Cross carrier scheduling

1. A method comprising:

receiving by a wireless device, configuration parameters indicating:

a linkage between a first search space (SS), of a scheduled cell, and a second SS, of a first bandwidth part (BWP) of a scheduling cell; and

that a third SS, of the scheduled cell, is not linked to any SSs of a second BWP of the scheduling cell;

monitoring, in response to the linkage and the first BWP being active, the second SS for receiving a scheduling indication for the scheduled cell;

switching from the first BWP to the second BWP as an active BWP of the scheduling cell;

monitoring, in response to the switching and the third SS not being linked to the any SSs of the second BWP, the third SS for receiving downlink control information (DCI) for the scheduled cell; and

receiving, via the third SS, the DCI for transmission on the scheduled cell.

2. The method of claim 1 , wherein the configuration parameters indicate the linkage between the first SS and the second SS in response to the first SS and the second SS having a same SS index.

3. The method of claim 1 , wherein the configuration parameters comprise one or more configuration parameters of a control resource set of the scheduled cell, wherein:

the third SS is associated with the control resource set; and

the one or more configuration parameters, of the control resource set, comprise:

a control resource set index identifying the control resource set;

a frequency resource indication; and

a time domain duration indication.

4. The method of claim 1 , wherein the wireless device switches from the first BWP to the second BWP as the active BWP in response to an expiry of a BWP inactivity timer.

5. The method of claim 1 , wherein the second SS, of the first BWP of the scheduling cell, is associated with search space configuration parameters comprising at least one of:

a search space index identifying the second SS;

a control resource set index of a control resource set associated with the second SS;

a number of slots for PDCCH monitoring for the second SS;

a slot offset indicator for PDCCH monitoring for the second SS;

a duration indicator;

a number of symbols within a slot for PDCCH monitoring for the second SS;

a number of PDCCH candidates; and

a search space type.

6. The method of claim 5 , wherein the first SS, in response to being linked to the second SS, is associated with the same search space configuration parameters except for the number of PDCCH candidates.

7. The method of claim 1 , further comprising receiving, via the second SS of the scheduling cell, the scheduling indication of a transmission of a first transport block on the scheduled cell.

8. The method of claim 7 , wherein the scheduling indication is comprised in a second DCI indicating a cross-carrier scheduling.

9. The method of claim 1 , wherein the wireless device switches from the first BWP to the second BWP as the active BWP in response to receiving a command indicating the switching.

10. The method of claim 9 , wherein the command comprises a power saving indication in at least one of:

a radio resource control message;

a medium access control element; and

a second DCI.

11. A wireless device comprising:

one or more processors; and

memory storing instructions that, when executed by the one or more processors, cause the wireless device to:

receive configuration parameters indicating:

a linkage between a first search space (SS), of a scheduled cell, and a second SS, of a first bandwidth part (BWP) of a scheduling cell; and

that a third SS, of the scheduled cell, is not linked to any SSs of a second BWP of the scheduling cell;

monitor, in response to the linkage and the first BWP being active, the second SS for receiving a scheduling indication for the scheduled cell;

switch from the first BWP to the second BWP as an active BWP of the scheduling cell;

monitor, in response to the switching and the third SS not being linked to the any SSs of the second BWP, the third SS for receiving downlink control information (DCI) for the scheduled cell; and

receive, via the third SS, the DCI for transmission on the scheduled cell.

12. The wireless device of claim 11 , wherein the configuration parameters indicate the linkage between the first SS and the second SS in response to the first SS and the second SS having a same SS index.

13. The wireless device of claim 11 , wherein the configuration parameters comprise one or more configuration parameters of a control resource set of the scheduled cell, wherein:

the third SS is associated with the control resource set; and

the one or more configuration parameters, of the control resource set, comprise:

a control resource set index identifying the control resource set;

a frequency resource indication; and

a time domain duration indication.

14. The wireless device of claim 11 , wherein the wireless device switches from the first BWP to the second BWP as the active BWP in response to an expiry of a BWP inactivity timer.

15. The wireless device of claim 11 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to receive, via the second SS of the scheduling cell, the scheduling indication of a transmission of a first transport block on the scheduled cell.

16. The wireless device of claim 11 , wherein the second SS, of the first BWP of the scheduling cell, is associated with search space configuration parameters comprising at least one of:

a search space index identifying the second SS;

a control resource set index of a control resource set associated with the second SS;

a number of slots for PDCCH monitoring for the second SS;

a slot offset indicator for PDCCH monitoring for the second SS;

a duration indicator;

a number of symbols within a slot for PDCCH monitoring for the second SS;

a number of PDCCH candidates; and

a search space type.

17. The wireless device of claim 16 , wherein the first SS, in response to being linked to the second SS, is associated with the same search space configuration parameters except for the number of PDCCH candidates.

18. The wireless device of claim 11 , wherein the wireless device switches from the first BWP to the second BWP as the active BWP in response to receiving a command indicating the switch.

19. The wireless device of claim 18 , wherein the command comprises a power saving indication in at least one of:

a radio resource control message;

a medium access control element; and

a second DCI.

20. A system comprising:

a base station comprising:

one or more first processors; and

memory storing first instructions that, when executed by the one or more first processors, cause the base station to:

transmit configuration parameters indicating:

a linkage between a first search space (SS), of a scheduled cell, and a second SS, of a first bandwidth part (BWP) of a scheduling cell; and

that a third SS, of the scheduled cell, is not linked to any SSs of a second BWP of the scheduling cell; and

a wireless device comprising:

one or more second processors; and

memory storing second instructions that, when executed by the one or more second processors, cause the wireless device to:

receive the configuration parameters;

monitor, in response to the linkage and the first BWP being active, the second SS for receiving a scheduling indication for the scheduled cell;

switch from the first BWP to the second BWP as an active BWP of the scheduling cell;

monitor, in response to the switching and the third SS not being linked to the any SSs of the second BWP, the third SS for receiving downlink control information (DCI) for the scheduled cell; and

receive, via the third SS, the DCI for transmission on the scheduled cell.