Method and apparatus for monitoring control candidates

1. A method performed by a device, the method comprising:

receiving a configuration that configures a set of short physical downlink control channel candidates;

monitoring a first subset of the set of short physical downlink control channel candidates associated with a first set of aggregation levels in a first transmit time interval of a subframe; and

monitoring a second subset of the set of short physical downlink control channel candidates associated with a second set of aggregation levels in a second transmit time interval of the subframe;

wherein the first subset of the set of short physical downlink control channel candidates and the second subset of the short physical downlink control channel candidates are different at least in one short physical downlink control channel candidate,

wherein the first subset of the set of short physical downlink control channel candidates is based on a first index associated with the first transmit time interval within the subframe,

wherein the second subset of the set of short physical downlink control channel candidates is based on a second index associated with the second transmit time interval within the subframe,

wherein monitoring implies attempting to decode short physical downlink control channel candidates, and

wherein the subframe comprises at least the first and the second transmit time intervals.

2. The method according to claim 1 , wherein the first set of aggregation levels is different than the second set of aggregation levels.

3. The method according to claim 1 , wherein at least one selected from the first index associated with the first transmit time interval and the second index associated with the second transmit time interval comprises a shortened transmit time interval index associated with a transmit time interval with a length shorter than a length of a subframe.

4. The method according to claim 1 ,

wherein the first transmit time interval belongs to a first set of transmit time intervals and the second transmit time interval belongs to the second set of transmit time intervals, and

wherein the subframe comprises the first set of transmit time intervals and the second set of transmit time intervals.

5. The method according to claim 4 , wherein the first set of transmit time intervals comprises odd numbered transmit time intervals within the subframe and the second set of transmit time intervals comprises even numbered transmit time intervals within the subframe.

6. The method according to claim 1 , wherein at least one selected from the first index and the second index comprises a slot index.

7. The method according to claim 1 , wherein the first transmit time interval is in a first slot of the subframe and the second transmit time interval is in a second slot of the subframe, where the second slot is different from the first slot.

8. The method according to claim 1 , wherein a number of decoding candidates in the first subset of the set of short physical downlink control channel candidates is different than a number of decoding candidates the second subset of the set of short physical downlink control channel candidates.

9. The method according to claim 1 , wherein the second subset of the set of short physical downlink control channel candidates is based on the first subset of the set of short physical downlink control channel candidates.

10. The method according to claim 9 , further comprising deriving a position of short physical downlink control channel candidates of the second subset of the set of short physical downlink control channel candidates based on knowledge of positions of short physical downlink control channel candidates in the first subset of the set of short physical downlink control channel candidates.

11. The method according to claim 1 ,

wherein the first subset of the set of short physical downlink control channel candidates is mapped to a first set of physical resource block-sets,

wherein the second subset of the set of short physical downlink control channel candidates is mapped to a second set of physical resource block-sets, and

wherein the first set of physical resource block-sets and the second set of physical resource block-sets have at least one different physical resource block-set.

12. The method according to claim 1 , wherein a transmit time interval comprises a duration in which the device transmits and receives a transport block to and from higher layers than a physical layer.

13. An apparatus comprising:

a transceiver that receives a configuration that configures a set of short physical downlink control channel candidates; and

a controller coupled to the transceiver, where the controller

monitors a first subset of the set of short physical downlink control channel candidates associated with a first set of aggregation levels in a first transmit time interval of a subframe, and

monitors a second subset of the set of short physical downlink control channel candidates associated with a second set of aggregation levels in a second transmit time interval of the subframe,

wherein the first subset of the set of short physical downlink control channel candidates and the second subset of the short physical downlink control channel candidates are different at least in one short physical downlink control channel candidate,

wherein the first subset of the set of short physical downlink control channel candidates is based on a first index associated with the first transmit time interval within the subframe,

wherein the second subset of the set of short physical downlink control channel candidates is based on a second index associated with the second transmit time interval within the subframe,

wherein monitoring implies attempting to decode short physical downlink control channel candidates, and

wherein the subframe comprises at least the first and the second transmit time intervals.

14. The apparatus according to claim 13 , wherein the first set of aggregation levels is different than the second set of aggregation levels.

15. The apparatus according to claim 13 , wherein at least one selected from the first index associated with the first transmit time interval and the second index associated with the second transmit time interval comprises a shortened transmit time interval index associated with a transmit time interval with a length shorter than a length of a subframe.

16. The apparatus according to claim 13 ,

wherein the first transmit time interval belongs to a first set of transmit time intervals and the second transmit time interval belongs to the second set of transmit time intervals, and

wherein the subframe comprises the first set of transmit time intervals and the second set of transmit time intervals.

17. The apparatus according to claim 16 , wherein the first set of transmit time intervals comprises odd numbered transmit time intervals within the subframe and the second set of transmit time intervals comprises even numbered transmit time intervals within the subframe.

18. The apparatus according to claim 13 , wherein at least one selected from the first index and the second index comprises a slot index.

19. The apparatus according to claim 13 , wherein the first transmit time interval is in a first slot of the subframe and the second transmit time interval is in a second slot of the subframe, where the second slot is different from the first slot.

20. The apparatus according to claim 13 , wherein a number of decoding candidates in the first subset of the set of short physical downlink control channel candidates is different than a number of decoding candidates the second subset of the set of short physical downlink control channel candidates.