Agilent 89600 Series Vector Signal Analysis Software
89601A/89601AN/89601N12
Technical Overview
• Reach deeper into signals
• Gather more data on signal problems
• Gain greater insight
From simulation to antenna
Introduction
This technical overview covers the features, capabilities, and benefits of the
89600 Series vector signal analysis software. For detailed specifications, please
see the 89600 Series Vector Signal Analysis Software Data Sheet, publication
number 5989-1786EN.
Advanced Digital Signal Processing to Uncover
and Identify Problems
Stream
Measured
data from
supported
hardware
platform
Figure 1. The VSA software architecture provides DSP demodulation algorithms with user-controlled modulation
parameters for flexible demodulation of a range of new and emerging formats, including 3G, WLAN, and 802.16.
Data can come from several sources, including multiple supported hardware platforms, recorded files, and
stream data from Agilent EEsof’s ADS simulation software.
interface
Resample
(arbitrary
spans)
Recorded
file
Time
corrections
Average
Analog
demod
(PC Windows
Time
gating
Measurement
calculations
math
registers
User
Data
®
2000 or XP Professional)
Window FFT
Display
Tra c e
data &
trace
format
In RF/wireless communications applications, the Agilent 89600 vector signal analysis
software lets you characterize complex, time-varying signals with detailed and simultaneous spectrum, modulation and time waveform analysis. Use these tools to uncover
system problems—problems you really need to see and track down.
The 89600 VSA software connects your measurement hardware to your PC
environment, using familiar, PC-based tools, providing a tightly linked software/
hardware test and measurement environment. Use these tools to track down
problems at any stage of your design process: from simulation to final prototype.
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More than spectrum analysis
The 89600 VSA software provides traditional spectrum displays and
measurements, but today, spectrum analysis isn’t enough. New digital formats
require new measurements.
Familiar tools such as spectrum analyzers with demodulation may indicate that a
problem exists, but they can’t help you understand the cause of the problem. For
instance, incorrect filtering, spurious interference, incorrect interpolation, DAC
overflow, symbol mis-timing and other errors may all increase adjacent channel
power and distort the constellation. So how do you determine what the real
problem is?
The 89600 VSA software provides you the tools to identify the root cause of the
problem and to analyze continually changing phase, magnitude, and frequency.
Some tools, like the constellation and vector diagrams, are familiar to radio
designers. Others, like the spectrogram display are tools for qualitatively understanding system behavior. And still others, like error vector time and spectrum, are
entirely new measurements bringing new capabilities and requiring new displays.
PC-based for ease-of-use
The 89600 software relies on a PC for its processing. Improvements in PC capabilities
automatically improve the VSA software’s performance. New capabilities for
integrating test instrumentation and design automation software are also made
possible because the VSA software can accept measurement data from a wide
range of supported hardware platforms, or time series data from computational
tools—and all with a familiar, easy-to-use Windows GUI.
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Vector Signal Analysis (Option 200)
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Option 200 is a required option that provides the baseline capability for the 89600
VSA software.
Powerful display formats, signal recording and playback, plus superlative help text
provide you with the tools you need for analyzing signals.
Precise analog demodulation
Figure 2. This FM demodulation of a transmitter at turn-on shows the frequency settling characteristics.
Use AM or PM demodulation to show amplitude and phase settling performance as well.
Characterize amplitude-modulated, frequency-modulated, and phase- modulated
signals in both the frequency and time domains with the built-in analog
demodulation capabilities of the 89600 VSA software.
Use analog demodulation to analyze unintentionally modulated signals.
For example:
Use FM and PM demodulation to examine phase and frequency
trajectories during frequency hops or establish the phase-lock-loop
lock-up time of oscillators and synthesizers.
AM demodulate a burst signal to evaluate the time needed for the
signal to stabilize.
AM and PM demodulate sidebands to determine the type of modula tion present in phase noise.
Take the FFT of a demodulated AM/FM/PM noise signal for insight
into spurious signals coupling through from other parts of the
circuit. Often just the frequency alone of interfering AM/FM/PM
modulation provides information about the root cause of the
interference.
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Flexible vector analysis tools
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Analyze time, frequency, and amplitude domain behavior and more with one of
the most complete set of vector and scalar analysis tools on the market today.
Measurements include:
Time
Gated time
Spectrum
Power spectral density
CCDF and CDF
Auto-correlation
Use the time tools to measure pulse width, rise and fall times, and observe the
shape of your TDMA signals. These tools are particularly useful for setting the
trigger level, hold-off and delay on your pulsed signals.
