December 2006
doc.: IEEE 802.22-06/0202r01
IEEE P802.22
Wireless RANs
Sensing Tests
Date: 2006-10-06
Author(s):
Name
Winston
Caldwell
Victor
Tawil
Gerald
Chouinard
Company
FOX
MSTV
Communications
Research Centre
Address
10201 W. Pico Blvd.
Los Angeles, CA 90064
4100 Wisconsin Ave.. NW
Washington, DC 20015
3701 Carling Ave.
Ottowa, Canada K2H-8S2
Phone
email
310-369-4367
Winston.caldwell@fo
x.com
202-966-1956
Vtawil@mstv.org
613-998-2500
Gerald.chouinard@cr
c.ca
Abstract
The test plan for evaluating sensing techniques in the laboratory is provided. The test plan
encompasses a number of tests to determine the performance of the unlicensed device in the presence
of incumbent signals. This involves a threshold of detection (sensitivity) test in the presence and
absence of strong Incumbent taboo (adjacent) channels, and other related tests to determine the various
factors that may affect performance of the unlicensed device such as the front end, theAGC, the device
noise figure, etc.
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Submission
page 1
Winston Caldwell, FOX
December 2006
doc.: IEEE 802.22-06/0202r01
802.22 Sensing Tests
Introduction
(Text to better explain the purpose of this document and why it is needed. A short
description of the various factors that may affect the performance of a sensing
device)
{Need to specify that the testing is limited to detecting a TV channel in 6 MHz bandwidth, i.e. fine detection
sensing only}
In order to test the sensing techniques correctly and completely, the sensing “black box” should not be de-coupled
from the RF front-end that is intended to be used in the CPE. However, because the RF front-end has not yet
been designed and built, a temporary “first-look” procedure is presented to test the sensing techniques in the lab.
Until the RF front-end is built, the sensing “black box” will have to be examined in operation with a modelled RF
front-end. Unfortunately, it will not be possible to model numerous forseen and unforeseen RF front-end effects
(i.e., third-order intermodulation) while following the sensing test procedures described in this document.
1- Threshold of Detection (Sensitivity) Test
Purpose:
Test the ability of the sensing device to correctly determine that an incumbent co-channel signal is present in the
presence of RF noise. This test should conclude at what minimum S/N the device can properly function.
Conditions:
 False alarm: Incorrectly determines that an incumbent signal is present when in fact, it is not present.
 Misdetection: Incorrectly determines that an incumbent signal is not present.
Variables:
 Sensing period
 Incumbent signal power level
 Noise power level
 Frequency offset to model LO inaccuracies
 Phase offset
Sensing test block diagram
Submission
page 2
Winston Caldwell, FOX
December 2006
doc.: IEEE 802.22-06/0202r01
Description a test procedure to determine the threshold of detection of the black box
 (Move Section 5.3 in document 802.22-06-028/r10 “Spectrum Sensing Simulation Model” and
modify where appropriate)
2- Sensing capabilities with a Strong taboo (Adjacent) Channel TV Signals
Purpose:
Test the performance of the sensing device in the presence of a strong incumbent taboo (adjacent) channel TV
signals.
Conditions:
 False alarm: Incorrectly determines that an in-channel incumbent signal is present when in fact, it is not
present. The device would be affected by the energy leaking in-channel from the strong (taboo) adjacent
channel.
 Misdetection: Incorrectly determines that an in-channel incumbent signal is not present. The device does
not detect the in-channel signal because the energy that has leaked into the channel from the strong taboo
(adjacent) channel which hides the weaker in-channel incumbent signal. { COMMENT: this situation is
unlikely}
Variables:
 Sensing period
 In-channel power
 Taboo (Adjacent) channel power
 Noise power level
 Frequency offset to model LO inaccuracies
 Phase offset
{Develop a test procedure for taboo channel false detection}
 (Repeat test in section 1 with introduction of strong taboo signals and compare the two results)
3. AGC Capabilities
Purpose
Test the capability and behavior of the AGC of the unlicensed device. Determine the effect of varying levels of
in-channel signal power and noise power on the AGC. Also test the inter-modulation effects of the AGC in the
presence of a strong adjacent channel TV signal.
Variables:
 Sensing period
 In-channel power
 Adjacent channel power
 In-channel noise power
(to be determined)
Multi-path Test ?????? (Propose to delete)
This test should evaluate the capabilities of the sensing device in the event of multi-path. Multi-path should have
some effect on a sensing device that relies upon feature detection to detect the presence of a signal and to identify
an incumbent signal.
Variables:
 Sensing period
 In-channel power
Submission
page 3
Winston Caldwell, FOX
December 2006



doc.: IEEE 802.22-06/0202r01
Adjacent channel power
In-channel noise power
Multi-path conditions
Sensing RF front-end performance????
Noise Figure Measurements
Test the NF of the sensing RF front-end through frequencies ranging from L-VHF to upper UHF.
Impedance
Test the impedance of the sensing RF from-end through frequencies ranging from L-VHF to upper UHF.
Submission
page 4
Winston Caldwell, FOX