Text preview for : 5989-0130EN.pdf part of HP 5989-0130EN HP Publikacje 5989-0130EN.pdf
Back to : 5989-0130EN.pdf | Home
Performing Bit Error Rate
Measurements with ADS
and Baseband Studio Streaming
Connected Solutions
Application Bulletin 1476-5
ESG signal generator DUT 896XX VSA
Baseband post-processing in ADS receiver for Coded BER
.sdf file
Baseband
Studio
Streaming file
ADS
Coded
BER Result
ADS signal source Glacier Sim.
signal source ADS receiver
Introduction
Verifying Bit Error Rate (BER) and Block Error Rate (BLER) Another challenge is that RF engineers designing RF
performance can present real challenges to RF engineers. receivers may not have access to the baseband func-
Two major factors should be considered: (1) the number tionality required to perform coded BER measurements,
of bits required to produce a statistically meaningful BER/ which can present a barrier to verifying coded BER - a key
BLER result, and (2) the baseband functionality required to receiver design specification with today's digital communi-
verify coded BER/BLER. cations signal formats.
Arbitrary waveform generator (Arb) based solutions allow The Connected Solutions application described in this
waveforms to be downloaded from simulation to the signal note can help in verifying RF BER performance when a
generator Arb for BER/BLER testing, but are limited by the large number of data bits are required to achieve a statis-
Arb depth of the signal generator. Depending on the appli- tically meaningful BER result.
cation, this may or may not be sufficient.
Concept
A conceptual flow diagram is shown on page 1. The ADS sim- used to post-process the data to compute BER or PER. The
ulation signal can be stored to a Baseband Studio Streaming 89601 VSA software with option 105 is useful for reading the
data file using a new file writing capability available in ADS recorded signal back into simulation and for performing RF
2003C. The amount of data to be streamed out of the ESG measurements such as error vector magnitude (EVM) in ADS.
is determined by the hard disk storage size to store the
Baseband Studio Streaming file.
Verifying Coded BER/PER Performance
After the ADS simulation has been run and the binary
Baseband Studio Streaming file is created, the signal is One of the key challenges of verifying coded BER/PER per-
streamed to the ESG using Baseband Studio Streaming to formance of RF hardware is that the baseband functionality
turn the simulated signal into a real RF test signal. required for coded BER/PER may not be available for testing.
For example, performing a coded BER measurement for 3GPP
The RF test signal is input into the device under test (DUT), W-CDMA requires that the baseband functionality to perform
which could be an RF component or a receiver RF front-end. such tasks as de-scrambling, de-spreading, de-interleaving,
The DUT output is captured using a Vector Signal Analyzer de-multiplexing, and so on, are required to recover the data
(896XX VSA) to record an sdf file (.sdf). After the sdf record- bits from the measured signal so that a BER measurement
ing is read into ADS, the signal can be post-processed with can be performed. This can present a potential barrier if the
a simulation baseband receiver (for example, WLAN or RF hardware being tested does not include that baseband
WCDMA) to compute the coded BER or Packet Error Rate functionality.
(PER).
This Connected Solutions application uses the Wireless
Design Libraries in ADS to perform the post-processing on
Test Setup Overview the measured signal so that coded BER/PER can be mea-
sured.
This application uses the new Baseband Studio file writer
in ADS 2003C and the Connection Manager. An E4438C An example of a coded WCDMA BER measurement with fad-
Electronic Signal Generator (ESG) with the Baseband Studio ing is performed with ADS and Baseband Studio Streaming,
Streaming card, option 602, is required for streaming large with 1000 frames (or 10 seconds) of data streamed out of the
amounts of data from the ADS-created file to the ESG output. ESG from a file created by ADS with the simulated fading.
The ESG output is captured with an 89641 VSA and read back
An 896XX VSA with option 288 is used to capture the IQ into ADS for the BER measurement. The results are shown in
waveform to read back into ADS. The ADS wireless design Figure 1.
libraries, such as the WCDMA or WLAN design library, can be
Figure 1. BER/BLER results for data streamed out of the ESG, captured with a VSA, and read back into ADS to obtain the measurements.
2
Summary Resources
Connected Solutions can help with performing coded BER/ Connected Solutions Web Page:
PER measurements when a large number of data bits are
required for the BER/PER measurement. This application For more information about Agilent Technologies' connect-
is useful for RF component testing or for RF subsystem ed solutions, including additional application notes and a
testing, such as testing a receiver front-end. ADS Design configuration guide, visit:
Libraries provide the necessary baseband post-processing www.agilent.com/find/eesof-connectedsolutions
to perform coded BER and PER
measurements. Agilent EEsof EDA Home Page:
For more information about Agilent EEsof EDA, visit:
Required Equipment/Software www.agilent.com/find/eesof
E8900A/AN ADS 2003C Agilent Baseband Studio:
E5720A/AN Connection Manger
E8850A/AN Communications System Designer For more information about Agilent Baseband Studio, visit:
E8875A/AN 3GPP W-CDMA Design Library (optional) www.agilent.com/find/basebandstudio
E8874A/AN WLAN Design Library (optional)
E4438C ESG with option 602
896XXA VSA Software with option 288, 100, AYA, 105, B7N
for 3GPP W-CDMA, B7R for WLAN
3
www.agilent.com
For more information on Agilent Technolo-
Remove all doubt gies' products, applications or services,
please contact your local Agilent office.
Our repair and calibration services The complete list is available at:
will get your equipment back to you, www.agilent.com/find/contactus
performing like new, when prom-
ised. You will get full value out of Americas
your Agilent equipment through- Canada (877) 894-4414
out its lifetime. Your equipment Latin America 305 269 7500
will be serviced by Agilent-trained United States (800) 829-4444
technicians using the latest factory
calibration procedures, automated Asia Pacific
Australia 1 800 629 485
repair diagnostics and genuine parts.
China 800 810 0189
You will always have the utmost
Hong Kong 800 938 693
confidence in your measurements.
India 1 800 112 929
For information regarding self main- Japan 0120 (421) 345
tenance of this product, please Korea 080 769 0800
contact your Agilent office. Malaysia 1 800 888 848
Singapore 1 800 375 8100
Agilent offers a wide range of ad- Taiwan 0800 047 866
ditional expert test and measure- Thailand 1 800 226 008
ment services for your equipment,
including initial start-up assistance, Europe & Middle East
onsite education and training, as Austria 01 36027 71571
well as design, system integration, Belgium 32 (0) 2 404 93 40
and project management. Denmark 45 70 13 15 15
Finland 358 (0) 10 855 2100
For more information on repair and France 0825 010 700*
calibration services, go to: *0.125 /minute
Germany 07031 464 6333
www.agilent.com/find/removealldoubt Ireland 1890 924 204
Israel 972-3-9288-504/544
Italy 39 02 92 60 8484
Netherlands 31 (0) 20 547 2111
Product specifications and descriptions Spain 34 (91) 631 3300
in this document subject to change Sweden 0200-88 22 55
without notice. Switzerland 0800 80 53 53
United Kingdom 44 (0) 118 9276201
Other European Countries:
www.agilent.com/find/contactus
Revised: October 6, 2008