Reference signals for an enhanced physical downlink control channel

1. A method of wireless communication, comprising:

generating a demodulation reference signal (DM-RS) based at least in part on a single scrambling identifier (ID) having a value of 2;

generating a user equipment specific reference signal (UE-RS) based at least in part on a single scrambling ID having a value of 0 or 1, the value of the single scrambling ID for the DM-RS being different from the value of the single scrambling ID of the UE-RS such that the DM-RS is distinguishable from the UE-RS;

transmitting the DM-RS for an enhanced control channel that uses resources selected from at least a data region of a subframe; and

transmitting the UE-RS for a data channel that uses resources selected from the data region.

2. The method of claim 1 , in which the enhanced control channel comprises an enhanced physical downlink control channel (EPDCCH) and the data channel comprises a physical downlink shared channel (PDSCH).

3. The method of claim 1 , in which the DM-RS is also based at least in part on a cell identifier that is configured separately from the cell identifier of the UE-RS.

4. The method of claim 3 , in which the cell identifier comprises a physical cell identifier (PCI).

5. The method of claim 3 , in which the cell identifier comprises a virtual cell identifier.

6. A method of wireless communication, comprising:

receiving a reference signal; and

determining whether the reference signal is a demodulation reference signal (DM-RS) associated with an enhanced control channel or a user equipment specific reference signal (UE-RS) associated with a data channel based at least in part on a value of a single scrambling identifier (ID), the enhanced control channel using resources selected from at least a data region of a subframe and the data channel using resources selected from the data region, the reference signal being the DM-RS when the value of the single scrambling ID is 2, the reference signal being the UE-RS when the value of the single scrambling ID is 0 or 1, and the value of the single scrambling ID for the DM-RS being different from the value of the single scrambling ID of the UE-RS such that the DM-RS is distinguishable from the UE-RS.

7. The method of claim 6 , in which the enhanced control channel comprises an enhanced physical downlink control channel (EPDCCH) and the data channel comprises a physical downlink shared channel (PDSCH).

8. The method of claim 6 , in which the reference signal is further based on a cell identifier common for the enhanced control channel and the data channel.

9. The method of claim 6 , in which the reference signal is further based on:

a first cell identifier for the enhanced control channel, and

a second cell identifier for the data channel, the second cell identifier being configured separately from the first cell identifier.

10. The method of claim 6 , in which the reference signal is received within a physical resource block (PRB).

11. A method of wireless communication, comprising:

receiving a reference signal from a cell;

determining whether a channel associated with the reference signal is an enhanced control channel, such that the reference signal is a demodulation reference signal (DM-RS), or a data channel, such that the reference signal is a user equipment specific reference signal (UE-RS), the enhanced control channel using resources selected from at least a data region of a subframe, and the data channel using resources selected from the data region;

determining a value for a single scrambling identifier (ID) for the reference signal based on the determined channel, the value being 2 for the DM-RS, the value being 0 or 1 for the UE-RS, and the value of the single scrambling ID for the DM-RS being different from the value of the single scrambling ID of the UE-RS such that the DM-RS is distinguishable from the UE-RS; and

processing the determined channel based at least in part on the determined value scrambling ID.

12. The method of claim 11 , in which the enhanced control channel comprises an enhanced physical downlink control channel (EPDCCH) and the data channel comprises a physical downlink shared channel (PDSCH).

13. The method of claim 11 , in which the reference signal is further based on a cell identifier, the cell identifier being configured separately for the UE-RS and the DM-RS.

14. The method of claim 13 , in which the cell identifier comprises a physical cell identifier (PCI).

15. The method of claim 13 , in which the cell identifier comprises a virtual cell identifier.

16. The method of claim 11 , in which the reference signal is received within a physical resource block (PRB).

17. An apparatus for wireless communications, comprising:

a memory; and

at least one processor coupled to the memory, the at least one processor being configured:

to generate a demodulation reference signal (DM-RS) based at least in part on a single scrambling identifier (ID) having a value of 2;

to generate a user equipment specific reference signal (UE-RS) based at least in part on a single scrambling ID having a value of 0 or 1, the value of the single scrambling ID for the DM-RS being different from the value of the single scrambling ID of the UE-RS such that the DM-RS is distinguishable from the UE-RS;

to transmit the DM-RS for an enhanced control channel that uses resources selected from at least a data region of a subframe; and

to transmit the UE-RS for a data channel that uses resources selected from the data region.

