ZigBee Low Rate PHY Signal Analysis Solution

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Features

Supported frequency range

• 2.4 GHz band

Measurements
RF Measurements

• Power spectral Density
• Occupied bandwidth
• Power in Upper and Lower Bands
• Power in band (total power)

Baseband Measurements

• IQ Plots
• I plot
• IQ plot
• IQ Phase Plot
• IQ Magnitude plot
• Error Vector Magnitude (EVM)
• Constellation
• Eye Diagram
• CCDF
• Data bits

Extensive Graphical capabilities

• Changing plot color
• Thickness and style of lines
• Zoom
• Markers
• Auto Scale for better viewing of PSD and CCDF curve

Configurations

• Configure Digitizer device
• Configure Downconverter device
• Span
• Trigger level

Display Parameters

• Frequency Offset
• Frame Length

Extensive Graphical capabilities

• Changing plot color
• Thickness and style of lines
• Zoom
• Markers
• Auto Scale for better viewing of PSD and CCDF curve
• Indicates Preamble Detection
• Indicates Packet Detection
• Indicates SFD detection

Comprehensive Help

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Setup

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Measurements

RF Measurements

Power Spectral Density (PSD)
Power spectral density (PSD) describes how the power of a time series is distributed with frequency. This measurement is used to check a measured PSD against the spectral mask requirement specified in the IEEE 802.15.4 standard. The PSD mask helps to check whether the measured spectrum is within standard limits (Absolute and Relative).

Power in Band
WiPAN LVSA calculates the integrated power (dBm) in the specified channel or band.

Occupied bandwidth
Occupied Bandwidth returns the bandwidth of the specified frequency band that contains 99% percent of the total power of the span.

Adjacent Channel Power
Adjacent Channel Power measurement comprises of Power in the upper and lower bands. According to IEEE 802.15.4, upper band is 5MHz towards the right of the operating frequency and the lower band is 5MHz towards the left of the operating frequency.

Baseband Measurements

IQ Time Domain
WiPAN LVSA provides the following IQ measurements 

1. I Plot- Only I data is plotted
2. IQ Plot- combined IQ Plot
3. Phase Plot- provides a view of the phase linearity of the acquired data.
4. Magnitude plot - provides for a better view of the power level of the signal

IQ Plot

Constellation
The Constellation display provides a graphic representation of the modulated signal. The size and shape of the constellation indicates the type of impairment added to the signal. The constellation diagram is displayed after half-sine pulse shaping has been applied.

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Eye Diagram
The eye diagram reveals the modulation characteristics of the signal, such as pulse shaping or channel distortions. Using this measurement, designers can decide on the optimum sampling point / decision for decoding the data. During analysis, the user can check for the maximum Eye openings in the signal after offset removal (OQPSK -> QPSK) to validate good demodulation properties.

Data bits
The decoded raw data is a presented as a stream of 1s and 0s, useful for calculating the BER (Bit Error Rate) measurement. During Analysis, the user can check for the decoded data bits with transmitted reference data bits without any impairment added to validate zero BER.

CCDF
Complementary Cumulative Distribution Function (CCDF) is used to analyze the power characteristics of a signal. CCDF curves help power amplifier designers know exactly how stressful a signal the amplifier will need to handle. A relatively flat profile ensures your Power Amplifier is not driven to saturation

Error Vector Magnitude (EVM)
EVM enables you to capture various problems and impairments, such as LO (Local Oscillator) stability, IF filter, compression, symbol rate and interfering tones. By measuring EVM, the linearity and efficiency can be verified. During analysis, the user can check whether EVM always falls below the standard-specified reference of 0.35 which ensures good demodulation of the transmitted signals.

Data Bits


CCDF Plot


EVM


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System Requirements

• System Memory: Minimum 512 MB, recommended 1GB
• Disk Space: 100 MB
• OS: Windows 2000/XP
• NI-PXI 5660 RF Signal Analyzer
• NI PXI 5600 (Downconvertor)
• NI PXI 5620 (Digitizer)
• Driver : NI PXI 5660 RFSA Ver 1.5
• LabVIEW Runtime Engine 7.1

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