Common reference signals for multiple search spaces within a control resource set

1. A method for wireless communication, comprising:

identifying, at a base station, a control resource set (coreset) for a transmission time interval, the coreset including a common search space (CSS) and a user equipment (UE)-specific search space (USS);

identifying reference signals to transmit in the CSS and the USS of the coreset, the identified reference signals comprising a common sequence for the coreset; and

transmitting the identified reference signals in the CSS and the USS of the coreset.

2. The method of claim 1 , further comprising:

transmitting an indication of a configuration of the coreset in a physical broadcast channel (PBCH) or a radio resource control (RRC) message.

3. The method of claim 1 , further comprising:

identifying the common sequence for the coreset, wherein the common sequence is based at least in part on a radio network temporary identifier.

4. The method of claim 1 , further comprising:

precoding the coreset, including the identified reference signals, using a same precoder.

5. The method of claim 1 , further comprising:

precoding the coreset, including the identified reference signals, using a contiguous precoder.

6. The method of claim 1 , further comprising:

precoding each control channel element (CCE) of a plurality of CCEs of the coreset, including the identified reference signals, using one of a plurality of different precoders.

7. The method of claim 1 , further comprising:

precoding a plurality of resource element groups (REGs) of a control channel element (CCE) of the coreset, including the identified reference signals, using one of a plurality of different precoders for each of the plurality of REGs.

8. The method of claim 1 , wherein the coreset spans one or more symbols, the identified reference signals transmitted in the one or more symbols of the coreset.

9. The method of claim 1 , wherein the CSS has a first aggregation level, and the USS has a second aggregation level different than the first aggregation level.

10. The method of claim 1 , further comprising:

precoding the reference signals within a resource element group (REG) bundle of a plurality of REG bundles of the coreset using a same precoder or a contiguous precoder.

11. The method of claim 10 , wherein precoding the reference signals within each REG bundle of the plurality of REG bundles of the coreset comprises:

precoding the reference signals within a first REG bundle of the plurality of REG bundles using a first precoder; and

precoding the reference signals within a second REG bundle of the plurality of REG bundles using a second precoder different from the first precoder.

12. The method of claim 1 , further comprising:

precoding the reference signals across the coreset using a same precoder or a contiguous precoder.

13. A method for wireless communication at a user equipment (UE), comprising:

identifying a configuration for control resource sets (coresets), each coreset including a common search space (CSS) and a UE-specific search space (USS);

receiving a coreset during a transmission time interval;

identifying reference signals in the CSS and the USS of the received coreset, the identified reference signals comprising a common sequence for the coreset; and

decoding the CSS and the USS based at least in part on the identified reference signals.

14. The method of claim 13 , further comprising:

receiving an indication of the configuration of the coreset in a physical broadcast channel (PBCH) or a radio resource control (RRC) message.

15. The method of claim 13 , wherein decoding the CSS and the USS based at least in part on the identified reference signals comprises:

decoding the identified reference signals based at least in part on a radio network temporary identifier.

16. The method of claim 13 , further comprising:

performing channel estimation on a channel based at least in part on decoded reference signals, the channel carrying the received coreset.

17. The method of claim 16 , further comprising:

decoding control information in the CSS and the USS based at least in part on channel estimation performed on the channel.

18. The method of claim 13 , wherein the coreset spans one or more symbols, the identified reference signals received in the one or more symbols of the coreset.

19. An apparatus for wireless communication, comprising:

means for identifying, at a base station, a control resource set (coreset) for a transmission time interval, the coreset including a common search space (CSS) and a user equipment (UE)-specific search space (USS);

means for identifying reference signals to transmit in the CSS and the USS of the coreset, the identified reference signals comprising a common sequence for the coreset; and

means for transmitting the identified reference signals in the CSS and the USS of the coreset.

20. The apparatus of claim 19 , further comprising:

means for transmitting an indication of a configuration of the coreset in a physical broadcast channel (PBCH) or a radio resource control (RRC) message.

21. The apparatus of claim 19 , further comprising:

means for identifying the common sequence for the coreset, wherein the common sequence is based at least in part on a radio network temporary identifier.

22. An apparatus for wireless communication at a user equipment (UE), comprising:

means for identifying a configuration for control resource sets (coresets), each coreset including a common search space (CSS) and a UE-specific search space (USS);

means for receiving a coreset during a transmission time interval;

means for identifying reference signals in the CSS and the USS of the received coreset, the identified reference signals comprising a common sequence for the coreset; and

means for decoding the CSS and the USS based at least in part on the identified reference signals.

23. The apparatus of claim 22 , further comprising:

means for receiving an indication of the configuration of the coreset in a physical broadcast channel (PBCH) or a radio resource control (RRC) message.

24. The apparatus of claim 22 , wherein the means for decoding the CSS and the USS based at least in part on the identified reference signals comprises:

means for decoding the identified reference signals based at least in part on a radio network temporary identifier.

25. An apparatus for wireless communication, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:

identify, at a base station, a control resource set (coreset) for a transmission time interval, the coreset including a common search space (CSS) and a UE-specific search space (USS);

identify reference signals to transmit in the CSS and the USS of the coreset, the identified reference signals comprising a common sequence for the coreset; and

transmit the identified reference signals in the CSS and the USS of the coreset.

