Distributed iterative decoding for co-operative diversity
View Patent ↗A source sends an encoded data block during a first time interval to a destination and to a relay. The source sends additional parity bits for the encoded data block during a second time interval. The relay partially decodes that encoded data block to a process-defined end point (typically only a partial decoding), such as a fixed number of decoding iterations. After partial decoding the relay forms a modified data block having corrected information bits and the parity bits of the block it received, and sends the modified data block to the destination, during the second time interval. The destination decodes to a results-defined end point the modified data block it received from the relay using the additional parity bits it received from the source. If that end-point cannot be reached, the destination may begin anew decoding the original encoded data block it received from the source.
1. A method comprising:
an apparatus receiving from a source during a first time interval an encoded data block;
the apparatus receiving from the source during a second time interval additional error correction data for the encoded data block;
the apparatus receiving from a relay a modified version of the encoded data block that is partially decoded and not further re-encoded as compared to the encoded data block; and
the apparatus decoding the modified version of the encoded data block received from the relay using the additional error correction data received from the source.
2. The method of claim 1 , wherein the modified version of the encoded data block comprises the encoded data block that is partially decoded to a process-defined end point, and wherein decoding the modified version of the encoded data block using the additional error correction data comprises decoding towards a results-defined end point.
3. The method of claim 2 , wherein for the case where decoding the modified version of the encoded data block using the additional error correction data fails to reach the results-defined end point, the method further comprising decoding the encoded data block received from the source to the results-defined end point.
4. The method of claim 1 , in which the apparatus comprises one of a base station and an access node, and wherein the modified version of the encoded data block is received in the second time interval.
5. The method of claim 1 , wherein the additional error correction data comprises parity bits for the encoded data block received from the source.
6. The method of claim 1 , wherein decoding the modified version of the encoded data block is with a code that differs from another code with which the encoded data block received from the source is encoded.
7. An apparatus, comprising:
at least one processor;
at least one memory including computer program code;
the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:
receive from a source during a first time interval an encoded data block;
receive from the source during a second time interval additional error correction data for the encoded data block;
receive from a relay a modified version of the encoded data block that is partially decoded and not further re-encoded as compared to the encoded data block; and
decode the modified version of the encoded data block received from the relay using the additional error correction data received from the source.
8. The apparatus of claim 7 ,
wherein the modified version of the encoded data block comprises the encoded data block that is partially decoded to a process-defined end point,
and wherein the apparatus is configured to decode the modified version of the encoded data block using the additional error correction data towards a results-defined end point.
9. The apparatus of claim 8 , wherein for the case where the apparatus fails to reach the results-defined end point when decoding the modified version of the encoded data block using the additional error correction data, the at least one processor is further configured to cause the apparatus to decode to the results-defined end point the encoded data block that is received from the source.
10. The apparatus of claim 7 , wherein the apparatus comprises one of a base station and an access node, and wherein the apparatus is configured to receive the modified version of the encoded data block in the second time interval.
11. The apparatus of claim 7 , wherein the additional error correction data comprises parity bits for the encoded data block received from the source.
12. The apparatus of claim 7 , wherein the apparatus is configured to decode the modified version of the encoded data block using a code that differs from another code with which is encoded the encoded data block that the apparatus received from the source.
13. A computer readable memory embodying a computer program that is executable by a processor to perform actions directed to distributed decoding, the actions comprising:
receiving from a source during a first time interval an encoded data block;
receiving from the source during a second time interval additional error correction data for the encoded data block;
receiving from a relay a modified version of the encoded data block that is partially decoded and not further re-encoded as compared to the encoded data block; and
decoding the modified version of the encoded data block received from the relay using the additional error correction data received from the source.
14. The computer readable memory of claim 13 , wherein the modified version of the encoded data block comprises the encoded data block that is partially decoded to a process-defined end point, and wherein decoding the modified version of the encoded data block using the additional error correction data comprises decoding towards a results-defined end point, and wherein the additional error correction data comprises parity bits for the encoded data block received from the source.
15. The computer readable memory of claim 13 , wherein for the case where decoding the modified version of the encoded data block using the additional error correction data fails to reach the results-defined end point, the actions further comprise decoding the encoded data block received from the source to the results-defined end point.
16. The computer readable memory of claim 13 , wherein decoding the modified version of the encoded data block is with a code that differs from another code with which the encoded data block received from the source is encoded.