Method for transmitting a digital signal for a system having at least one dynamic half-duplex relay with selective logic, corresponding program product and relay device

A relaying method in a telecommunication system having a plurality of sources, a half-duplex relay and a recipient. The relay performs a receiving phase of: receiving codewords transmitted by the sources, including estimating for each source a message associated with the codewords transmitted by the source, error detection and decision of error-free decoded messages, which determine the set of sources decoded without error by the relay; a phase of coding and transmitting to the recipient a signal uniquely representative of the selection of messages, such that, after each reception of a block from different sources, the relay receives and decodes a return path from the destination indicating if no or at least one message is decoded without error, these messages determining the set of sources decoded without error. The relay switches from the receiving phase to the coding and transmission phase once a logic rule is valid.