iscatastrophic

True for trellis corresponding to catastrophic convolutional code

Syntax

iscatastrophic(s)

Description

iscatastrophic(s) returns true if the trellis s corresponds to a convolutional code that causes catastrophic error propagation. Otherwise, it returns false.

Examples

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Determine if a Convolutional Code is Catastrophic

This example shows how to determine if a convolutional code causes catastrophic error propagation.

Create the trellis for the standard, rate 1/2, constraint length 7 convolutional code.

t = poly2trellis(7,[171 133]);

Verify that the the code is not catastrophic.

iscatastrophic(t)
ans =

     0

Create a trellis for a different convolutional code using the poly2trellis function.

u = poly2trellis(7,[161 143]);

Verify that the code is catastrophic.

iscatastrophic(u)
ans =

     1

References

[1] Stephen B. Wicker, Error Control Systems for Digital Communication and Storage, Prentice-Hall, 1995, pp. 274-275.

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