Descramble input signal
The Descrambler block descrambles a scalar or column vector input signal. The Descrambler block is the inverse of the Scrambler block. If you use the Scrambler block in a transmitter, then you use the Descrambler block in the related receiver.
In the following descrambler schematic, the adders and subtracter operate modulo N, where N is the Calculation base parameter. You must specify integer input values between 0 and N-1.
At each time step, the input causes the contents of the registers to shift sequentially. Using the Scramble polynomial parameter, you specify if each switch in the descrambler is on or off. To make the Descrambler block reverse the operation of the Scrambler block, use the same Scramble polynomial parameters in both blocks. If there is no signal delay between the scrambler and the descrambler, then the Initial states in the two blocks must be the same. See the reference page for the Scrambler block for more information about these parameters. There is an optional port that can be used to reset the descrambler.
Alternatively, the initial states can be provided by an input
port when Initial states source parameter is
This block can accept input sequences that vary in length during simulation. For more information about sequences that vary in length, or variable-size signals, see Variable-Size Signal Basics (Simulink) in the Simulink® documentation.
The calculation base N. The input and output of this block are integers in the range [0, N-1].
A polynomial that defines the connections in the scrambler.
A drop down menu that controls the source of the initial states.
Dialog Parameter or
port. The default value is
The states of the descrambler's registers when the simulation
starts. This parameter is available when Initial states
source is set to
A check box that creates a reset port. When checked, the descrambler
is reset if a nonzero input is applied to the port. This control is
available when Initial states source is set to
Parameter. The default is that the box is not checked.