Base station and data retransmission method thereof

1. A data retransmission method applicable to a base station, wherein the data retransmission method comprises:

determining whether at least one data unit is delivered;

in response to the at least one data unit being undelivered, calculating data sizes corresponding to undelivered data units;

determining a resource grant indication according to the data sizes, wherein the resource grant indication is related to radio resources required for resending the undelivered data units; and

sending the resource grant indication.

2. The data retransmission method according to claim 1 , wherein the step of calculating the data sizes corresponding to the undelivered data units comprises:

in response to receiving or sending of a status report, summing up the data sizes corresponding to all the undelivered data units to generate a to-be-granted size, wherein the status report is related to the undelivered data units; and

determining the resource grant indication according to the to-be-granted size summed up from the data sizes.

3. The data retransmission method according to claim 2 , wherein the step of determining the resource grant indication according to the to-be-granted size summed up from the data sizes comprises:

determining whether a current resource grant indication is configured;

in response to absence of the current resource grant indication, determining, according to the to-be-granted size, a data amount corresponding to a new resource grant indication; and

in response to existence of the current resource grant indication, determining, according to a result obtained through comparison of the to-be-granted size with a data amount corresponding to the current resource grant indication, the data amount corresponding to the new resource grant indication.

4. The data retransmission method according to claim 3 , wherein the step of determining, according to the result obtained through comparison of the to-be-granted size with the data amount corresponding to the current resource grant indication, the data amount corresponding to the new resource grant indication comprises:

in response to the to-be-granted size being less than a maximum allowable grant size, determining, according to the to-be-granted size, the data amount corresponding to the new resource grant indication; and

in response to the to-be-granted size being not less than the maximum allowable grant size, using the data amount corresponding to the current resource grant indication as the data amount corresponding to the new resource grant indication.

5. The data retransmission method according to claim 2 , wherein the step of receiving or sending the status report comprises:

in response to the undelivered data units of a protocol layer corresponding to an automatic retransmission request mechanism, triggering receiving or sending of the status report.

6. The data retransmission method according to claim 2 , wherein after the step of sending the resource grant indication, the method further comprises:

in response to the undelivered data units being delivered after being resent, updating the to-be-granted size according to data sizes corresponding to the delivered data units.

7. A base station, comprising:

a receiving circuit configured to receive a signal;

a transmission circuit configured to send a signal; and

a processing circuit coupled to the receiving circuit and the transmission circuit and configured to:

determine whether at least one data unit is delivered;

in response to the at least one data unit being undelivered, calculating data sizes corresponding to undelivered data units;

determine a resource grant indication according to the data sizes, wherein the resource grant indication is related to radio resources required for resending the undelivered data units; and

send the resource grant indication through the transmission circuit.

8. The base station according to claim 7 , wherein the processing circuit is configured to:

in response to receiving or sending of a status report, sum up the data sizes corresponding to all the undelivered data units to generate a to-be-granted size, wherein the status report is related to the undelivered data units; and

determine the resource grant indication according to the to-be-granted size summed up from the data sizes.

9. The base station according to claim 8 , wherein the processing circuit is configured to:

determine whether a current resource grant indication is configured;

in response to absence of the current resource grant indication, determine, according to the to-be-granted size, a data amount corresponding to a new resource grant indication; and

in response to existence of the current resource grant indication, determine, according to a result obtained through comparison of the to-be-granted size with a data amount corresponding to the current resource grant indication, the data amount corresponding to the new resource grant indication.

10. The base station according to claim 9 , wherein the processing circuit is configured to:

in response to the to-be-granted size being less than a maximum allowable grant size, determine, according to the to-be-granted size, the data amount corresponding to the new resource grant indication; and

in response to the to-be-granted size being not less than the maximum allowable grant size, use the data amount corresponding to the current resource grant indication as the data amount corresponding to the new resource grant indication.

11. The base station according to claim 8 , wherein the processing circuit is configured to:

in response to the undelivered data units of a protocol layer corresponding to an automatic retransmission request mechanism, trigger receiving or sending of the status report.

12. The base station according to claim 8 , wherein the processing circuit is configured to:

in response to the undelivered data units being delivered after being resent, update the to-be-granted size according to data sizes corresponding to the delivered data units.