18. The apparatus of claim 17 , in which the enhanced control channel comprises an enhanced physical downlink control channel (EPDCCH) and the data channel comprises a physical downlink shared channel (PDSCH).

19. The apparatus of claim 17 , in which the DM-RS is further based on a cell identifier that is configured separately from the cell identifier of the UE-RS.

20. The apparatus of claim 19 , in which the cell identifier comprises a physical cell identifier (PCI).

21. The apparatus of claim 19 , in which the cell identifier comprises a virtual cell identifier.

22. An apparatus for wireless communications, comprising:

a memory; and

at least one processor coupled to the memory, the at least one processor being configured:

to receive a reference signal; and

to determine whether the reference signal is a demodulation reference signal (DM-RS) associated with an enhanced control channel or a user equipment specific reference signal (UE-RS) associated with a data channel based at least in part on a value of a single scrambling identifier (ID), the enhanced control channel using resources selected from at least a data region of a subframe and the data channel using resources selected from the data region, the reference signal being the DM-RS when the value of the single scrambling ID is 2, the reference signal being the UE-RS when the value of the single scrambling ID is 0 or 1, and the value of the single scrambling ID for the DM-RS being different from the value of the single scrambling ID of the UE-RS such that the DM-RS is distinguishable from the UE-RS.

23. The apparatus of claim 22 , in which the reference signal comprises a demodulation reference signal (DM-RS).

24. The apparatus of claim 22 , in which the enhanced control channel comprises an enhanced physical downlink control channel (EPDCCH) and the data channel comprises a physical downlink shared channel (PDSCH).

25. The apparatus of claim 22 , in which the reference signal is further based on a cell identifier common for the enhanced control channel and the data channel.

26. The apparatus of claim 22 , in which the reference signal is further based on:

a first cell identifier for the enhanced control channel, and

a second cell identifier for the data channel, the second cell identifier being configured separately from the first cell identifier.

27. The apparatus of claim 22 , in which the reference signal is received within a physical resource block (PRB).

28. An apparatus for wireless communications, comprising:

a memory; and

at least one processor coupled to the memory, the at least one processor being configured:

to receive a reference signal from a cell;

to determine whether a channel associated with the reference signal is an enhanced control channel, such that the reference signal is a demodulation reference signal (DM-RS), or a data channel, such that the reference signal is a user equipment specific reference signal (UE-RS), the enhanced control channel using resources selected from at least a data region of a subframe, and the data channel using resources selected from the data region;

to determine a value for a single scrambling identifier (ID) for the reference signal based on the determined channel, the value being 2 for the DM-RS, the value being 0 or 1 for the UE-RS, and the value of the single scrambling ID for the DM-RS being different from the value of the single scrambling ID of the UE-RS such that the DM-RS is distinguishable from the UE-RS; and

to process the determined channel based at least in part on the determined scrambling ID value.

29. The apparatus of claim 28 , in which the enhanced control channel comprises an enhanced physical downlink control channel (EPDCCH) and the data channel comprises a physical downlink shared channel (PDSCH).

30. The apparatus of claim 28 , in which the reference signal is further based on a cell identifier, the cell identifier being configured separately for the UE-RS and the DM-RS.

31. The apparatus of claim 30 , in which the cell identifier comprises a physical cell identifier (PCI).

32. The apparatus of claim 30 , in which the cell identifier comprises a virtual cell identifier.

33. The apparatus of claim 28 , in which the reference signal comprises received within a physical resource block (PRB).

34. An apparatus for wireless communications, comprising:

means for generating a demodulation reference signal (DM-RS) based at least in part on a single scrambling identifier (ID) having a value of 2;

means for generating a user equipment specific reference signal (UE-RS) based at least in part on a single scrambling ID having a value of 0 or 1, the value of the single scrambling ID for the DM-RS being different from the value of the single scrambling ID of the UE-RS such that the DM-RS is distinguishable from the UE-RS;

means for transmitting the DM-RS for an enhanced control channel that uses resources selected from at least a data region of a subframe; and

means for transmitting the UE-RS for a data channel that uses resources selected from the data region.

