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Scramble input signal

The Scrambler block scrambles a scalar or column vector input
signal. If you set the **Calculation base** parameter
to *N*, then the input values must be integers between
0 and N-1.

One purpose of scrambling is to reduce the length of strings
of 0s or 1s in a transmitted signal, since a long string of 0s or
1s may cause transmission synchronization problems. Below is a schematic
of the scrambler. All adders perform addition modulo *N*.

At each time step, the input causes the contents of the registers
to shift sequentially. The **Scramble polynomial** parameter
defines if each switch in the scrambler is on or off. Specify the
polynomial by listing its coefficients in order of ascending powers
of *z*^{-1}, where *p*(*z*^{-1})
= 1 + *p _{1}z*

The **Initial states** parameter lists the
states of the scrambler's registers when the simulation starts. The
elements of this vector must be integers between 0 and *N*-1.
The vector length of this parameter must equal the order of the scramble
polynomial. (If the **Scramble polynomial** parameter
is a vector that lists the coefficients in order, then the order of
the scramble polynomial is one less than the vector length.)

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