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Scramble input signal

**Library:**Communications System Toolbox / Sequence Operations

The Scrambler block scrambles a scalar or column vector input signal.

One purpose of scrambling is to reduce the length of consecutive 0s or 1s in a
transmitted signal. Long sequences of 0s or 1s can cause transmission synchronization
problems. This schematic shows the scrambler operation. All adders perform addition
modulo *N*, where *N* is the value specified by the
Calculation base
parameter.

At each time step, the input causes the contents of the registers to shift sequentially. Using the Scramble polynomial parameter, you specify the on or off state for each switch in the scrambler.

To achieve repeatable initial scrambler conditions, you can use one of these optional input ports:

Select the Reset on nonzero input via port parameter and reset the scrambler with Rst.

Set the Initial states source parameter to

`Input port`

and provide the initial states with ISt.

This block can accept input sequences that vary in length during simulation. For more information about sequences that vary in length, see Variable-Size Signal Basics (Simulink).

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