Method and a Device for Relaying in a Communications Network

• US 20130250776A1
• Filed: 08/09/2011
• Published: 09/26/2013
• Est. Priority Date: 08/19/2010
• Status: Active Grant

• Current Assignee: Orange S.A.
• Original Assignee: Orange S.A.
• Inventors: Hatefi, Atoosa, Visoz, Raphal, Berthet, Antoine
• Granted Patent: US 9,319,187 B2
• Time in Patent Office: Days
• US Class Current: 370/243
• CPC Class Codes: H03M 13/093 CRC update after modification of the information word
• CPC Class Codes: H04B 7/15521 combining by calculations packets received from different stations before transmitting the combined packets as part of network coding network coding aspects for detection or prevention of errors in the information received H04L1/0076; network traffic management with optimizing of information sizing, e.g. header compression, by using assembly and disassembly of packets H04W28/065
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/0083 Formatting with frames or packets; Protocol or part of protocol for error control
• CPC Class Codes: H04L 1/244 test sequence generators
• CPC Class Codes: H04L 2001/0097 Relays
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

A method and device for selective relaying in a communications network having a plurality of sources, a relay, and a destination. The method includes the following steps: the relay receives messages transmitted respectively by the sources in order to obtain an estimate of the messages; the relay detects errors in the estimated messages; the relay transmits a representative signal to the destination, the signal being representative of only those messages for which no error was detected and resulting from a non-bijective surjective function applied to the messages detected without error, the function including interleaving and encoding; and the representative signal being transmitted by the relay to the destination with a check signal indicating which messages are represented in the representative signal.

Claims

1. A selective relaying method in a communications network having a plurality of sources, a relay, and a destination, the method comprising:

the relay receiving messages transmitted respectively by the sources in order to obtain an estimate of the messages;

the relay detecting errors in the estimated messages;

the relay transmitting a representative signal to the destination, the signal being representative of only those messages for which no error was detected and resulting from a non-bijective surjective function applied to the messages detected without error, comprising interleaving and encoding; and

the representative signal being transmitted by the relay to the destination with a check signal indicating the at least one message represented in the representative signal.

2. The selective relaying method according to claim 1, wherein, in the event of at least two messages being detected without error, the representative signal results from a network and channel coding function that depends on the number of messages detected without error and that is applied to those messages for which no error was detected.

3. The selective relaying method according to claim 1, wherein the error detection step is performed by means of a CRC type code.

4. The selective relaying method in a communications network according to claim 2, wherein the network and channel coding function includes a step of modulo-2 addition of only those messages for which no error was detected.

5. The selective relaying method according to claim 4, wherein the modulo-2 addition of the messages is performed together with their respective CRC codes.

6. A selective relaying device for a communications network having a plurality of sources, and a destination, the relaying device comprising:

means for receiving messages transmitted respectively by the sources to obtain estimates of the messages;

means for detecting errors in the estimated messages;

means for transmitting a representative signal to the destination, the signal being representative of only those messages for which no error was detected and resulting from a non-bijective surjective function applied to the messages detected without error and comprising interleaving and encoding; and

the representative signal being transmitted by said relay device to the destination with a check signal indicating the at least one message represented in the representative signal.

11. A communications system including at least one relaying device according to claim 6 and at least one reception device according to claim 9.

7. A method of receiving messages, the message-reception method being implemented in a destination device of a MARC system having a plurality of sources and a relay, the method comprising:

receiving messages by the destination device from the sources;

receiving a representative signal by the destination device from the relay, wherein the representative signal is representative of the messages received from the sources without error by the relay

receiving a check signal by the destination device from the relay, wherein the check signal indicates which of the messages are represented in the representative signal; and

applying detection/decoding by the destination device jointly to the received messages coming from the sources and to the representative signal coming from the relay, under control of the check signal coming from the relay.

8. The method according to claim 7, wherein the representative signal comes from modulo-2 summing of the messages indicated by said check signal as being represented in said transmitted representative signal.

9. A message-reception device for a communications network having a plurality of sources and a relay, the device comprising:

means for receiving messages from the sources and for receiving a representative signal and a check signal from the relay, wherein the representative signal is representative of the messages received from the sources without error by the relay and the check signal indicates which of the messages are represented in the representative signal;

means for jointly detecting/decoding messages received from the sources and the received signal from the relay in iterative manner and under control of the check signal received from the relay.

10. The message-reception device according to claim 9, wherein the means for jointly detecting/decoding comprise decoders with soft inputs and soft outputs.