Methods and apparatus for synchronizing critical data transmission

1. A method, implemented by base station in a wireless communication network, of synchronizing a periodic data transmission, each data transmission of the periodic data transmission comprising a predetermined number of repetitions, the method comprising:

sending a first Semi-Persistent Scheduling (SPS) configuration to a user equipment for the periodic data transmission, the SPS configuration including a SPS period and an offset;

allocating available SPS resources within the SPS period for the periodic data transmission, wherein a number of SPS resources allocated for the periodic data transmission exceeds the number of repetitions in each data transmission;

receiving a data transmission from, or sending a data transmission to, the user equipment in a first SPS period;

determining a new SPS configuration based on a timing of the data transmission to synchronize the SPS period with the periodic data transmission; and

sending the new SPS configuration to the user equipment.

2. The method of claim 1 , wherein the determining the new SPS configuration comprises:

determining a timing of an initial repetition of the data transmission relative to a start of the SPS period; and

determining the new SPS configuration based on the timing of the initial repetition of the data transmission.

3. The method of claim 2 , wherein the determining the new SPS configuration comprises:

determining, based on the timing of the initial repetition of the data transmission, one or more candidate SPS configurations with different timing offsets;

for each candidate SPS configuration, determining a data transmission time for the data transmission; and

selecting the candidate SPS configuration with the lowest data transmission time as the new SPS configuration.

4. The method of claim 1 , wherein the determining the new SPS configuration comprises adjusting the offset compared to the first SPS configuration.

5. The method of claim 1 , wherein the allocating available SPS resources comprises allocating all available SPS resources within the SPS period to the user equipment for the periodic data transmission.

6. The method of claim 1 , wherein the allocating available SPS resources comprises allocating less than all available SPS resources within the SPS period to the user equipment for the periodic data transmission.

7. The method of claim 1 , wherein the number of repetitions equals one.

8. The method of claim 1 , further comprising adjusting the allocation of SPS resources for the periodic data transmission after determining the new SPS configuration.

9. The method of claim 8 , wherein the adjusting the allocation of SPS resources for the periodic data transmission comprises allocating a number of available SPS resources for the periodic data transmission equal to the number of repetitions.

10. The method of claim 1 , further comprising:

detecting a non-periodic data transmission from the user equipment during one of the SPS periods; and

responsive to detecting the non-periodic data transmission, adjusting a resource allocation for the periodic data transmission.

11. The method of claim 1 , wherein the periodic data transmission comprises an uplink transmission from the user equipment to the base station.

12. The method of claim 11 :

wherein the allocating available SPS resources comprises allocating less than all available SPS resources within the SPS period to the user equipment for the periodic data transmission; and

wherein the allocating less than all available SPS resources within the SPS period to the user equipment for the periodic data transmission comprises:

obtaining assistance information from the user equipment indicating a data packet arrival time for the periodic data transmission; and

allocating available SPS resources within the SPS period based on the assistance information.

13. The method of claim 1 , wherein the data transmission comprises a downlink transmission from the base station to the user equipment.

14. The method of claim 13 , wherein the data transmission comprises padding data.

15. The method of claim 13 , further comprising applying different cyclic shifts in reference signals for padding data and non-padding data in the periodic data transmission.

16. A method, implemented by a user equipment in a wireless communication network, of synchronizing a periodic downlink transmission between the user equipment and a base station, the method comprising:

receiving, from the base station, a Semi-Persistent Scheduling (SPS) configuration for the periodic downlink transmission, the SPS configuration including an SPS period and an offset;

receiving, from the base station, an allocation of available SPS resources in the SPS period for the periodic downlink transmission, wherein a number of SPS resources allocated for the periodic downlink transmission exceeds the number of repetitions in each downlink transmission;

blindly detecting and receiving a downlink transmission from the base station on allocated SPS resources according to the SPS configuration;

detecting a cyclic shift of a reference signal in the downlink transmission; and

determining, based on the cyclic shift, if the downlink transmission comprises padding data or non-padding data.

17. A base station in a wireless communication network configured to synchronize a periodic data transmission, each data transmission of the periodic data transmission comprising a predetermined number of repetitions, the base station comprising:

interface circuitry; and

processing circuitry operatively connected to the interface circuitry and configured to:

send a first Semi-Persistent Scheduling (SPS) configuration to a user equipment for the periodic data transmission, the SPS configuration including a SPS period and an offset;

allocate available SPS resources within the SPS period for the periodic data transmission, wherein a number of SPS resources allocated for the periodic data transmission exceeds the number of repetitions;

receive a data transmission from, or sending a data transmission to, the user equipment;

determine a new SPS configuration based on a timing of the data transmission to synchronize the SPS period with the periodic data transmission; and

send the new SPS configuration to the user equipment.

18. A user equipment in a wireless communication network configured to receive a periodic downlink transmission from a base station, the user equipment comprising:

interface circuitry; and

processing circuitry operatively connected to the interface circuitry and configured to:

receive, from the base station, a Semi-Persistent Scheduling (SPS) configuration for the periodic downlink transmission, the SPS configuration including an SPS period and an offset;

receive, from the base station, an allocation of available SPS resources in the SPS period for the periodic downlink transmission, wherein a number of SPS resources allocated for the periodic downlink transmission exceeds the number of repetitions in each downlink transmission; and

blindly detect and receive a downlink transmission from the base station on allocated SPS resources according to the SPS configuration;

detect a cyclic shift of a reference signal in the downlink transmission; and

determine, based on the cyclic shift, if the downlink transmission comprises padding data or non-padding data.