Patents Assigned to Alcatel Transmission Par Faisceaux Hertziens A.T.F.H.
  • Method of automatically requesting retransmission in a duplex digital transmission system having at least one noisy return channel, and an installation for implementing the method
    Patent number: 5483545
    Abstract: A go-back-N automatic repeat request method for use on a duplex installation having noisy return channels. When an acknowledge signal (ACK) is not correctly received, it is assumed to be positive until the Nth successive incorrectly received acknowledgement, which is treated as a negative acknowledgement, thereby ensuring that blocks are repeated even if acknowledgements are degraded by jamming.
    Type: Grant
    Filed: September 18, 1992
    Date of Patent: January 9, 1996
    Assignee: Alcatel Transmission Par Faisceaux Hertziens A.T.F.H.
    Inventors: Marc Darmon, Marc Pontif, Philippe Sadot
  • Method and apparatus for sequentially decoding a digital stream encoded by a convolution type error-correcting code
    Patent number: 5329536
    Abstract: A method and apparatus for sequential decoding using the stack algorithm. A stack is used which is small in size and which has a leaky bottom. A counter stores the total count of nodes observed so as to abandon decoding if this count exceeds a fixed value. A comparator continuously compares the metric at the top of the stack with the largest metric lost from the bottom of the stack as stored in a memory. A small memory stores the path scanned through the logic tree, thereby directly providing the decoded block.
    Type: Grant
    Filed: March 28, 1991
    Date of Patent: July 12, 1994
    Assignee: Alcatel Transmission par Faisceaux Hertziens A.T.F.H.
    Inventors: Marc Darmon, Andre Bazet, Pascal Brelivet
  • Method and apparatus for digital data transmission with automatic repeat request
    Patent number: 5313473
    Abstract: Enough room is provided in a transmitted frame to receive a plurality (n) of useful information blocks, thereby making it possible to catch up any excessive lateness (r) which may arise due to successive repeats. The decoder (2) provides a confidence flag (3) to the controlling microprocessor (5). The command block (COM) from the decoder includes an indication of the number of useful blocks that are transmitted in the frame. This block is advantageously applied to an HDLC component (8).
    Type: Grant
    Filed: September 8, 1992
    Date of Patent: May 17, 1994
    Assignee: Alcatel Transmission Par Faisceaux Hertziens A.T.F.H.
    Inventors: Marc Darmon, Marc Pontif, Philippe Sadot