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Hi
Anna,
Thank
you for providing this information. You are correct that adjacent cdma2000
carriers may be
placed
adjacent to one another. This is exactly what I had said in my
previous email below.
At the
edge of a 5 MHz licensed frequency block, there is typically a guard band of 625
kHz. As you
have
noted, this is to avoid interference to an operator in an adjacent frequency
block. With a guard band
of 625
kHz on each end of a 5 MHz block, this leaves only 3.75 MHz of spectrum, e.g.
this will allow
the
deployment of 3 cdma2000 carriers where each carrier is 1.25 MHz.
In the
case of a 15 MHz licensed spectrum block, it is possible to deploy a total of 11
cdma2000
carriers, not 12.
Additional details can be found in: Physical
Layer Standard for cdma2000 Spread Spectrum Systems
Also,
again as I had indicated in my previous email, if an operator
had a licensed allocation of only
1.25
MHz then there is no realistic way to deploy this type of
system since the necessary guard bands
would
fall out of this block and onto the adjacent operators.
Best regards,
David Shively
-----Original Message-----
From:
Lai-King Tee [mailto:a.tee@samsung.com]
Sent: Tuesday, November 25,
2003 2:03 PM
To: 'Joseph Cleveland'; 'Shively, David';
stds-80220-requirements@ieee.org
Subject: RE: stds-80220-requirements:
Spectral Efficiency (4.1.2)
Hello
David,
Based on what I found
from the reference material*, the guard band is used in the CDMA (IS-95)
system when the adjacent frequency channel may have high power signal
transmissions. However, there is no need for guard bands between adjacent CDMA
channels.
The reason that the
first CDMA 2000 channel is usually deployed further away from the edge of the
licensed band is probably to avoid high interference power from the adjacent
frequency channel that has been used for other high power wireless
systems.
*Reference: "Jerry D.
Gibson, The Mobile Communications Handbook, Chapter 27, IEEE press,
1996.
Best
regards,
Anna.
-----Original
Message-----
From:
owner-stds-80220-requirements@majordomo.ieee.org
[mailto:owner-stds-80220-requirements@majordomo.ieee.org] On Behalf Of Joseph Cleveland
Sent: Tuesday, November
25, 2003 8:53
AM
To: 'Shively,
David'; 'stds-80220-requirements@ieee.org'
Subject: RE: stds-80220-requirements:
Spectral Efficiency (4.1.2)
I
disagree with your analysis. For example, PCS
D/E/F-Block (5 MHz) operators currently use carriers separated
by 1.25 MHz with all channels assigned. If an operator has a
15 MHz block (e.g., A/B/C-Block), the operator can use the entire spectrum
with carriers placed 1.25 MHz apart across the entire block - for a
total of 12 carriers, not 9. It is realistic to deploy a system with a
chip rate of 1.2288 Mcps in a 1.25 MHz bandwidth!
-----Original
Message-----
From:
owner-stds-80220-requirements@majordomo.ieee.org
[mailto:owner-stds-80220-requirements@majordomo.ieee.org] On Behalf Of Shively,
David
Sent:
Tuesday, November 25,
2003 10:00
AM
To:
'stds-80220-requirements@ieee.org'
Subject: RE: stds-80220-requirements:
Spectral Efficiency (4.1.2)
I'm
afraid I have to disagree and this is actually an example of the point
I have tried
In
some cases, yes, cdma2000 carriers can be placed directly adjacent to one
another,
although there is
some degradation in overall capacity when this is done. However, in
most
deployments the first cdma2000 channel that is used is 1.25 MHz away from
the
edge
of the licensed band. This means that there is a guard band of
approx. 625 kHz
between the first
cdma2000 carrier and the edge of a licensees spectrum
allocation.
This
is why an operator can use 3 cdma2000 carriers in a 5 MHz block of
licensed spectrum
If an operator
had a license for only a 1.25 MHz block of spectrum, then I do not think it
would
realistic to deploy
a system with a chip rate of 1.2288 Mcps.
