Alcatel

Alcatel Lucent

Sonia Rinaldi

Noriaki Kaneda

Silvio Cucchi

Luca Gabriele Razzetti

Stefan Weisser

Paolo Sorge

Gianluca Macheda

Marco Andreasi

Carlo Constantini

Andreas Leven

Stephen Lewis

In a method of demapping a tributary from a first frame into a second frame, the first frame has a plurality of tributary words and a synchronization word, and first and second counters are provided. The first counter is increased by a first value at each dock cycle of the second frame, and reading operations are performed according to the second counter. Synchronization information, generated according to the synchronization word, is used to change between first and second states. When in the first state, the second counter is synchronized to the first counter at each clock cycle of the second frame; and, when in the second state, the second counter is synchronized to the first counter at a predetermined instant of the second frame, the second counter increasing by a second value at each clock cycle of the second frame wherein the reading operation is performed.

Method and device for demapping a tributary recovering lower order synchronism

A method for performing an iterative n-dimensional decoding of a data structure comprising a data bit frame. The method includes receiving possibly errored data; computing syndromes in all the n dimensions in a single step; storing the first calculated syndromes; processing syndromes in a first dimension; correcting errors; and updating the syndromes which have been affected by the correction in the first dimension; and processing syndromes in all the possible dimensions up to the n-th one and, for each of the processed syndromes, correcting errors and updating the syndromes in all the dimensions which have been affected by the correction. The time required by each sub-iteration (from second sub-iteration on) will be progressively reduced. The number of iterations is increased without increasing the delay and processing complexity.

Iterative n-dimensional decoding

Disclosed is a method and erasure FEC decoder for correcting a pattern of errors by a two-dimensional decoding, the pattern of errors comprising at least two codewords in both a first and a second dimensions with a number of errors in common higher than the capacity of the code which is used for decoding. The method comprises the steps of: performing a full capacity decoding along the second dimension for removing possible false corrections introduced by a previous decoding performed along the first dimension; performing a reduced-capacity decoding along the first dimension, for identifying errored codewords along the first dimension; performing a full capacity decoding along the second dimension with disabled correction feature for identifying errored codewords along the second dimension; detecting the error coordinates from the information from steps b) and c); and correcting the detected pattern of errors.

Erasure FEC decoder and method

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Tirano, Italy

Sonia Rinaldi