Use the spectrum tools to find the center frequency and bandwidth of your signal,
find spurs, and more. A complete set of marker and time gating functions complement the spectrum display.
Figure 3. Look at time and frequency characteristics of your signal simultaneously. The top display shows
the time trace of a bursted signal with gate markers on the second part of the burst. The bottom display
shows the frequency spectrum of just the portion of the signal in-between the gate markers.
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Statistically-based amplitude measurements provide a better description of system
or component behavior on noise-like digital communications signals. Measure
peak to average power ratio and more with the complementary cumulative distribution function (CCDF), probability distribution function (PDF) and cumulative
distribution function (CDF) tools provided in Agilent’s VSA software.
Figure 4. Both CCDF and CDF functions are available. The CCDF marker readout at the bottom of the display
indicates that the signal exceeds 9.56 dB above the average signal level only .003% of the time, useful
information when calculating design headroom.
Display format and scaling
Figure 5. Example trace formats available.
Scale your display the way you want it, with the units you need using the flexible
display formatting and scaling tools provided standard in the 89600 VSA software.
Select from a complete list of formats including log and linear displays of the signal
magnitude, displays of only the real (I) or imaginary (Q) part of the signal, vector
and constellation displays, eye displays, trellis displays and group delay. Scaling is
automatic with manual override provided for all parameters, including reference
level and units per division for both the X and Y-axes.
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See six screen displays, simultaneously
Figure 6. Display one, two, three, four, or six displays, simultaneously. You can choose to have them
appear stacked, or in a symmetrical grid.
Spectrogram display format
Figure 7. View the spectral behavior of wide bandwidth hopping signals over time using spectrogram
displays. Grey-scale views provide even greater resolution.
Take advantage of the spectrogram display to view the behavior of your signal over
time. This three-dimensional display is noted for its ability to track the frequency
and amplitude behavior of signal, particularly frequency hopping signals and signals
with poor signal-to-noise ratio. Use it to also survey signal environments for a
quick pictorial view.
For a more in-depth view, use scale markers to expand a portion of the display.
Offset and delta markers provide detailed timing information on signal events.
Use them to determine time differences between events in both the time and
frequency domains.
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Signal capture and playback
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Figure 8. The signal recording user interface is familiar and simple to use.
The 89600 VSA software lets you capture your digitized signal in your measurement hardware and transfer it directly to your PC’s disk drive. You can play the
signal back at a later time, import it into other applications, and create and play
your own recording through an Agilent signal generator.
Why record signals?
No gaps – offers continuous time record at full bandwidth of your hardware.
Provides powerful post processing with more control over the analysis.
Allows slow playbacks with overlap processing. Overlap processing allows you
to vary the amount of new information included in each display update. The
end result is to provide a “slow motion” view of your signal—extremely useful
in understanding transients and transitions.
Offers porting of simulations back to design software.
Allows you to archive – saving signal records for future analysis.
You have full control of the playback including:
Start and pause
Drag the bar to any position in the record to begin playback
Back up and rewind
Loop the recording
Set start and stop times
Re-record
Set span and center frequency (within the extent of the original capture)
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Signal generator download control
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Record a time domain signal using the recording feature, and link it to a supported
Agilent signal generator. You can record the signal at one frequency, and using
the zoom mode feature, transfer the signal to the generator at a different frequency.
For ease of use, you can control key features of the signal generator from the
89600 VSA software front panel.
Trace math
Figure 9. Create math functions for simple tasks like unit scaling, or for sophisticated new measurements
like this Barker code cross correlation function.
Math functions let you create mathematical expressions that operate on trace
data. Use math functions to:
Perform mathematical operations on trace data.
Create a mathematical expression that you can apply as a filter to a waveform.
Manipulate data in the data registers.
Math functions can be simple or complex. For example, a simple math function
may add two data registers. Another math function may compute the inverse FFT
of channel 1 spectrum-data. Or a more complex math function may combine
operations on trace data or data registers.
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Easy-to-Use Windows Graphical User Interface
Figure 10. Marker-based measurements, such as band power (shown here) or time gating, or several
others, are easy to set up. Just position the marker cursor by dragging and dropping, or type in numeric
values manually.
Changing parameters such as center frequency, span, or scale, is easy. Simply place
the cursor on the display annotation, and a special cursor will appear. Double
click and enter the parameter or use the up/down arrows. If you are familiar with
Microsoft Windows® applications, you can quickly master the 89600 VSA software.
