Table Of Contents

MT Measure Burst Timing (G Dataflow)

Last Modified: January 9, 2017

Locates a burst within the input complex waveform with peaks correlating to the input ideal power curve.

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Note  

The upper mask, ideal power curve, and lower mask arrays must contain the same number of elements.

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input complex waveform

The time-aligned and oversampled complex waveform data after matched filtering and frequency offset correction.

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t0

Trigger (start) time of the Y array.

Default: 0.0

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dt

Time interval between data points in the Y array.

Default: 1.0

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Y

The complex-valued signal-only baseband modulated waveform. The real and imaginary parts of this complex data array correspond to the in-phase (I) and quadrature-phase (Q) data, respectively.

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upper mask

The upper mask threshold for burst power in dB.

Default: 0

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ideal power curve

The best location for the power curve.

This curve is correlated against the input complex waveform to find the peak correlation. The ideal power curve must always be located between the upper mask and the lower mask.

Default: 0

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lower mask

The lower mask threshold for burst power in dB.

Default: 0

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error in

Error conditions that occur before this node runs. The node responds to this input according to standard error behavior.

Default: no error

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impairment measurement window

The portion of the input complex waveform that is measured for amplitude droop and crest factor. This cluster is specified relative to the start of the region delineated by the upper mask, ideal power curve, and lower mask parameters.

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start index

Index of the first sample of the measurement window.

Default: 0

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width

Number of samples over which amplitude droop and crest factor are measured. This value must be 2 or greater.

Default: 100

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amplitude droop

The amplitude droop, in dB, calculated over the specified impairment measurement window.

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pass?

A Boolean that determines whether the peak-correlated portion of the input complex waveform meets the upper mask and lower mask specifications.

TRUE Indicates that all samples fall within the region defined by the upper mask and lower mask parameters.
FALSE Indicates that all samples do not fall within the region defined by the upper mask and lower mask parameters.
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first error sample index

The index value of the first sample in the peak-correlated portion of the input complex waveform that falls outside of the region defined by the upper mask and lower mask parameters. This index value is an offset into the upper mask/lower mask arrays.

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correlated burst index

Index value of the first sample in the peak-correlated portion of the input complex waveform, in samples. This index value is relative to the start of the input complex waveform.

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crest factor

The measured crest factor of the power envelope calculated over the specified impairment measurement window.

The calculation is defined as the dimensionless quantity [ 10 × log ( M a x p n / M e a n p n ]

where p n is the power envelope of the input complex waveform.

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error out

Error information. The node produces this output according to standard error behavior.

Burst Timing

For burst signals, burst timing refers to the location of the burst obtained by its correlation against an ideal power curve. In addition, an upper and lower mask are used to test whether the burst signal satisfies mask specifications. The following figure illustrates the ideal power curve, upper mask, and lower mask.

This node compares the peak-correlated section with the upper mask and lower mask parameters to validate that the peak-correlated portion falls within the mask specification. Finally, the node measures and returns the amplitude droop and crest factor of the peak-correlated portion of the input complex waveform.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported


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