26. The apparatus of claim 25 , wherein the instructions are further executable by the processor to cause the apparatus to:

transmit an indication of a configuration of the coreset in a physical broadcast channel (PBCH) or a radio resource control (RRC) message.

27. The apparatus of claim 25 , wherein the instructions are further executable by the processor to cause the apparatus to:

identify the common sequence for the coreset, wherein the common sequence is based at least in part on a radio network temporary identifier.

28. The apparatus of claim 25 , wherein the instructions are further executable by the processor to cause the apparatus to:

precode the coreset, including the identified reference signals, using a same precoder.

29. The apparatus of claim 25 , wherein the instructions are further executable by the processor to cause the apparatus to:

precode the coreset, including the identified reference signals, using a contiguous precoder.

30. The apparatus of claim 25 , wherein the instructions are further executable by the processor to cause the apparatus to:

precode each control channel element (CCE) of a plurality of CCEs of the coreset, including the identified reference signals, using one of a plurality of different precoders.

31. The apparatus of claim 25 , wherein the instructions are further executable by the processor to cause the apparatus to:

precode a plurality of resource element groups (REGs) of a control channel element (CCE) of the coreset, including the identified reference signals, using one of a plurality of different precoders for each of the plurality of REGs.

32. The apparatus of claim 25 , wherein the coreset spans one or more symbols, the identified reference signals transmitted in the one or more symbols of the coreset.

33. The apparatus of claim 25 , wherein the CSS has a first aggregation level, and the USS has a second aggregation level different than the first aggregation level.

34. The apparatus of claim 25 , wherein the instructions are further executable by the processor to cause the apparatus to:

precode the reference signals within a resource element group (REG) bundle of a plurality of REG bundles of the coreset using a same precoder or a contiguous precoder.

35. The apparatus of claim 34 , wherein the instructions are further executable by the processor to cause the apparatus to:

precode the reference signals within a first REG bundle of the plurality of REG bundles using a first precoder; and

precode the reference signals within a second REG bundle of the plurality of REG bundles using a second precoder different from the first precoder.

36. The apparatus of claim 25 , wherein the instructions are further executable by the processor to cause the apparatus to:

precode the reference signals across the coreset using a same precoder or a contiguous precoder.

37. An apparatus for wireless communication, at a user equipment (UE) comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:

identify a configuration for control resource sets (coresets), each coreset including a common search space (CSS) and a UE-specific search space (USS);

receive a coreset during a transmission time interval;

identify reference signals in the CSS and the USS of the received coreset, the identified reference signals comprising a common sequence for the coreset; and

decode the CSS and the USS based at least in part on the identified reference signals.

38. The apparatus of claim 37 , wherein the instructions are further executable by the processor to cause the apparatus to:

receive an indication of the configuration of the coreset in a physical broadcast channel (PBCH) or a radio resource control (RRC) message.

39. The apparatus of claim 37 , wherein the instructions are further executable by the processor to cause the apparatus to:

decode the identified reference signals based at least in part on a radio network temporary identifier.

40. The apparatus of claim 37 , wherein the instructions are further executable by the processor to cause the apparatus to:

perform channel estimation on a channel based at least in part on decoded reference signals, the channel carrying the received coreset.

41. The apparatus of claim 40 , wherein the instructions are further executable by the processor to cause the apparatus to:

decode control information in the CSS and the USS based at least in part on the performing channel estimation on the channel.

42. The apparatus of claim 37 , wherein the coreset spans one or more symbols, the identified reference signals received in the one or more symbols of the coreset.

43. A non-transitory computer readable medium storing code for wireless communication, the code comprising instructions executable by a processor to:

identify, at a base station, a control resource set (coreset) for a transmission time interval, the coreset including a common search space (CSS) and a UE-specific search space (USS);

identify reference signals to transmit in the CSS and the USS of the coreset, the identified reference signals comprising a common sequence for the coreset; and

transmit the identified reference signals in the CSS and the USS of the coreset.

44. The non-transitory computer-readable medium of claim 43 , wherein the instructions are further executable by the processor to:

transmit an indication of a configuration of the coreset in a physical broadcast channel (PBCH) or a radio resource control (RRC) message.

45. The non-transitory computer-readable medium of claim 43 , wherein the instructions are further executable by the processor to:

identify the common sequence for the coreset, wherein the common sequence is based at least in part on a radio network temporary identifier.

46. A non-transitory computer readable medium storing code for wireless communication, the code comprising instructions executable by a processor to:

identify a configuration for control resource sets (coresets), each coreset including a common search space (CSS) and a UE-specific search space (USS);

receive a coreset during a transmission time interval;

identify reference signals in the CSS and the USS of the received coreset, the identified reference signals comprising a common sequence for the coreset; and

decode the CSS and the USS based at least in part on the identified reference signals.

47. The non-transitory computer-readable medium of claim 46 , wherein the instructions are further executable by the processor to:

receive an indication of the configuration of the coreset in a physical broadcast channel (PBCH) or a radio resource control (RRC) message.

48. The non-transitory computer-readable medium of claim 46 , wherein the instructions are further executable by the processor to:

decode the identified reference signals based at least in part on a radio network temporary identifier.