Versatile markers highlight signal behavior
The 89600 VSA offers markers which: display current location, calculate offset
(delta) values, provide frequency counter capability, integrate between two lines
to determine bandpower, calculate occupied bandwidth (OBW), let you set up
zones to calculate adjacent channel power (ACPR), and conduct limit tests.
To display signal parameters using the marker function, simply place a marker on
the highest signal using the marker search functions. The marker parameters are
shown at the bottom of the display. Use the offset marker to measure parameters
between two points on the display.
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The ACPR marker allows you to easily perform generic adjacent channel power
ratio measurements. You can configure the reference channel and up to five
separate adjacent channels. Measurement results are displayed at the bottom
of the display, or in the ACP Summary table.
Figure 11. ACPR measurement with summary table enables you to specify up to five adjacent channels.
The OBW marker allows you to easily perform occupied bandwidth measurements.
The OBW measurement determines the band of frequencies that contain a specified
percentage of the total power within the measurement span.
Figure 12. The OBW measurement with summary table can determine the centroid frequency, or you can
manually set the centroid frequency to the center frequency.
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Limit lines can be created to compare trace data to your defined limits and indicate
a pass or fail condition.
Figure 13. Set the pass and fail color indication for either the limit, or the margin, or both. You define your
own limits using the built-in limit line editor.
These more sophisticated marker measurements allow more sophisticated setup.
For example, you define a table of values, as for ACPR or simple limit tests. For
more complex limit tests, you can either define a set of limit points segment by
segment, or import a measurement and add a margin limit around it. For all of
these and other markers, the results are displayed at the bottom of the display.
Markers can be coupled across all six displays, allowing you to “walk” through your
signal and see its behavior in multiple domains—a very powerful and useful feature.
Highlight signals
For a closer look at a signal, use the highlight box to enhance signal viewing by
scaling traces in. Place the box around the signal of interest and select the
desired scaling. You can scale both the X- and Y-axis, or scale each separately.
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Multi-channel ready
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The 89600 VSA software comes fully equipped to control and process two base
band or two RF channels.
The built-in ch1 + jch2 mode combines two base band channels for automatic
analysis of a single, composite signal. All measurements, including spectrum,
time, and error analysis, are available on the
combined signal.
Powerful and sophisticated trace data provide you with the basic
capabilities to perform even MIMO-analysis:
Auto-correlation and cross-correlation
Coherence
Frequency response
Impulse response
Use these tools to develop and analyze complex multi-antenna, radar, or signal
surveillance systems. If you’re working on IEEE 802.11n MIMO systems, Option
B7Z takes full advantage of the software’s
capability. For more information see the B7Z section.
Check hardware specifications to determine which hardware platform configurations support multiple channels.
Spectrum analyzer application
The 89600 VSA software includes a spectrum analyzer application.
Use this application to identify signals present in a wide span and to evaluate
small signals very close to the noise floor. This application makes scalar measurements, as opposed to vector measurements. Scalar measurements provide displays of amplitude versus frequency for both narrow and wide spans.
Scalar measurements step the application's local oscillator (LO) during the measurement. Each step of the LO produces a segment of the selected frequency
span. In other words, the application sets its LO, performs an FFT, then steps its
LO to a higher frequency, performs another FFT, and so forth. Because of this, not
all hardware measurement platforms support the use of the spectrum analyzer
application.
Use this application when you need:
Very narrow resolution bandwidth with high speed
Very low noise floor with wide spans
High signal-to-noise dynamic range
Maximum flexibility of frequency span, resolution bandwidth, and speed
Wider frequency spans
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Help text
Figure 14. Everything, from reference information, to tutorials using recorded signals, to programming
examples, is included in the incredibly comprehensive help text.
Over 5000 equivalent paper pages of help text, application information and tutorials
are provided with the 89600 software. A complete set of search tools and hot links
provide ready access to all of this information.
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Powerful Modulation Analysis Options
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The real power of the VSA software is its ability to analyze complex, time-varying
signals. The 89600 VSA software analyzes a wide variety of general communications
formats, 2G, 3G, WLAN, WiMAX, UWB, broadband access, and many more.
You can quickly evaluate and troubleshoot digitally modulated signals with both
qualitative displays and quantitative measurements. Then, visualize system
performance rapidly and intuitively with familiar display formats.