-----Original
Message-----
From: Joseph
Cleveland [mailto:JClevela@sta.samsung.com]
Sent: Tuesday,
November 25, 2003 9:51
AM
To: 'Shively,
David'; 'stds-80220-requirements@ieee.org'
Subject: RE: stds-80220-requirements:
Spectral Efficiency (4.1.2)
I
believe that if you look at the spectrum allocation scheme and spectrum
emission mask for CDMA2000 you will find that 1.25 MHz does include
the guard bands. The CDMA2000 channel spacing is 1.25
MHz.
-----Original
Message-----
From:
owner-stds-80220-requirements@majordomo.ieee.org
[mailto:owner-stds-80220-requirements@majordomo.ieee.org] On Behalf Of Shively,
David
Sent:
Monday, November 17,
2003 3:06 PM
To:
stds-80220-requirements@ieee.org
Subject: RE:
stds-80220-requirements: Spectral Efficiency (4.1.2)
Regarding these definitions, it should be
clearly understood whether
or not guard bands are accounted for in the
calculation of spectral
efficiency. For UMTS (W-CDMA), the channel
is usually quoted as being
5 MHz wide. In this case the guard bands
have been included. However,
for cdma2000 1X (and IS-95) the channel is
usually quoted as being
1.25 MHz wide which does not include the
necessary guard bands.
I propose the following:
Network Wide Bandwidth: The network wide
bandwidth is the total spectrum in
use by the unique carriers deployed in the
network, including any
required guard bands.
Best regards,
David Shively
-----------------------------------------------------------
Dr. David
Shively
Cingular Wireless
5565 Glenridge Connector, Mail Stop
950
Atlanta, GA 30342
Phone: 404 236
5909
Mobile: 404 285 5731
FAX: 404 236
5949
email:
david.shively@cingular.com
pager:
dshively@imcingular.com
-----Original Message-----
From: Humbert, John J
[NTWK SVCS] [mailto:JHumbe01@sprintspectrum.com]
Sent: Monday, November 17,
2003
12:08
PM
To:
stds-80220-requirements@ieee.org
Cc: mike@arraycomm.com
Subject: stds-80220-requirements:
Spectral Efficiency (4.1.2)
Below is the latest version of the text that was
developed at the Plenary in Albuquerque along with a list of the open issues for this
section.
*
4.1.2 System Spectral Efficiency (b/s/Hz/sector)
* The system
spectral efficiency of the 802.20 air interface shall be quoted for the
case of a three sector baseline configuration [Footnote 1]. It shall be
computed in a loaded multi-cellular network setting, which shall be
simulated based on the methodology established by the 802.20 evaluation
criteria group. It shall consider among other factors a minimum expected
data rate/user and/or other fairness criteria, and percentage of
throughput due to duplicated information flow. The values shall be
quoted on a b/s/Hz/sector basis. The system spectral efficiency of the
802.20 air interface shall be greater than X b/s/Hz/sector.
* Footnote
1: Since the base configuration is only required for the purpose of
comparing system spectral efficiency, proposals may submit deployment
models over and beyond the base configuration.
*
Definition:
* System
spectral efficiency - System spectral efficiency is defined as the ratio
of the aggregate throughput (bits/sec) to all users in the system
divided by the network wide bandwidth (Hz) and divided by the number of
sectors in the system.
* Aggregate
Throughput: Aggregate throughput is defined as the total throughput to
all users in the system (user payload only).
* Network
Wide Bandwidth:The network wide bandwidth is the total spectrum in use
by the unique carriers deployed in the network.
* Open items
- Single
value vs. multiple for uplink and downlink
- X
bits/sec/Hz [note 1 b/s/Hz -or- downlink > 2 b/s/Hz/(cell or sector?)
@ 3km/hr ;uplink > 1 b/s/Hz/(cell or sector?) @ 3
km/hr].
- Actual
values of spectral efficiency at higher speeds
- TDD/FDD
John J. Humbert
6220 Sprint Parkway
Mailstop KSOPHD0504 -
5D276
Overland Park, KS 66251-6118
PCS (816)
210-9611
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