Decode binary lowdensity paritycheck (LDPC) code
Communications Toolbox / Error Detection and Correction / Block
The LDPC Decoder block uses the belief propagation algorithm to decode a binary LDPC code, which is input to the block as the softdecision output (loglikelihood ratio of received bits) from demodulation. The block decodes generic binary LDPC codes where no patterns in the paritycheck matrix are assumed. For more information, see Belief Propagation Decoding.
The input and output are discretetime signals. The ratio of the output sample time to the input sample time is:
N/K when only the informationpart of the codeword is decoded
1 when the entire codeword is decoded
N is the length of the received signal and must be in the range (0, 2^{31}). K is the length of the uncoded message and must be less than N.
This icon shows all ports, including optional ports, for the LDPC Decoder block.
Data Types 

Multidimensional Signals 

VariableSize Signals 

[1] Gallager, Robert G. LowDensity ParityCheck Codes. Cambridge, MA: MIT Press, 1963.