Structure of enhanced physical downlink control channel (e-PDCCH) in long term evolution (LTE)
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to defining a structure of and enhanced physical downlink control channel (e-PDCCH). Certain aspects provide methods and apparatus for determining a search space in which a base station (eNodeB) may transmit an enhanced physical downlink control channel (e-PDCCH), wherein the search space comprises one or more fractional portions of frequency-time resources of a physical resource block (PRB) pair, and attempting to decode the e-PDCCH based on the determined search space.
1. A method for wireless communications, comprising:
determining a search space in which a base station may transmit an enhanced physical downlink control channel (e-PDCCH), wherein the search space comprises one or more fractional portions of frequency-time resources of a physical resource block (PRB) pair; and
attempting to decode the e-PDCCH based on the determined search space,
wherein a multiplexing capability for the e-PDCCH in the PRB pair depends on a subframe type.
2. The method of claim 1 , wherein the fractional portion of resources comprises frequency division multiplexed resources.
3. The method of claim 1 , wherein the fractional portion of resources comprises interleaved tones.
4. The method of claim 1 , further comprising:
transmitting a demodulation reference signal (DM-RS) with a pattern corresponding to a maximum possible rank regardless of a number of e-PDCCH transmitted in the PRB pair.
5. The method of claim 1 , wherein each fractional portion of frequency-time resources is associated with an antenna port for demodulation.
6. The method of claim 1 , wherein a mapping of e-PDCCH to the one or more fractional portions of frequency-time resources follows a frequency-first, time-second manner.
7. The method of claim 1 , wherein for a subframe containing channel state information-reference signal (CSI-RS) or downlink pilot time slot (DwPTS), the multiplexing capability is smaller than that of a regular downlink subframe.
8. The method of claim 7 , wherein the multiplexing capability is smaller when a number of resource elements (REs) for e-PDCCH is below a threshold.
9. The method of claim 1 , wherein the multiplexing capability of an e-PDCCH in a PRB pair with an extended cyclic prefix is smaller than that of a PRB pair with a normal cyclic prefix.
10. An apparatus for wireless communications, comprising:
means for determining a search space in which a base station may transmit an enhanced physical downlink control channel (e-PDCCH), wherein the search space comprises one or more fractional portions of frequency-time resources of a physical resource block (PRB) pair; and
means for attempting to decode the e-PDCCH based on the determined search space,
wherein a multiplexing capability for an e-PDCCH in the PRB pair depends on a subframe type.
11. The apparatus of claim 10 , wherein the fractional portion of resources comprises frequency division multiplexed resources.
12. The apparatus of claim 10 , wherein the fractional portion of resources comprises interleaved tones.
13. The apparatus of claim 10 , further comprising:
means for transmitting a demodulation reference signal (DM-RS) with a pattern corresponding to a maximum possible rank regardless of a number of e-PDCCH transmitted in the PRB pair.
14. The apparatus of claim 10 , wherein each fractional portion of frequency-time resources is associated with an antenna port for demodulation.
15. The apparatus of claim 10 , wherein a mapping of e-PDCCH to the one or more fractional portions of frequency-time resources follows a frequency-first, time-second manner.
16. The apparatus of claim 10 , wherein for a subframe containing channel state information-reference signal (CSI-RS) or downlink pilot time slot (DwPTS), the multiplexing capability is smaller than that of a regular downlink subframe.
17. The apparatus of claim 16 , wherein the multiplexing capability is smaller when a number of resource elements (REs) for e-PDCCH is below a threshold.
18. The apparatus of claim 10 , wherein the multiplexing capability of an e-PDCCH in a PRB pair with an extended cyclic prefix is smaller than that of a PRB pair with a normal cyclic prefix.
19. An apparatus for wireless communications, comprising:
at least one processor configured to:
determine a search space in which a base station may transmit an enhanced physical downlink control channel (e-PDCCH), wherein the search space comprises one or more fractional portions of frequency-time resources of a physical resource block (PRB) pair; and
attempt to decode the e-PDCCH based on the determined search space; and
a memory coupled to the at least one processor,
wherein a multiplexing capability for an e-PDCCH in the PRB pair depends on a subframe type.
20. The apparatus of claim 19 , wherein the fractional portion of resources comprises frequency division multiplexed resources.
21. The apparatus of claim 19 , wherein the fractional portion of resources comprises interleaved tones.
22. The apparatus of claim 19 , wherein the at least one processor is further configured to:
transmit a demodulation reference signal (DM-RS) with a pattern corresponding to a maximum possible rank regardless of a number of e-PDCCH transmitted in the PRB pair.
