- Supports all transmitter compliance measurements for WiMedia and Certified Wireless USB
- The only UWB analysis package tightly integrated with the oscilloscope software
- Easy to learn and remember
- Automated compliance testing and report generation
- Power Spectral Density plots and mask test
- Flexible Spectrogram analysis
- Modulation analysis
- Multi-band Orthogonal Frequency Division Multiplexing with QPSK and DCM subcarrier modulation
- Constellation display
- I & Q vs. time display
- Magnitude/Phase vs. tone display (symbol by symbol)
- Automated measurements of:
- Frequency Error
- Preamble Cross Correlation
- Power deviation relative to Preamble Sync of CE, Header and Payload
- Band power and total power
- Error Vector Magnitude (EVM)
- Adjacent Channel Power Ratio (ACPR)
- Common Phase Error (CPE) vs. Time Plots
QPHY-UWB – Powerful Tool
The QPHY-UWB software package for the Serial Data Analyzer family provides a concise set of validation/verification and debug tools written in accordance with the WiMedia PHY Compliance and Interoperability Test Specification.
The Teledyne LeCroy SDA 13000 or SDA 11000 Serial Data Analyzers provide the ideal combination of high bandwidth, high sample rate, and deep capture memory to enable the user to capture the entire UWB spectrum. Covered transmission test features include Power Spectral Density (PSD) mask testing of the bands in use in any band group (1-6), constellation display, and Error Vector Magnitude (EVM) measurement of UWB radio signals.
Teledyne LeCroy's QPHY-UWB package includes capabilities beyond the requirements of the WiMedia PHY Compliance and Inter operability Test Specification which are useful for troubleshooting problems in MB-OFDM UWB signals.
Simple and Complete
The QPHY-UWB package enables transmitter measurements on direct RF signal output and is the only commercially available software package that combines EVM Measurement, PSD, and Constellations diagrams into a single application which is totally integrated into the oscilloscope. Other UWB analysis packages run as applications in external math processing software, which compromises the speed and the ability to operate the option software in the same manner as the oscilloscope.
The 6 main Analysis buttons on the main menu allow the user to access the 6 analysis views:
- PSD (Mask and ACPR)
- CPE vs. Time
The QPHY-UWB spectrogram display provides a truly intuitive view of how the UWB signal frequency content evolves over time. The spectrogram is a 3-D plot where the power is shown color-graded as a function of frequency on the vertical axis and time on the horizontal axis. The time axis of the spectrogram is locked to the time axis of the input signal, so as you zoom in and out on the input, the spectrogram time axis will follow automatically. The center frequency and span are automatically set to optimally show the band group in use, and in addition can be independently controlled.
Spectrogram View – TFC1 signal hopping over 3 three bands.
This view provides a display of the constellation as well as the majority of the parameters needed to estimate the signal quality. This analysis can be done over all data and pilot tones, only data or pilot tones, or on a selected single symbol or selected single tone. This ability allows the user to narrow in on possible explanations for poor EVM. The measurement parameters displayed in this view are:
- EVM – Error Vector Magnitude
- FrqErr – Frequency Error
- SCorr – Sync Cross correlation
- pCE – CE power relative to sync
- pHDR – Header power relative to sync
- pPSDU – Payload power relative to sync
To the left of the constellation plot is a time-based display of the complex FFT I and Q samples from each symbol plotted in subcarrier order with successive symbols in time order. The I and Q subcarrier samples within a symbol are spread over a time equal to the symbol duration. In the data shown here, it is readily seen that something disturbed the carrier phase at the beginning of the packet degrading the constellation quality and EVM.
EVM/Constellation view – 53 Mbps rate – QPSK.
Magnitude and Phase View
The magnitude and phase view of the spectrum of a user specified symbol allows checking for variations of phase or magnitude of any tone from symbol to symbol. In this display the CE symbols are not equalized, providing a view of what the signal really looks like before equalization. Header and payload symbols are equalized. In the display shown, the magnitude is plotted on the upper grid at 3 dB/division, and the phase is plotted on the lower grid at 45 degrees/division. The magnitude and phase points from each tone are plotted from -61 on the left to +61 on the right. Cursors can be turned on to read out values on any individual tone.
Magnitude and Phase View – Symbol 25, a CE symbol.
Common Phase Error View
The WiMedia test specification requires that the common phase error (CPE) correction applied to each symbol is a low pass filtered value with a time constant on the order of 12 symbols duration. This results in a residual CPE, in most cases due to phase noise above the passband of this filter, which can deteriorate EVM. QPHY-UWB provides plots of the common phase error versus time for understanding the magnitude of any phase noise problem and its dependence on time. In the display shown, the CPE is being displayed at 2 degrees per vertical division. The horizontal time scale of the CPE plot is locked to the scale of the input waveform trace.
Common Phase Error (CPE) versus time for each band.
Test with QualiPHY
QPHY-UWB works with the Teledyne LeCroy QualiPHY compliance test automation tool. QualiPHY automates setup of the scope when running a sequence of tests, stores the data in a database, and prints a test report with all the measurement results, including displays. A QualiPHY test sequence for implementing the full WiMedia Compliance test suite is included with QPHY-UWB. Variations or subsets of this test sequence can easily be created by copying the pro vided sequence and changing its configuration. To the left are shown the main control panel for QualiPHY and an example of the 1st page of a test report. QualiPHY is available for download on the Teledyne LeCroy website.
WiMedia Defined Test Measurements:
- Frequency Tolerance
- Normalized cross correlation for preamble symbols
- Power of CE sequence relative to preamble sync sequence
- Power of header relative to preamble sync sequence
- Power of payload relative to preamble sync sequence
- Spectral Mask Test
- Adjacent Channel Power Ratio (ACPR) Test
- EVM test
- TFC 1 through TFC 10. Band groups 1 through 6.
- Spectrogram display
- EVM & constellation by symbol and by tone
- Phase & Magnitude vs. Frequency display of symbol
- CPE vs. time display
- Band power and total power to aid in TPC testing Automation of test measurements, storage of data, and test report generation with QualiPHY