Decoding tail-biting convolutional codes

1. A user equipment (UE), comprising:

at least one component configured to decode a tail-biting convolution code (TBCC) by calculating a plurality of paths that correspond to a plurality of encoder starting states and trace back at least one of the calculated paths per at least one iteration until a trace-back convergence check (TCC) condition fails,

wherein the TCC condition fails if a starting state of a first traced back path among the calculated paths is not equal to a starting state of a subsequent traced back path.

2. The UE of claim 1 , wherein the TBCC is received in a Physical Control Channel (PDCCH).

3. The UE of claim 1 , wherein the TCC condition is not used during a first iteration and only a first calculated path is traced-back during the first iteration.

4. The UE of claim 1 , wherein the calculated paths are ordered based on their corresponding calculated state metrics before tracing back the calculated paths.

5. The UE of claim 4 , wherein the first traced back path has the highest value state metric and the subsequent traced back path has a lower value state metric.

6. The UE of claim 4 , wherein the first traced back path has the lowest value state metric and the subsequent traced back path has a higher value state metric.

7. The UE of claim 1 , wherein the first traced back path is used to obtain a match to an original bit stream that corresponds to the TBCC before encoding if the first traced back path is a tail-biting path.

8. The UE of claim 1 , wherein the subsequent traced back path is used to obtain a match to an original bit stream that corresponds to the TBCC before encoding if the subsequent traced back path is a tail-biting path and the first traced back path is not a trail-biting path.

9. The UE of claim 1 , wherein the first traced back path is used to obtain a match to an original bit stream that corresponds to the TBCC before encoding if none of the calculated paths is a tail-biting path.

10. An access device, comprising:

at least one component configured to decode a tail-biting convolution code (TBCC) by calculating a plurality of paths that correspond to a plurality of encoder starting states in at least one iteration and trace back at least one of the calculated paths per at least one iteration until a trace-back convergence check (TCC) condition fails,

wherein the TCC condition fails if a starting state of a first traced back path among the calculated paths is not equal to a starting state of a subsequent traced back path.

11. The access device of claim 10 , wherein the TCC condition is not used during a first iteration and only a first calculated path is traced-back during the first iteration.

12. The access device of claim 10 , wherein the calculated paths are ordered based on their corresponding calculated state metrics before tracing back the calculated paths.

13. The access device of claim 12 , wherein the first traced back path has the highest value state metric and the subsequent traced back path has a lower value state metric.

14. The access device of claim 12 , wherein the first traced back path has the lowest value state metric and the subsequent traced back path has a higher value state metric.

15. The access device of claim 10 , wherein the first traced back path is used to obtain a match to an original bit stream that corresponds to the TBCC before encoding if the first traced back path is a tail-biting path.

16. The access device of claim 10 , wherein the subsequent traced back path is used to obtain a match to an original bit stream that corresponds to the TBCC before encoding if the subsequent traced back path is a tail-biting path and the first trail-biting path is not a trail-biting path.

17. The access device of claim 10 , wherein the first traced back path is used to obtain a match to an original bit stream that corresponds to the TBCC before encoding if none of the calculated paths is a tail-biting path.

18. A method implemented on a device, comprising;

receiving a tail-biting convolution code (TBCC);

calculating a plurality of paths that correspond to a plurality encoder starting states of the TBCC in at least one iteration; and

tracing back at least one of the calculated paths per at least one iteration until a trace-back convergence check (TCC) condition fails,

wherein the TCC condition fails if a starting state of a first traced back path among the calculated paths is not equal to a starting state of a subsequent traced back path.

19. The method of claim 18 further comprising:

sorting the computed paths based on their corresponding calculated state metrics;

tracing back at least one of the computed paths in the sorted order until a trail-biting path is found, a TCC condition fails, or all the computed paths are traced back; and

using the tail-biting path or the first traced back path if the tail-biting path is not found to obtain a match to an original bit stream that corresponds to the TBCC before encoding.

20. The method of claim 19 , wherein the first traced back path has a highest value state metric and the subsequent traced back path has a lower value state metric.

21. The method of claim 19 , wherein the first traced back path has a lowest value state metric and the subsequent traced back path has a higher value state metric.

22. The method of claim 18 , wherein the TBCC is received in a Physical Control Channel (PDCCH).

23. The method of claim 18 , wherein the TCC condition is not used during a first iteration and all the computed paths are traced-back during the first iteration.

24. The method of claim 18 , wherein the device is one of a user equipment (UE), an access device, or any network connectivity device.