Abstract: A decoder of LDPC codewords using the iterative belief propagation algorithm stores a posteriori information on variables. An updating device updates the a posteriori information on variables, and a first computation device computes variables to constrain messages from a posteriori information on variables and variable to constraint messages from previous iteration. A second computation device computes a constraint to variable messages from variable to constraint messages computed by the first computation device. A further computation device updates the a posteriori information on variables. A shuffle device transfers the a posteriori information on variables to the first computation device, and a further shuffle device transfers information from the second computation device to the storing device. The decoder further includes a device for compression-storage-decompression of the constraint to variable messages. The disclosure also relates to a corresponding method, computer program and system.

Abstract: A decoder of LDPC codewords on GF(rq), using the iterative belief propagation algorithm comprises at least storing means to store a posteriori information on variables. Updating means updates the a posteriori information on variables, and computation means computes variables to constrain messages from a posteriori information on variables and variable to constraint messages from previous iteration. Computation means computes a constraint to variable messages from variable to constraint messages computed by the first computation means. Computation means updates the a posteriori information on variables. Shuffle means transfers the a posteriori information on variables to the first computation means, and shuffle means transfers information from the second computation means to the storing means. Compression-storage-decompression means constraint to variable messages. In one form, the invention concerns also corresponding method, computer program and system.