IP Library › Granted Patent US 9,826,514

Granted Patent B2

US 9,826,514 · App. 13/676,961 · Granted Nov 21, 2017

Downlink control information (DCI) design for low cost devices

Inventors: Wanshi Chen (San Diego, CA); Hao Xu (San Diego, CA); Juan Montojo (Nuremberg, DE); Peter Gaal (San Diego, CA)

Assignee: QUALCOMM Incorporated

H04W72/042 H04L5/0053

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Quick Facts

Patent No.: US 9,826,514
App. No.: 13/676,961
Granted: Nov 21, 2017
Kind: B2

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Abstract

Certain aspects of the present disclosure relate to techniques for reducing the decoding complexity for low cost devices (e.g., low cost UEs). One technique may include simplifying the PDCCH format. This may include generating a compact DCI format for transmitting DCI to a low cost device. The compact DCI format may correspond to at least one standard DCI format used by a regular UE and may comprise a reduced number of bits when compared to the standard DCI format. Another technique may include reducing the number of blind decodes. This technique may include selecting a set of resources for transmitting DCI from a limited set of decoding candidates, such that a receiving low cost device need only perform blind decodes for the limited set of decoding candidates.

Claims (163)

1. A method for wireless communications, comprising:

generating a compact Downlink Control Information (DCI) format for transmitting DCI for use in at least one of uplink (UL) or downlink (DL) transmissions by a first device of a first type, wherein the compact DCI format corresponds to at least one standard DCI format used by a second device of a second type and comprises a reduced number of bits when compared to the at least one standard DCI format; and

transmitting the DCI according to the compact DCI format,

wherein the DCI comprises DCI for a limited modulation and coding scheme (MCS), and wherein the limited MCS comprises Quadrature Phase Shift Keying (QPSK) only with a limited set of possible coding rates.

2. The method of claim 1 , wherein a device of the first type comprises reduced processing capability when compared to a device of the second type.

3. The method of claim 1 , wherein the first device comprises a low cost User Equipment (UE).

4. The method of claim 1 , wherein generating the DCI comprises:

generating the DCI without bits allocated for resource allocation information, wherein the DCI allocates resources for one user at a time.

5. A method for wireless communications, comprising:

transmitting the DCI according to the compact DCI format,

wherein the DCI comprises

DCI for a limited set of resource allocation possibilities.

6. The method of claim 1 , wherein generating the DCI comprises:

generating the DCI for a limited set of Hybrid Automatic Repeat Request (HARQ) processes.

7. The method of claim 6 , wherein the DCI lacks an indication of a HARQ process.

8. The method of claim 1 , wherein generating the DCI comprises:

generating the DCI without a bit allocated for differentiating between DCI formats 1A and 0, wherein the DCI formats 1A and 0 have different sizes.

9. The method of claim 1 , wherein generating the DCI comprises:

generating a reduced length Cyclic Redundancy Check (CRC) for the DCI.

10. The method of claim 9 , wherein generating the reduced length CRC comprises:

generating a CRC of a first length and truncating the CRC of the first length to generate the reduced length CRC.

11. The method of claim 1 , wherein generating the DCI comprises:

generating the DCI without bits allocated for Redundancy Version (RV).

12. The method of claim 1 , wherein generating the DCI comprises:

generating the DCI without bits allocated for Sounding Reference Signal (SRS) request.

13. The method of claim 1 , wherein generating the DCI comprises:

generating the DCI with reduced bit-width for Transmitter Power Control (TPC).

14. The method of claim 1 , wherein generating the DCI comprises:

generating the DCI with reduced bit-width for Demodulation Reference Signal (DM-RS).

15. A method for wireless communications, comprising:

transmitting the DCI according to the compact DCI format,

wherein the DCI comprises

DCI without a bit allocated for a multi-cluster flag.

16. A method for wireless communications, comprising:

transmitting the DCI according to the compact DCI format,

wherein the DCI comprises

DCI without a bit allocated for Virtual Resource Block assignment.

