2-22
IM 704510-01E
Statistical Calculation Parameters
In the following equations, n is the number of samples, X
i
is the measured value of each
sample, and X
j
(only for histograms) is the median value of each bin of the histogram.
If the statistics are calculated on the time variation, “T.” is placed in front of the statistical
calculation parameter names.
• Average
Calculates the average value of the measured values.
Average =
X
i
1
n
Σ
n
i=1
• Maximum
Indicates the maximum measured value.
Maximum = [X
i
]
max
• Minimum
Indicates the minimum measured value.
Minimum = [X
i
]
min
• Peak-Peak
Calculates the difference between the maximum and minimum values.
Peak – Peak = Maximum – Minimum
• Standard deviation (
σ
)
Calculates the standard deviation of the measured values. This indicates the degree
to which the values are spread out from the average value.
σ
=
(X
i
– Average)
2
1
n
Σ
n
i=1
• Flutter (
σ
/Average)
Calculates the flutter. This indicates the spread in the values in terms of a percentage
of the average value.
σ
/Average =
×
100 (%)
σ
Average
•
σ
/T (only for histograms)
Calculates the histogram jitter using the specified constant T. Indicates the spread of
the values in terms of a percentage of the value T.
σ
/T =
×
100 (%)
σ
T
• Deviation (only for histograms)
X
CENTER
is the center value of the x axis in the window (see page 2-13).
Indicates the deviation of the measured average value with respect to X
CENTER
.
Deviation = Average – X
CENTER
• Deviation/T (only for histograms)
Indicates the deviation of the measured average value with respect to X
CENTER
in
terms of a percentage of the value T.
Deviation/T =
×
100 (%)
|Average – X
CENTER
|
T
• Median (only for histograms)
Indicates the median of the histogram.
Median = [X
j
]
Median
• Mode (only for histograms)
Indicates the median value with the highest frequency of occurrence (most frequent value).
Mode = [X
j
]
Mode
2.7 Statistical Calculation and Inter-Symbol Interference Analysis