DMRS Association and Signaling for Enhanced PDCCH in LTE Systems

• US 20130064216A1
• Filed: 09/11/2012
• Published: 03/14/2013
• Est. Priority Date: 09/12/2011
• Status: Abandoned Application

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Gao, Shiwei, Xu, Hua, Jia, Yongkang, Mobasher, Amin
• Application Number:
  US13/610,464
• Publication Number:
  US 20130064216A1
• Time in Patent Office: Days
• US Class Current: 370/330
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0606 Random or pseudo-random switching scheme
• CPC Class Codes: H04L 1/1861 Physical mapping arrangements for ACK signaling see also H04L5/0053
• CPC Class Codes: H04L 5/0016 Time-frequency-code
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0026 Division using four or more dimensions
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling

Abstract

A method is provided for operating a UE in a wireless communication network. The method comprises sending, by the UE, an ACK/NACK message after receiving data on a PDSCH scheduled by an E-PDCCH, wherein the sending is from at least one antenna port and uses at least one physical resource, and wherein the at least one physical resource is determined based at least partially on a resource over which the E-PDCCH is received, and wherein the resource over which the E-PDCCH is received consists of at least one eCCE.

Claims

1. A method of operating a user equipment (UE) in a wireless communications network, the method comprising:

sending, by the UE, an acknowledgement/negative acknowledgement (ACK/NACK) message after receiving data on a physical downlink shared channel (PDSCH) scheduled by an extended physical downlink control channel (E-PDCCH), wherein the sending is from at least one antenna port and uses at least one physical resource, and wherein the at least one physical resource is determined based at least partially on a resource over which the E-PDCCH is received, and wherein the resource over which the E-PDCCH is received consists of at least one extended control channel element (eCCE).

2. The method of claim 1, further comprising using, by the UE, an eCCE index of the at least one eCCE to derive the physical resource for the ACK/NACK.

3. The method claim 1 further comprising using, by the UE, the lowest index of the eCCE for the E-PDCCH transmission, plus a DMRS port offset, to derive the physical resource for the ACK/NACK.

4. The method of claim 3, wherein the DMRS offset is the port index difference between the DMRS port associated with the eCCE with the lowest index and the DMRS port with which the E-PDCCH is demodulated.

5. The method of claim 1, further comprising using, by the UE, a signaling from a network element, wherein the signaling includes at least one of an ACK/NACK resource offset and a seed identifier (SCID) for DMRS sequence generation, for deriving the physical resource for the ACK/NACK.

6. The method of claim 1, further comprising using, by the UE, a transmit antenna port offset for deriving the physical resource for the ACK/NACK transmitted on a second transmit antenna.

7. The method of claim 5, wherein the physical resource index for the ACK/NACK is derived by a combination of one or more of the following parameters:

an eCCE index;

a DMRS port offset;

the ACK/NACK resource offset;

the SCID value; and

a transmit antenna port offset.

8. A method of operating an enhanced node B (eNB) in a wireless communications network, the method comprising:

detecting, by the eNB, from a user equipment (UE), an acknowledgement/negative acknowledgement (ACK/NACK) message after a physical downlink shared channel (PDSCH) scheduled by an extended physical downlink control channel (E-PDCCH) is transmitted to the UE, wherein the detection of the ACK/NACK is over at least one physical resource, and wherein the at least one physical resource is determined based at least partially on a resource over which the E-PDCCH is transmitted, and wherein the resource over which the E-PDCCH is transmitted consists of at least one extended control channel element (eCCE).

9. The method of claim 8, wherein the physical resource for the ACK/NACK is derived from an eCCE index of the at least one eCCE.

10. The method claim 8 wherein the physical resource for the ACK/NACK is derived from the lowest index of the eCCE for the E-PDCCH transmission, plus a DMRS port offset.

11. The method of claim 10, wherein the DMRS offset is the port index difference between the DMRS port associated with the eCCE with the lowest index and the DMRS port with which the E-PDCCH is transmitted.

12. The method of claim 8, further comprising the eNB using at least one of an ACK/NACK resource offset and a seed identifier (SCID) for DMRS sequence generation for deriving the physical resource for the ACK/NACK.

13. The method of claim 8, wherein a transmit antenna port offset is used for deriving a second physical resource for the ACK/NACK when the ACK/NACK is also transmitted on a second transmit antenna by the UE.

