEE PIMRC 97
Su-Khiong Yong, Samsung-SAIT

14. This may happen in other angles which will need to know.
Nov 2005
But in NLOS we could see that it is not necessary for the direct pointing angle of the Tx-Rx will give the lowest RMS delay spread and highest K-factor.
This may happen in other angles which will need to know.
Su-Khiong Yong, Samsung-SAIT

15. Nov 2005
Conclusions
We need to properly characterize the channel before we can design a reliable system
It seems that channel model B will not be able to address some of the important criteria for performance evaluation.
The directional information (at least in one link) is a must.
Su-Khiong Yong, Samsung-SAIT