Correlation – Tektronix AWG610 User Manual

Page 445

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Appendix F: Miscellaneous

AWG610 Arbitrary Waveform Generator User Manual

F-5

Correlation

The operation expressed by the following equation is called correlation. With
respect to a discrete system, correlation y(n) of a certain waveform x(n) and a
second one h(i) is expressed by the following equation. N is the number of items
of data.

yĂ (n) +

ȍ

Nć1

l+0

x(i)h(n ) i)

Periodic. Periodic enables you to specify whether the two-waveforms must be
regarded as periodic during calculation. Below is an example showing differ-
ences between nonperiodic and periodic waveforms.

Waveform A = a0, a1, a2, a3, a4

(5 points)

Waveform B = b0, b1, b2

(3 points)

For nonperiodic case:

<A,B> =

a0b2,

a0b1+a1b2,

a0b0+a1b1+a2b2,
a1b0+a2b1+a3b2,
a2b0+a3b1+a4b2,

a3b0+a4b1,
a4b0,

0,

(8 points)

The data length of the waveform created is the total of the number of points of
the two-waveform files.

For periodic case:

<A,B> =

a0b0+a1b1+a2b2,
a1b0+a2b1+a3b2,
a2b0+a3b1+a4b2,
a3b0+a4b1+a0b2,
a4b0+a0b1+a1b2,

(5 points)

Waveforms A and B are regarded as periodic during calculation. The count of the
operation of the sum of the products is equivalent to the length of the shorter
waveform. The resulting waveform’s cycle equals the same as the longer
waveform. The actually output segment of the waveform corresponds to one
cycle. The starting point value of the waveform equals the sum of products that
is obtained with the starting point values of waveforms A and B added.

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