17. The method of claim 1 , further comprising

determining whether periodic channel state information (CSI) is supported;

keeping aperiodic CSI if periodic CSI is not supported; and

removing aperiodic CSI if periodic CSI is supported.

18. A method for wireless communications, comprising:

transmitting the DCI according to the compact DCI format,

wherein the DCI comprises

DCI without a bit allocated for frequency hopping flag.

19. A method for wireless communications, comprising:

transmitting the DCI according to the compact DCI format,

wherein the DCI comprises

DCI without a bit allocated for Downlink Assignment Index (DAI) and UL assignment index, wherein a one to one mapping is maintained between DL subframe and UL subframe for each UE.

20. A method for wireless communications, comprising:

transmitting the DCI according to the compact DCI format,

further comprising:

selecting a set of resources for transmitting the DCI from a limited set of decoding candidates; and

transmitting the DCI using the selected set of resources, such that a receiving UE need only perform blind decodes for the limited set of decoding candidates.

21. An apparatus for wireless communications, comprising:

means for generating a compact Downlink Control Information (DCI) format for transmitting DCI for use in at least one of uplink (UL) or downlink (DL) transmissions by a first device of a first type, wherein the compact DCI format corresponds to at least one standard DCI format used by a second device of a second type and comprises a reduced number of bits when compared to the at least one standard DCI format; and

means for transmitting the DCI according to the compact DCI format,

22. The apparatus of claim 21 , wherein a device of the first type comprises reduced processing capability when compared to a device of the second type.

23. The apparatus of claim 21 , wherein the first device comprises a low cost User Equipment (UE).

24. An apparatus for wireless communications, comprising:

means for transmitting the DCI according to the compact DCI format,

further comprising:

means for selecting a set of resources for transmitting the DCI from a limited set of decoding candidates; and

means for transmitting the DCI using the selected set of resources, such that a receiving UE need only perform blind decodes for the limited set of decoding candidates.

25. An apparatus for wireless communications, comprising:

at least one processor configured to:

generate a compact Downlink Control Information (DCI) format for transmitting DCI for use in at least one of uplink (UL) or downlink (DL) transmissions by a first device of a first type, wherein the compact DCI format corresponds to at least one standard DCI format used by a second device of a second type and comprises a reduced number of bits when compared to the at least one standard DCI format; and

transmit the DCI according to the compact DCI format,

a memory coupled to the at least one processor.

26. A non-transitory computer-readable medium for wireless communications the non-transitory computer-readable medium comprising code for:

transmitting the DCI according to the compact DCI format,

27. A method for wireless communications by a first device of a first type, comprising:

receiving Downlink Control Information (DCI) according to a compact DCI format for use in at least one of uplink (UL) or downlink (DL) transmissions, wherein the compact DCI format corresponds to at least one standard DCI format used by a second device of a second type and comprises a reduced number of bits when compared to the at least one standard DCI format; and

processing the received DCI,

28. The method of claim 27 , wherein a device of the first type comprises reduced processing capability when compared to a device of the second type.

29. The method of claim 27 , wherein the first device comprises a low cost User Equipment (UE).

30. The method of claim 27 , wherein the DCI comprises:

DCI without bits allocated for resource allocation information, wherein the DCI allocates resources for one user at a time.

31. A method for wireless communications by a first device of a first type, comprising:

processing the received DCI,

wherein the DCI comprises:

DCI for a limited set of resource allocation possibilities.

32. The method of claim 27 , wherein the DCI comprises:

DCI for a limited set of Hybrid Automatic Repeat Request (HARQ) processes.

33. The method of claim 32 , wherein the DCI lacks an indication of a HARQ process.

34. The method of claim 27 , wherein the DCI comprises:

DCI without a bit allocated for differentiating between DCI formats 1A and 0, wherein the DCI formats 1A and 0 have different sizes.

