Method and device for convolutive encoding and transmission by packets of a digital data series flow, and corresponding decoding method and device

A method for decoding a digital data series flow encoded by convolutive encoding using a stable starting binary value and transmitted by packets, said method comprising the following steps:

• a) receiving a packet of encoded symbols S(k) and an encapsulation message;
• b) discriminating said encapsulation message in order to generate an envelope logic signal having a first binary value prior to the start, and subsequently at the end, of said packet of encoded symbols and a second binary value during the reception of said packet of encoded symbols;
• c) subjecting said envelope logic signal and said encoded symbols to a logic processing enabling to generate:
• successive pause symbols of specified value and rank, on the basis of said stable starting binary value of the received packet, for said first binary value of said envelope logic signal, and
• successive validated encoded symbols S′k={a′(k);b′(k)} of rank k corresponding to said symbols S(k) for said second binary value of said envelope logic signal;
• and
• subjecting said successive validated pause symbols and validated encoded symbols of given rank to a continuous VITERBI type decoding, said pause symbols enabling the continuity of the decoding lattice to be obtained by imposing a stable state between two packets of successive encoded symbols.

A decoding device for a series flow of digital data encoded by convolutive encoding using a stable starting binary value and transmitted by packets comprising:

• means for receiving a packet of encoded symbols S(k) and an encapsulation message;
• discriminating means of said encapsulation message enabling an envelope logic signal to be generated for said current packet, said envelope logic signal having a first logic value before the beginning and after the end of the encoded symbol packet and a second logic value during the receiving of the packet;
• logic processing means for generating:
• successive pause symbols of specified value and rank, on the basis of said stable starting binary value of the received packet, for said first binary value of said envelope logic signal, and
• successive validated encoded symbols S′k={a′(k);
• b′(k)} of rank k corresponding to said symbols S(k) for said second binary value of said envelope logic signal;
• and
• VITERBI decoding means for carrying out, on the basis of said pause symbols and validated encoded symbols of given rank, a continuous VITERBI type decoding, said pause symbols enabling the continuity of the decoding lattice to be obtained by imposing a stable state between two packets of successive encoded symbols.

A method for convolutive encoding and transmission by packets of a digital data series flow which is formed by successive number of bits i(k) of specified value, through a convolutive encoding of depth K, said method comprising the following steps:

• a) discriminating in said series flow a set of successive bits, in order to form a current packet;
• b) defining for said convolutive encoding a stable starting binary value;
• c) subjecting said digital data i(k) of the current packet to a convolutive encoding process, at each value of bit i( )k) corresponding to a first a(k) and a second b(k) encoded value, the set of these first and second encoded values constituting an encoded symbol S(k)={a(k);b(k)} representative of the considered bit i(k);
• d) forming, from the encoded symbols, a packet of encoded symbols by concatenation of said encoded symbols;
• e) assigning to said convolutive encoding process said aforementioned stable value as a constraint value at the end of said packet;
• f) generating at least one encapsulation message of said packet of encoded symbols, said message comprising a packet length field;
• g) transmitting, in the same message, said encapsulation message and said packet of encoded symbols for decoding and use;
• and
• h) repeating the operations a) to g) for each current packet constituting said flow of bits.

A method for decoding a digital data series flow encoded by convolutive encoding using a stable starting binary value and transmitted by packets, comprising the following steps:

• a) receiving a packet of encoded symbols S(k) and an encapsulation message comprising a field indicating the length of said packet;
• b) discriminating said encapsulation message in order to generate, on the basis of the packet length, an envelope logic signal having a first binary value prior to the start and subsequently at the end of said packet of encoded symbols and a second binary value during the reception of said packet of encoded symbols;
• c) subjecting said envelope logic signal and said encoded symbols to a logic processing enabling to generate:
• successive pause symbols of specified value and rank, on the basis of said stable starting binary value, for said first binary value of said envelope logic signal, and
• successive validated encoded symbols S′k={a′(k);b′(k)} of rank k corresponding to said symbols S(k) for said second binary value of said envelope logic signal;
• and
• d) subjecting said successive validated pause symbols and validated encoded symbols of given rank to a continuous VITERBI type decoding, said pause symbols enabling the continuity of the decoding lattice to be obtained by imposing a stable state between two packets of successive encoded symbols.

A decoding device for a series flow of digital data encoded by convolutive encoding using a stable starting binary value and transmitted by packets, said device comprising:

• means for receiving a packet of encoded symbols S(k) and an encapsulation message comprising a field indicating the length of the packet;
• discriminating means for said encapsulation message for enabling an envelope logic signal to be generated for said current packet, on the basis of the packet length, said envelope logic signal having a first logic value before the beginning and after the end of the encoded symbol packet and a second logic value during the receiving of the packet;
• logic processing means for generating:
• successive pause symbols of specified value and rank, on the basis of said stable starting binary value, for said first binary value of said envelope logic signal, and
• successive validated encoded symbols S′k={a′(k);
• b′(k)} of rank k corresponding to said symbols S(k) for said second binary value of said envelope logic signal;
• and
• VITERBI decoding means for carrying out, on the basis of said pause symbols and validated encoded symbols of given rank, a continuous VITERBI type decoding, said pause symbols enabling the continuity of the decoding lattice to be obtained by imposing a stable state between two packets of successive encoded symbols.