Data block convolutional coding device and method, and corresponding decoding method and device

A device for the convolutive encoding of blocks each formed by a predetermined number N of source data elements,

• comprising means for the introducing of each of said source data elements twice into one and the same convolutive encoder implementing a generating polynomial with a period L in an order such that the two instances of introduction of one and same source data element d.sub.i are separated by the introduction of (p.sub.i.L)-1 other source data elements, p.sub.i being a non-zero integer.

A method for the decoding of an encoded block formed by encoded data, corresponding to a source block formed by a predetermined number N of source data elements,

• wherein said block has undergone an encoding such that each of said source data elements is introduced twice into one and the same convolutive encoder implementing a generating polynomial with a period L in an order such that the two instances of introduction of one and same source data element d.sub.i are separated by the introduction of (p.sub.i.L)-1 other source data elements, p.sub.i being a non-zero integer,
• and wherein the method comprises a maximum likelihood decoding step taking account, firstly, of the received encoded data elements and, secondly, of the fact that the initial state and the final state of the encoder are known.

A decoder of an encoded block formed by encoded data elements corresponding to a source block formed by a predetermined number N of source data elements,

• wherein said source block has undergone an encoding such that each of said source data elements is introduced twice into one and the same convolutive encoder implementing a generating polynomial with a period L in an order such that the two instances of introduction of one and same source data element d.sub.i are separated by the introduction of (p.sub.i.L)-1 other source data elements, p.sub.i being a non-zero integer,
• and wherein said decoder comprises maximum likelihood decoding means taking account, firstly, of the encoded data elements received and, secondly, of the fact that the initial state and the final state of the encoder are known.