35. The method of claim 27 , wherein the DCI comprises:

a reduced length Cyclic Redundancy Check (CRC) for the DCI.

36. The method of claim 35 , wherein the reduced length CRC comprises:

a CRC generated by generating a CRC of a first length and truncating the CRC of the first length to generate the reduced length CRC.

37. The method of claim 27 , wherein the DCI comprises:

DCI without bits allocated for Redundancy Version (RV).

38. The method of claim 27 , wherein the DCI comprises:

DCI without bits allocated for Sounding Reference Signal (SRS) request.

39. The method of claim 27 , wherein the DCI comprises:

DCI with reduced bit-width for Transmitter Power Control (TPC).

40. The method of claim 27 , wherein the DCI comprises:

DCI with reduced bit-width for Demodulation Reference Signal (DM-RS).

41. A method for wireless communications by a first device of a first type, comprising:

processing the received DCI,

wherein the DCI comprises:

DCI without a bit allocated for multi-cluster flag.

42. The method of claim 27 , wherein the DCI comprises:

DCI with aperiodic channel state information (CSI) if periodic CSI is not supported; and

DCI without aperiodic CSI if periodic CSI is supported.

43. A method for wireless communications by a first device of a first type, comprising:

processing the received DCI,

wherein the DCI comprises:

DCI without a bit allocated for Virtual Resource Block assignment.

44. A method for wireless communications by a first device of a first type, comprising:

processing the received DCI,

wherein the DCI comprises:

DCI without a bit allocated for a frequency hopping flag.

45. A method for wireless communications by a first device of a first type, comprising:

processing the received DCI,

wherein the DCI comprises:

DCI without a bit allocated for Downlink Assignment Index (DAI) and UL assignment index, wherein a one to one mapping is maintained between DL subframe and UL subframe for each UE.

46. A method for wireless communications by a first device of a first type, comprising:

processing the received DCI,

wherein:

the DCI is transmitted using a set of resources selected from a limited set of decoding candidates; and

the method comprises performing blind decodes for the limited set of decoding candidates to detect a PDCCH containing the DCI.

47. An apparatus for wireless communications by a first device of a first type, comprising:

means for receiving Downlink Control Information (DCI) according to a compact DCI format for use in at least one of uplink (UL) or downlink (DL) transmissions, wherein the compact DCI format corresponds to at least one standard DCI format used by a second device of a second type and comprises a reduced number of bits when compared to the at least one standard DCI format; and

means for processing the received DCI,

48. The apparatus of claim 47 , wherein a device of the first type comprises reduced processing capability when compared to a device of the second type.

49. The apparatus of claim 47 , wherein the first device comprises a low cost User Equipment (UE).

50. An apparatus for wireless communications by a first device of a first type, comprising:

means for processing the received DCI,

wherein:

the DCI is transmitted using a set of resources selected from a limited set of decoding candidates; and

the apparatus comprises means for performing blind decodes for the limited set of decoding candidates to detect a PDCCH containing the DCI.

51. An apparatus for wireless communications by a first device of a first type, comprising:

at least one processor configured to:

receive Downlink Control Information (DCI) according to a compact DCI format for use in at least one of uplink (UL) or downlink (DL) transmissions, wherein the compact DCI format corresponds to at least one standard DCI format used by a second device of a second type and comprises a reduced number of bits when compared to the at least one standard DCI format; and

process the received DCI,

a memory coupled to the at least one processor.

52. A non-transitory computer-readable medium for wireless communications by a first device of a first type, the non-transitory computer-readable medium comprising code for:

processing the received DCI,

Assignments (1)

ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 10, 2013

From: CHEN, WANSHI; XU, HAO; MONTOJO, JUAN; GAAL, PETER

To: QUALCOMM INCORPORATED

Reel/Frame 030764/0448 →

Continuity (2)

Provisional Application 61560337 · Nov 16, 2011

Related Publication 20130121274A1 · May 16, 2013