Encoder, decoder and encoding method with low error floor

An encoder for encoding digital data, said encoder comprising

• one or more component encoders, each component encoder being a systematic block encoder suitable for encoding a local information word such as to generate a local code word including the local information word and a number of parity bits,
• one or more interconnections, said interconnections connecting different ones of said component encoders or connecting a component encoder with itself,
• one or more inputs for inputting external digital information to corresponding one or more of the component encoders, and
• one or more outputs for outputting encoded digital data from at least a subset of the component encoders,
• wherein the encoder is configured to carry out a sequence of processing steps, each processing step comprising the following steps:
• combining, at least a subset of said component encoders, internal input bits received via a corresponding one of said interconnections and external input bits received via the corresponding input, if present, to assemble a local information word,
• encoding the local information word such as to generate a local code word including the local information and a number of parity bits, and
• outputting, from at least some of said component encoders, a reduced local code word via the corresponding output, and handing the same reduced local code word over to a corresponding one of said interconnections for forwarding said same reduced local code word via said interconnection to another component encoder or to itself, wherein said reduced local code word corresponds to the parity bits and the external input bits, but not the internal input bits received via the interconnection,
• wherein said encoder is configured to forward on each interconnection bits of the reduced local code word in parallel but with delays that are mutually different for at least a subset of the reduced local code word bits,
• wherein a number of component encoders is one, or
• wherein a number of component encoders is two or more, of which at least one component encoder does not have an input for inputting external digital information.