23. The apparatus of claim 19 , wherein each fractional portion of frequency-time resources is associated with an antenna port for demodulation.
24. The apparatus of claim 19 , wherein a mapping of e-PDCCH to the one or more fractional portions of frequency-time resources follows a frequency-first, time-second manner.
25. The apparatus of claim 19 , wherein for a subframe containing channel state information-reference signal (CSI-RS) or downlink pilot time slot (DwPTS), the multiplexing capability is smaller than that of a regular downlink subframe.
26. The apparatus of claim 25 , wherein the multiplexing capability is smaller when a number of resource elements (REs) for e-PDCCH is below a threshold.
27. The apparatus of claim 19 , wherein the multiplexing capability of an e-PDCCH in a PRB pair with an extended cyclic prefix is smaller than that of a PRB pair with a normal cyclic prefix.
28. A computer-program product for wireless communications, the computer-program product comprising a non-transitory computer-readable medium having code stored thereon, the code executable by one or more processors for:
determining a search space in which a base station may transmit an enhanced physical downlink control channel (e-PDCCH), wherein the search space comprises one or more fractional portions of frequency-time resources of a physical resource block (PRB) pair; and
attempting to decode the e-PDCCH based on the determined search space,
wherein a multiplexing capability for an e-PDCCH in the PRB pair depends on a subframe type.
29. The computer-program product of claim 28 , wherein the fractional portion of resources comprises frequency division multiplexed resources.
30. The computer-program product of claim 28 , wherein the fractional portion of resources comprises interleaved tones.
31. The computer-program product of claim 28 , further comprising code for:
transmitting a demodulation reference signal (DM-RS) with a pattern corresponding to a maximum possible rank regardless of a number of e-PDCCH transmitted in the PRB pair.
32. The computer-program product of claim 28 , wherein each fractional portion of frequency-time resources is associated with an antenna port for demodulation.
33. The computer-program product of claim 28 , wherein a mapping of e-PDCCH to the one or more fractional portions of frequency-time resources follows a frequency-first, time-second manner.
34. The computer-program product of claim 28 , wherein for a subframe containing channel state information-reference signal (CSI-RS) or downlink pilot time slot (DwPTS), the multiplexing capability is smaller than that of a regular downlink subframe.
35. The computer-program product of claim 34 , wherein the multiplexing capability is smaller when a number of resource elements (REs) for e-PDCCH is below a threshold.
36. The computer-program product of claim 28 , wherein the multiplexing capability of an e-PDCCH in a PRB pair with an extended cyclic prefix is smaller than that of a PRB pair with a normal cyclic prefix.
37. A method for wireless communications, comprising:
determining a search space of resources available for transmitting an enhanced physical downlink control channel (e-PDCCH), wherein the search space comprises one or more fractional portions of frequency-time resources of a physical resource block (PRB) pair; and
transmitting the e-PDCCH utilizing resources of the determined search space,
wherein a multiplexing capability for an e-PDCCH in the PRB pair depends on a subframe type.
38. The method of claim 37 , wherein the fractional portion of resources comprises frequency division multiplexed resources.
39. The method of claim 37 , wherein the fractional portion of resources comprises interleaved tones.
40. The method of claim 37 , further comprising:
receiving a demodulation reference signal (DM-RS) with a pattern corresponding to a maximum possible rank regardless of a number of e-PDCCH transmitted in the PRB pair.
41. The method of claim 37 , wherein each fractional portion of frequency-time resources is associated with an antenna port for demodulation.
42. The method of claim 37 , wherein a mapping of e-PDCCH to the one or more fractional portions of frequency-time resources follows a frequency-first, time-second manner.
43. The method of claim 37 , wherein for a subframe containing channel state information-reference signal (CSI-RS) or downlink pilot time slot (DwPTS), the multiplexing capability is smaller than that of a regular downlink subframe.
44. The method of claim 43 , wherein the multiplexing capability is smaller when a number of resource elements (REs) for e-PDCCH is below a threshold.
45. The method of claim 37 , wherein the multiplexing capability of an e-PDCCH in a PRB pair with an extended cyclic prefix is smaller than that of a PRB pair with a normal cyclic prefix.
46. An apparatus for wireless communications, comprising:
means for determining a search space of resources available for transmitting an enhanced physical downlink control channel (e-PDCCH), wherein the search space comprises one or more fractional portions of frequency-time resources of a physical resource block (PRB) pair; and
means for transmitting the e-PDCCH utilizing resources of the determined search space,
wherein a multiplexing capability for an e-PDCCH in the PRB pair depends on a subframe type.
47. The apparatus of claim 46 , wherein the fractional portion of resources comprises frequency division multiplexed resources.
