Relaying method and device and destination with feedback in an OMAMRC system
A method for relaying messages via a half-duplex relay for a telecommunications system with M sources, L relays and a destination, where M>1, L≥1, according to an orthogonal multiple access scheme of the transmission channel between the L relays and the destination. The method includes: decoding, via a relay, M messages each being associated with a frame and coming from a source among the M sources with detection of errors on the messages; transmitting from the relay to the destination a signal representative of a least one portion of a set of the messages for which no errors have been detected by the relay conditional on authorization from the destination, transmitting from the relay to the destination of a monitoring signal indicating a set of messages for which no errors have been detected by this relay, this transmission of the monitoring signal occurring before the transmission of the representative signal.
1. A method of relaying messages by a half-duplex relay for a telecommunication system with M sources, at least one half-duplex relay and a destination, M>1, according to a scheme for orthogonal multiple access of the transmission channel between the at least one half-duplex relay and the destination, comprising the following acts:
decoding by the at least one half-duplex relay M messages each associated with a frame and originating from a source from among the M sources with detection of errors in the decoded messages,
transmitting from the at least one half-duplex relay to the destination a control signal carrying only control information indicating a set of decoded messages for which no error has been detected by this half-duplex relay,
after transmitting the control signal and receiving a feedback control signal from the destination in response to the transmitted control signal, transmitting from the at least one half-duplex relay to the destination a signal representative of at least one part of the set of those decoded messages for which no error has been detected by the at least one half-duplex relay solely under condition of an authorization originating from the destination given by way of the feedback control signal.
2. The method of relaying as claimed in claim 1 in which the orthogonal multiple access scheme divides the access to the channel into two phases, a first phase of M time slots corresponding to the transmission of the M messages by the M sources, a second phase of variable length corresponding to the conditional transmissions of the at least one half-duplex relay.
3. The method of relaying as claimed in claim 1 in which the authorization originating from the destination comprises an identification of a selected node authorized to transmit.
4. The method of relaying as claimed in claim 1 in which the authorization originating from the destination furthermore comprises an indication of a set of decoded messages for which no error has been detected to be selected by the at least one half-duplex relay to generate the representative signal.
5. The method of relaying as claimed in claim 3 in which the authorization originating from the destination is given by way of nominative feedback control signals indicating decoding without detected error or otherwise of each of the M messages and in which the representative signal transmitted is generated on the basis of a set of messages updated on the basis of the nominative feedback control signals received.
6. The method of relaying as claimed in claim 5 in which the at least one half-duplex relay transmits the set non-updated on the basis of the nominative feedback control signals received.
7. The method of relaying as claimed in claim 5 in which the at least one half-duplex relay transmits the set updated on the basis of the nominative feedback control signals received.
8. The method of relaying as claimed in claim 2 , in which the second phase comprises conditional transmissions of the sources under condition of an authorization originating from the destination.
9. The method of relaying as claimed in claim 1 in which the at least one half-duplex relay decodes M other messages originating respectively from the M sources and each associated with another frame immediately upon receipt of a feedback control signal originating from the destination indicating decoding of the M messages without detection of error.
10. A half-duplex relay for a telecommunication system with M sources, at least the half-duplex relay and a destination, access to the transmission channel between the half-duplex relay and the destination following an orthogonal multiple access scheme, the half-duplex relay comprising:
a decoder of M messages transmitted by the M sources which obtains decoded messages and detects errors in the decoded messages,
a network coder which generates a signal representative of at least one part of a set of the decoded messages for which no error has been detected,
a transmitter,
a controller of the transmitter configured to:
transmit a control signal carrying only control information indicating the set of those decoded messages for which no error has been detected by the half-duplex relay and for transmitting the representative signal; and
after transmitting the control signal and receiving a feedback control signal from the destination in response to the transmitted control signal, transmit from the half-duplex relay to the destination the representative signal solely under condition of an authorization originating from the destination given by way of the feedback control signal.