Manual

Table Of Contents
ANSI C63.17-2006
Methods of Measurement of the Electromagnetic and Operational Compatibility of UPCS Devices
of a user interface or other communications channel commencement means. This digital hardware flag is
made active by the controller’s software implementation during the setup of the communications channel
during the frame previous to the first intended transmit frame of the communications channel.
C.2.1
C.2.1.1
C.2.1.2
The multicarrier signal generator
This implementation uses a general-purpose RF vector signal generator built within a card-based PXI
mainframe.
35, 36
The mainframe can incorporate a general-purpose Windows PC, and the generator
elements consist of a programmable RF source with a wideband modulation port, and an arbitrary
waveform generator. In this implementation, the functionality of the RF vector generator is under the
control of a program running on the on-board PC.
The RF source element has attenuators and gain stages in provision for the setting of the overall signal
level. The controlling software allows the test engineer to set the levels in individual timeslots. When the
interference profile is loaded into the arbitrary waveform generator, drivers within the controlling software
adjust the composite signal level so as to achieve the desired signal level for each of the carriers and
timeslots.
The arbitrary waveform generator element generates an IF signal incorporating the desired multicarrier
modulation, which is then applied to the RF source element. The arbitrary waveform generator is
configured with two trigger inputs and two marker outputs. The triggers inputs are used to synchronize with
the frame timing, and to change the interference profile immediately prior to the first transmit burst of a
communications channel. The two marker outputs are used to show the timing of the interference profile
change in the course of documenting the timed interference tests of the EUT.
Trigger functionality for the arbitrary waveform generator frame synchronization
The interference must be synchronized with the frame of the EUT so that time alignment with individual
slots and timing within slots is controlled. In this implementation, the arbitrary waveform generator is
programmed to make one frame of multicarrier signal, less a few microseconds. When the frame-sync
signal arrives at the trigger, the arbitrary waveform generator generates one frame, then waits for the next
trigger, which arrives in a few microseconds. Each timeslot is bracketed by idle periods, and the interval
waiting for the next frame trigger occurs during the idle period following the last timeslot of the frame, so
multicarrier signal integrity is preserved, yet small differences in the clock rates between the EUT and the
test system are removed.
Trigger functionality for the arbitrary waveform generator on interference profile
changes
The text of 7.3.4 requires that the interference profile be changed immediately prior to the first transmit
burst of the communications channel. The arbitrary waveform generator’s multiple-trigger capability is
used to make the interference profile being generated change to a second profile on the receipt of a trigger
signal. During test setup, the arbitrary waveform generator is loaded with both desired profiles, and each
trigger event received by the arbitrary waveform generator causes it to switch to the other profile.
35
This information is given for the convenience of users of this standard and does not constitute an endorsement by the IEEE of this
product. Equivalent technology may be used if it can be shown to lead to the same results.
36
PXI is a trademark of PXI Systems Alliance, Incorporated.
56
Copyright © 2007 IEEE. All rights reserved.
Licensed to Sid Sanders. ANSI order X_30788. Downloaded 11/19/2007 2:45 PM. Single user license only. Copying and networking prohibited.