Decode binary low-density parity-check (LDPC) code

The `comm.LDPCDecoder`

System
object™ uses the belief propagation algorithm to decode a binary LDPC code, which is
input to the object as the soft-decision output (log-likelihood ratio of received bits) from
demodulation. The object decodes generic binary LDPC codes where no patterns in the
parity-check matrix are assumed. For more information, see Belief Propagation Decoding.

To decode an LDPC-encoded signal:

Create the

`comm.LDPCDecoder`

object and set its properties.Call the object with arguments, as if it were a function.

To learn more about how System objects work, see What Are System Objects? (MATLAB).

creates a
binary LDPC decoder System
object. This object performs LDPC decoding based on the specified parity-check
matrix.`ldpcdecoder`

= comm.LDPCDecoder

sets the `ldpcdecoder`

= comm.LDPCDecoder(`parity`

)`ParityCheckMatrix`

property to `parity`

and
creates an LDPC decoder System
object. The `parity`

input must be specified as described by the
`ParityCheckMatrix`

property.

sets properties using one or more name-value pairs, in addition to inputs from any of the
prior syntaxes. For example, `ldpcdecoder`

= comm.LDPCDecoder(___,`Name`

,`Value`

)```
comm.LDPCDecoder('DecisionMethod','Soft
decision')
```

configures an LDPC decoder System
object to decode data using the soft-decision method and output log-likelihood
ratios of data type `double`

. Enclose each property name in
quotes.

To use an object function, specify the
System
object as the first input argument. For
example, to release system resources of a System
object named `obj`

, use
this syntax:

release(obj)

[1] Gallager, Robert G. *Low-Density Parity-Check Codes*. Cambridge, MA: MIT Press,
1963.