48. The apparatus of claim 46 , wherein the fractional portion of resources comprises interleaved tones.
49. The apparatus of claim 46 , further comprising:
means for receiving a demodulation reference signal (DM-RS) with a pattern corresponding to a maximum possible rank regardless of a number of e-PDCCH transmitted in the PRB pair.
50. The apparatus of claim 46 , wherein each fractional portion of frequency-time resources is associated with an antenna port for demodulation.
51. The apparatus of claim 46 , wherein a mapping of e-PDCCH to the one or more fractional portions of frequency-time resources follows a frequency-first, time-second manner.
52. The apparatus of claim 46 , wherein for a subframe containing channel state information-reference signal (CSI-RS) or downlink pilot time slot (DwPTS), the multiplexing capability is smaller than that of a regular downlink subframe.
53. The apparatus of claim 52 , wherein the multiplexing capability is smaller when a number of resource elements (REs) for e-PDCCH is below a threshold.
54. The apparatus of claim 46 , wherein the multiplexing capability of an e-PDCCH in a PRB pair with an extended cyclic prefix is smaller than that of a PRB pair with a normal cyclic prefix.
55. An apparatus for wireless communications, comprising:
at least one processor configured to:
determine a search space of resources available for transmitting an enhanced physical downlink control channel (e-PDCCH), wherein the search space comprises one or more fractional portions of frequency-time resources of a physical resource block (PRB) pair; and
transmit the e-PDCCH utilizing resources of the determined search space; and
a memory coupled to the at least one processor,
wherein a multiplexing capability for an e-PDCCH in the PRB pair depends on a subframe type.
56. The apparatus of claim 55 , wherein the fractional portion of resources comprises frequency division multiplexed resources.
57. The apparatus of claim 55 , wherein the fractional portion of resources comprises interleaved tones.
58. The apparatus of claim 55 , wherein the at least one processor is further configured to:
receive a demodulation reference signal (DM-RS) with a pattern corresponding to a maximum possible rank regardless of a number of e-PDCCH transmitted in the PRB pair.
59. The apparatus of claim 55 , wherein each fractional portion of frequency-time resources is associated with an antenna port for demodulation.
60. The apparatus of claim 55 , wherein a mapping of e-PDCCH to the one or more fractional portions of frequency-time resources follows a frequency-first, time-second manner.
61. The apparatus of claim 55 , wherein for a subframe containing channel state information-reference signal (CSI-RS) or downlink pilot time slot (DwPTS), the multiplexing capability is smaller than that of a regular downlink subframe.
62. The apparatus of claim 61 , wherein the multiplexing capability is smaller when a number of resource elements (REs) for e-PDCCH is below a threshold.
63. The apparatus of claim 55 , wherein the multiplexing capability of an e-PDCCH in a PRB pair with an extended cyclic prefix is smaller than that of a PRB pair with a normal cyclic prefix.
64. A computer-program product for wireless communications, the computer-program product comprising a non-transitory computer-readable medium having code stored thereon, the code executable by one or more processors for:
determining a search space of resources available for transmitting an enhanced physical downlink control channel (e-PDCCH), wherein the search space comprises one or more fractional portions of frequency-time resources of a physical resource block (PRB) pair; and
transmitting the e-PDCCH utilizing resources of the determined search space,
wherein a multiplexing capability for an e-PDCCH in the PRB pair depends on a subframe type.
65. The computer-program product of claim 64 , wherein the fractional portion of resources comprises frequency division multiplexed resources.
66. The computer-program product of claim 64 , wherein the fractional portion of resources comprises interleaved tones.
67. The computer-program product of claim 64 , further comprising:
code for receiving a demodulation reference signal (DM-RS) with a pattern corresponding to a maximum possible rank regardless of a number of e-PDCCH transmitted in the PRB pair.
68. The computer-program product of claim 64 , wherein each fractional portion of frequency-time resources is associated with an antenna port for demodulation.
69. The computer-program product of claim 64 , wherein a mapping of e-PDCCH to the one or more fractional portions of frequency-time resources follows a frequency-first, time-second manner.
70. The computer-program product of claim 64 , wherein for a subframe containing channel state information-reference signal (CSI-RS) or downlink pilot time slot (DwPTS), the multiplexing capability is smaller than that of a regular downlink subframe.
71. The computer-program product of claim 70 , wherein the multiplexing capability is smaller when a number of resource elements (REs) for e-PDCCH is below a threshold.
72. The computer-program product of claim 64 , wherein the multiplexing capability of an e-PDCCH in a PRB pair with an extended cyclic prefix is smaller than that of a PRB pair with a normal cyclic prefix.