35. An apparatus for wireless communications, comprising:

means for receiving a reference signal; and

means for determining whether the reference signal is a demodulation reference signal (DM-RS) associated with an enhanced control channel or a user equipment specific reference signal (UE-RS) associated with a data channel based at least in part on a value of a single scrambling identifier (ID), the enhanced control channel using resources selected from at least a data region of a subframe and the data channel using resources selected from the data region, the reference signal being the DM-RS when the value of the single scrambling ID is 2, the reference signal being the UE-RS when the value of the single scrambling ID is 0 or 1, and the value of the single scrambling ID for the DM-RS being different from the value of the single scrambling ID of the UE-RS such that the DM-RS is distinguishable from the UE-RS.

36. An apparatus for wireless communications, comprising:

means for receiving a reference signal from a cell;

means for determining whether a channel associated with the reference signal is an enhanced control channel, such that the reference signal is a demodulation reference signal (DM-RS), or a data channel, such that the reference signal is a user equipment specific reference signal (UE-RS), the enhanced control channel using resources selected from at least a data region of a subframe, and the data channel using resources selected from the data region;

means for determining a value for a single scrambling identifier (ID) for the reference signal based on the determined channel, the value being 2 for the DM-RS, the value being 0 or 1 for the UE-RS, and the value of the single scrambling ID for the DM-RS being different from the value of the single scrambling ID of the UE-RS such that the DM-RS is distinguishable from the UE-RS; and

means for processing the determined channel based at least in part on the value determined for the single scrambling ID.

37. A non-transitory computer-readable medium having program code recorded thereon, the program code comprising:

program code to generate a demodulation reference signal (DM-RS) based at least in part on a single scrambling identifier (ID) having a value of 2;

program code to generate a user equipment specific reference signal (UE-RS) based at least in part on a single scrambling ID having a value of 0 or 1, the value of the single scrambling ID for the DM-RS being different from the value of the single scrambling ID of the UE-RS such that the DM-RS is distinguishable from the UE-RS;

program code to transmit the DM-RS for an enhanced control channel that uses resources selected from at least a data region of a subframe; and

program code to transmit the UE-RS for a data channel that uses resources selected from the data region.

38. A non-transitory computer-readable medium having program code recorded thereon, the program code comprising:

program code to receive a reference signal; and

program code to determine whether the reference signal is a demodulation reference signal (DM-RS) associated with an enhanced control channel or a user equipment specific reference signal (UE-RS) associated with a data channel based at least in part on a value of a single scrambling identifier (ID), the enhanced control channel using resources selected from at least a data region of a subframe and the data channel using resources selected from the data region, the reference signal being the DM-RS when the value of the single scrambling ID is 2, the reference signal being the UE-RS when the value of the single scrambling ID is 0 or 1, and the value of the single scrambling ID for the DM-RS being different from the value of the single scrambling ID of the UE-RS such that the DM-RS is distinguishable from the UE-RS.

39. A non-transitory computer-readable medium having program code recorded thereon, the program code comprising:

program code to receive a reference signal from a cell;

program code to determine whether a channel associated with the reference signal is an enhanced control channel, such that the reference signal is a demodulation reference signal (DM-RS), or a data channel, such that the reference signal is a user equipment specific reference signal (UE-RS), the enhanced control channel using resources selected from at least a data region of a subframe, and the data channel using resources selected from the data region;

program code to determine a value for a single scrambling identifier (ID) for the reference signal based on the determined channel, the value being 2 for the DM-RS, the value being 0 or 1 for the UE-RS, and the value of the single scrambling ID for the DM-RS being different from the value of the single scrambling ID of the UE-RS such that the DM-RS is distinguishable from the UE-RS; and

program code to process the determined channel based at least in part on the determined scrambling ID value.