14. The method of claim 12, wherein the physical resource index for the ACK/NACK is derived by a combination of one or more of the following parameters:

an eCCE index;

a DMRS port offset;

the ACK/NACK resource offset;

the SCID value; and

a transmit antenna port offset.

15. A method for operating an enhanced node B (eNB) in a wireless communications network, the method comprising:

determining, by the eNB, an antenna port out of a set of antenna ports for sending a user equipment (UE) an enhanced physical downlink control channel (E-PDCCH), the determining being based at least partly on a time and frequency resource for the E-PDCCH and an offset parameter; and

sending, by the eNB to the UE, the E-PDCCH and a demodulation reference signal associated with the antenna port.

16. The method of claim 15, wherein the time and frequency resource comprises one or more enhanced control channel elements (eCCEs), and wherein each of the eCCEs comprises a plurality of resource elements (REs) within a physical resource block (PRB) pair, and wherein a PRB pair comprises a plurality of eCCEs.

17. The method of claim 16, wherein the eCCEs available for E-PDCCH transmission for the UE are indexed starting from zero.

18. The method of claim 16 wherein the antenna port index is determined by the following equation:

Antenna port index=A starting antenna port index of the set of antenna ports+function(the time and frequency resource)+offset value indicated by the offset parameter.

19. The method of claim 18, wherein the offset parameter has a value of zero if the E-PDCCH is transmitted over one eCCE.

20. The method of claim 18, wherein the function is given by the following equation:

function(the time and frequency resource)=(index of the first eCCE of the time and frequency resource)mod(number eCCEs per PRB pair)

wherein x mod(N) is a modulo N operation on x.

21. The method of claim 18, wherein the offset parameter is semi-statically signaled by the eNB to the UE through radio resource control (RRC) signaling.

22. The method of claim 18, wherein the offset parameter is a function of the UE'"'"'s radio network temporary identifier (RNTI).

23. The method of claim 22, wherein the function is a modulo two function.

24. The method of claim 18, wherein the offset parameter is a function of both the UE'"'"'s RNTI and the subframe number over which the E-PDCCH is transmitted.

25. The method of claim 24, wherein the function is given by the following equation:

Offset parameter at subframe k=Y_k mod(2)

wherein Y_k=(A·

Y<sub>k−

1</sub>)mod D, Y<sub>k−

1</sub>=n_RNTI, A=39827, D=65537, n_RNTI is the value of RNTI.

26. A method of operating a user equipment (UE) in a wireless communications network, the method comprising:

determining an antenna port of an enhanced physical downlink control channel (E-PDCCH) candidate based at least partly on a time and frequency resource for the E-PDCCH candidate and an offset parameter; and

receiving the E-PDCCH candidate using a demodulation reference signal associated with the antenna port.

27. The method of claim 26, wherein the time and frequency resource comprises one or more enhanced control channel elements (eCCEs), and wherein each of the eCCEs comprises a plurality of resource elements (REs) within a physical resource block (PRB) pair, and wherein a PRB pair comprises a plurality of eCCEs.

28. The method of claim 27, wherein the eCCEs available for E-PDCCH transmission in the network are indexed starting from zero.

29. The method of claim 27, wherein a number of the antenna port is determined by the following equation:

Antenna port index=A starting antenna port index of the set of antenna ports+function(the time and frequency resource)+offset value indicated by the offset parameter.

30. The method of claim 29, wherein the offset parameter has a value of zero if the E-PDCCH is received over one eCCE

31. The method of claim 29, wherein the function is given by the following equation:

function(the time and frequency resource)=(index of the first eCCE of the time and frequency resource)mod(number eCCEs per PRB pair)

wherein x mod(N) is a modulo N operation on x.

32. The method of claim 29, wherein the offset parameter is semi-statically signaled by an enhanced node B (eNB) to the UE through radio resource control (RRC) signaling.

33. The method of claim 29, wherein the offset parameter is a function of the UE'"'"'s radio network temporary identifier (RNTI).

34. The method of claim 33, wherein the function is a modulo two function.

35. The method of claim 29, wherein the offset parameter is a function of both the UE'"'"'s RNTI and the subframe number over which the E-PDCCH is to be received.

36. The method of claim 35, wherein the function is given by the following equation:

Offset parameter at subframe k=Y_k mod(2)

wherein Y_k=(A·

Y<sub>k−

1</sub>)mod D, Y<sub>k−

1</sub>=n_RNTI, A=39827, D=65537, n_RNTI is the value of RNTI.