MT Measure Burst Timing
- Updated2023-02-17
- 4 minute(s) read
MT Measure Burst Timing
Locates a burst within the input complex waveform with peaks correlating to the input ideal power curve.
Inputs/Outputs
input complex waveform
The time-aligned and oversampled complex waveform data after matched filtering and frequency offset correction.
t0
Trigger (start) time of the Y array.
Default value: 0.0
dt
Time interval between data points in the Y array.
Default value: 1.0
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.
upper mask
The upper mask threshold for burst power in dB.
Default value: 0
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 value: 0
lower mask
The lower mask threshold for burst power in dB.
Default value: 0
error in
Error conditions that occur before this node runs.
The node responds to this input according to standard error behavior.
Default value: No error
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.
start index
Index of the first sample of the measurement window.
Default value: 0
width
Number of samples over which amplitude droop and crest factor are measured. This value must be 2 or greater.
Default value: 100
amplitude droop
The amplitude droop, in dB, calculated over the specified impairment measurement window.
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. |
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.
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.
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
where is the power envelope of the input complex waveform.
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.