# Documentation

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# Binary Symmetric Channel

Introduce binary errors

Channels

## Description

The Binary Symmetric Channel block introduces binary errors to the signal transmitted through this channel.

The input port represents the transmitted binary signal. This block accepts a scalar or vector input signal. The block processes each vector element independently, and introduces an error in a given spot with probability Error probability.

This block uses the DSP System Toolbox™ Random Source block to generate the noise. The block generates random numbers using the Ziggurat method, which is the same method used by the MATLAB® `randn` function. The Initial seed parameter in this block initializes the noise generator. Initial seed can be either a scalar or a vector, with a length that matches the number of channels in the input signal. For details on Initial seed, see the Random Source block reference page in the DSP System Toolbox documentation set.

The first output port is the binary signal the channel processes. The second output port is the vector of errors the block introduces. To suppress the second output port, clear Output error vector.

## Parameters

Error probability

The probability that a binary error occurs. Set the value of this parameter between `0` and `1`.

Initial seed

The initial seed value for the random number generator.

Output error vector

When you select this box the block outputs the vector of errors.

Output data type

Select the output data type as double or boolean.

## Examples

An example using the Binary Symmetric Channel block is in the section Design a Rate 2/3 Feedforward Encoder Using Simulink.

## Supported Data Types

PortSupported Data Types

Input

• Double-precision floating point

• Single-precision floating point

• Fixed point (signed and unsigned)

• Boolean

• 8-, 16-, and 32-bit signed integers

• 8-, 16-, and 32-bit unsigned integers

Output

• Double-precision floating point

• Boolean