Multiple modulation analysis options are available:
Option AYA flexible modulation analysis
Option B7T cdma2000®/1xEV-DV modulation analysis
Option B7U W-CDMA/HSDPA modulation analysis
Option B7W 1xEV-DO modulation analysis
Option B7X TD-SCDMA modulation analysis
Option B7N 3G modulation analysis bundle (an ordering convenience
equivalent to options B7T, B7U, B7W, B7X combined)
Option B7R WLAN modulation analysis
Option B7S IEEE 802.16-2004 OFDM modulation analysis
Option B7Y IEEE 802.16 OFDMA modulation analysis
Option B7Z IEEE 802.11n MIMO modulation analysis
Option BHA TEDS modulation analysis and test
Option BHB MB-OFDM ultra-wideband modulation analysis
Option BHC RFID modulation analysis
The supported modulation formats are listed in the Table 1.
All the error analysis tools described in this section apply to all modulation analysis
options. Specialized modulation formats may have additional tools besides.
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Supported modulation formats
Available with Option AYA
APCO 25 DECT DVB64 HIPERLAN/1 (HBR) TETRA
Bluetooth™ DTV8 DVB128 HIPERLAN/1 (LBR) VDL mode 3
CDMA base DTV16 DVB256 NADC WLAN (802.11b)
CDMA mobile DVB16 EDGE PDC ZigBee (IEEE 802.15.4-2003)
CDPD DVB32 GSM PHP (PHS)
General modulation formats, available with Option AYA
(With variable center frequency, symbol rate, filtering type and alpha/BT)
BPSK, 8PSK VSB 8-, 16- Offset QPSK
QPSK FSK 2-, 4-, 8-, 16-level EDGE
Pi/4 DQPSK DQPSK DVBQAM 16, 32, 64, 128,
256
MSK type 1, type 2 D8PSK APSK 16/32 (12/4QAM)
QAM 16-, 32-, 64-, 128-, 256-, 512-, 1024- π/8 D8PSK
3G Wireless communications formats
cdma2000/1xEV-DV Opt B7T
W-CDMA/HSDPA Opt B7U
1xEV-DO Opt B7W
TD-SCDMA Opt B7X
All of the above Opt B7N
Broadband Wireless Access formats
IEEE 802.16-2004 OFDM Opt B7S
IEEE 802.16 OFDMA Opt B7Y
Wireless Networking formats
WLAN (IEEE 802.11a,b,g,p,j); WLAN (HiperLAN/2) Opt B7R
IEEE 802.11n MIMO (WLAN-HT) Opt B7Z
Public Safety Radio formats
TETRA Enhanced Data Service Opt BHA
Ultra-wideband formats
MB-OFDM Opt BHB
RFID formats Option BHC
EPCGlobal Class-1 Generation-2 UHF (ISO 18000-6 Type-C)
ISO 18000-4 Mode-1
ISO 18000-6 Type A
ISO 18000-6 Type B1
ISO 18092
ISO 14443 Type A
General RFID modulation formats and coding
Forward: DSB-ASK, SSB-ASK, PR-ASK, FSK-2, OOK; None (NRZ); Manchester, FM0, PIE (ISO 18000-6
Type-A), PIE (EPC C1Gen2), Modified Miller
Return: SSB-ASK, BPSK, FSK-2, OOK; None (NRZ); Manchester, FM0, Miller, Miller-2, Miller-4, Miller-8,
Modified Miller, Subcarrier Manchester, Subcarrier BPSK1
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1. Beta
Table 1. Choose from the many available modulation analysis options to meet your measurement
needs. The modulation formats supported by each option are listed above.
Advanced digital demodulators
The 89600 VSA software offers a wide range of digital demodulators. These
advanced technology demodulators do not require external filtering, coherent carrier
signals, or symbol-clock timing signals to successfully demodulate a signal, just
the carrier frequency and symbol rate.
In addition to demodulating your signal, the 89600 digital demodulators use your
signal to generate an ideal reference signal called I/Q reference or FSK reference.
It then compares your measured signal to this ideal reference to quantify and
locate errors in your signal. Built-in filters can be applied to both the measured
and reference signals for maximum flexibility comparing the signals or probing
points in your communication system.
Unique error analysis tools highlight problems
Figure 15. The “v” shape in the EVM versus time display indicates a symbol clock timing error.
Trace math can help determine the approximate clock rate.
Figure 16. This signal shows higher EVM in between the symbols (shown in green) than at
the symbol clock times (shown in red), a clear indication of filtering errors. You can try and
determine the correction needed by using the adaptive equalization filter.
Agilent 89600 VSAs offer sophisticated error analysis that lets you see both RF
and DSP problems. The key is the EVM measurement. The error vector time plots
an error signal versus time diagram. With it, you can identify problems such as
clock timing errors, DAC overflow, compensation errors and more —all with one
screen. Other tools include error vector spectrum and adaptive equalization.
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