Network node, UE and methods therein for detecting a damaged transmission of data due to data puncturing

1. A method performed by a network node for handling a damaged transmission of data due to data puncturing, the method comprising:

receiving, from a User Equipment (UE), a Negative Acknowledgment (NACK) feedback of a previous transmission of data transmitted to the UE;

checking whether or not the data is punctured in the previous transmission corresponding to the NACK feedback;

when the data is punctured in the previous transmission, selecting a Redundancy Version (RV) for a retransmission of the data, according to characteristics of the punctured data and puncturing data; and

sending a Puncturing Indication (PI), the selected RV, and the retransmission of the data to the UE.

2. The method of claim 1 , wherein the retransmission uses the selected RV.

3. The method of claim 1 , wherein, when the puncturing data and the punctured data have the same characteristics, the selecting the RV comprises selecting the RV to be an RV that in terms of bit positions partially or fully overlaps with the RV used in the previous transmission.

4. The method of claim 3 , wherein the RV is selected so that the overlapping part coincides with the punctured part of the previous transmission.

5. The method of claim 1 , wherein, when the puncturing data and the punctured data have different characteristics, the selecting the RV comprises selecting the RV to maximize coding gain.

6. The method of claim 5 , further comprising relying on the UE to detect the differences of the characteristics of the puncturing data and the punctured data.

7. A method performed by a User Equipment (UE) for detecting a damaged transmission of data due to data puncturing, the method comprising:

receiving, from a network node, a retransmission of data of a previous transmission transmitted to the UE by the network node, a Puncturing Indication (PI), and a Redundancy Version (RV) for the retransmission;

checking the PI to determine whether or not the data is punctured in the previous transmission of data; and

detecting the puncturing data based on the RV when the data is punctured in the previous transmission.

8. The method of claim 7 , wherein the received RV is used in the retransmission.

9. The method of claim 8 , further comprising removing soft-information for the detected puncturing data of the previous transmission from a soft-buffer, before further processing the retransmission.

10. The method of claim 7 , further comprising:

checking the RV of the retransmission when the data is punctured in the previous transmission;

if the RV, in terms of bit positions, partially or fully overlaps with the RV used in the previous transmission, performing the detecting of the puncturing data by using a correlation in characteristics between the previous transmission and the retransmission; and

performing soft combining of soft information of the previous transmission and soft information of the retransmission.

11. The method of claim 7 , further comprising:

checking the RV of the retransmission when the data is punctured in the previous transmission;

if the same RV is used in the retransmission as in the previous transmission, performing the detecting of the puncturing data by using a correlation in characteristics between the previous transmission and the retransmission; and

performing Chase combining of soft information of the previous transmission and soft information of the retransmission.

12. The method of claim 10 , wherein the soft combining of soft information of the previous transmission and soft information of the retransmission is performed after the detected puncturing data is removed from a soft buffer.

13. The method of claim 7 , further comprising:

checking the RV of the retransmission when the data is punctured in the previous transmission;

if a different RV is used in the retransmission compared to the previous transmission, performing the detecting of the puncturing data by using a difference in characteristics between the puncturing data and the punctured data in the previous transmission; and

performing soft combining of soft information of the previous transmission and soft information of the retransmission based on Incremental Redundancy (IR).

14. The method of claim 13 , wherein the performing soft combining of soft information of the previous transmission and soft information of the retransmission is performed after the detected puncturing data is removed from a soft buffer.

15. The method of claim 7 :

wherein the puncturing data and punctured data have different characteristics; and

wherein the detecting of the puncturing data is performed by detecting the differences of different characteristics of the puncturing data and the punctured data.

16. A network node for handling a damaged transmission of data due to data puncturing, the network node comprising:

processing circuitry; and

memory containing instructions executable by the processing circuitry whereby the network node is operative to:

receive, from a User Equipment (UE), a Negative Acknowledgment (NACK) feedback of a previous transmission of data transmitted to the UE;

check whether or not the data is punctured in the previous transmission corresponding to the NACK feedback;

when the data is punctured in the previous transmission, select a Redundancy Version (RV) for a retransmission of the data, according to characteristics of the punctured data and puncturing data; and

send a Puncturing Indication (PI), the selected RV, and the retransmission of the data to the UE.

17. A User Equipment (UE) for detecting a damaged transmission of data due to data puncturing, the UE comprising:

processing circuitry; and

memory containing instructions executable by the processing circuitry whereby the UE is operative to:

receive, from a network node, a retransmission of data of a previous transmission transmitted to the UE by the network node, a Puncturing Indication (PI), and a Redundancy Version (RV) for the retransmission;

check the PI whether or not the data is punctured in the previous transmission of data; and

detect the puncturing data based on the RV when the data is punctured in the previous transmission.