Enhanced PDCCH with transmit diversity in LTE systems

• US 8,842,628 B2
• Filed: 09/11/2012
• Issued: 09/23/2014
• Est. Priority Date: 09/12/2011
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Gao, Shiwei, Xu, Hua, Jia, Yongkang, Mobasher, Amin
• Primary Examiner(s): MARCELO, MELVIN C
• Application Number:
  US13/610,396
• Publication Number:
  US 20130064215A1
• Time in Patent Office: 742 Days
• Field of Search: 370/329, 370/330
• US Class Current: 370/329
• 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 communication in a wireless telecommunications network. The method comprises transmitting an extended physical downlink control channel to a user equipment using transmit diversity from at least one demodulation reference signal port.

Claims

1. A method for communication in a wireless telecommunications network, comprising:

transmitting an extended physical downlink control channel (E-PDCCH) to a user equipment (UE) using transmit diversity from at least one demodulation reference signal (DMRS) port.

2. The method of claim 1, wherein the DMRS port uses the same set of resource elements to carry a reference signal as those DMRS ports defined in Release 10 of the Third Generation Partnership Project Long Term Evolution standards.

3. The method of claim 1, wherein the transmit diversity is at least one of:

space-frequency block code (SFBC);

hybrid SFBC and space-time block code (STBC);

or

channel independent beamforming.

4. The method of claim 3, wherein channel independent beamforming is achieved by applying a precoding operation on modulated E-PDCCH symbols before the modulated E-PDCCH symbols are transmitted over at least two antennas, and wherein the precoding operation comprises applying one precoding vector to a modulated E-PDCCH symbol.

5. The method of claim 4, wherein different precoding vectors are used for different modulated symbols or different groups of modulated symbols of the E-PDCCH in a physical resource block pair.

6. The method of claim 5, wherein the different groups of modulated symbols of the E-PDCCH are transmitted on different DMRS ports.

7. The method of claim 1, wherein transmission using transmit diversity is assumed for an E-PDCCH transmission when at least two DMRS ports are configured in a physical resource block pair for the E-PDCCH.

8. The method of claim 1, wherein the use of transmit diversity for an E-PDCCH transmission is explicitly signaled to the UE.

9. The method of claim 1, wherein modulated symbols of the E-PDCCH are mapped to resource elements in at least one physical resource block pair using at least one of:

space frequency block code (SFBC)-based mapping;

hybrid SFBC and space time block code (STBC)-based mapping;

or

symbol-by-symbol based mapping to a time-and-frequency resource following a pre-defined rule for channel independent beamforming.

10. The method of claim 1, wherein, when the UE is within the coverage areas of at least two transmission points, an E-PDCCH is transmitted from at least two of the transmission points using at least one of:

transmit diversity;

beamforming;

or

combined transmit diversity and beamforming.

11. An access node in a wireless telecommunications network, comprising:

a processor configured such that the access node transmits an extended physical downlink control channel (E-PDCCH) to a user equipment (UE) using transmit diversity from at least one demodulation reference signal (DMRS) port.

12. The access node of claim 11, wherein the DMRS port uses the same set of resource elements to carry a reference signal as those DMRS ports defined in Release 10 of the Third Generation Partnership Project Long Term Evolution standards.

13. The access node of claim 11, wherein the transmit diversity is at least one of:

space-frequency block code (SFBC);

hybrid SFBC and space-time block code (STBC);

or

channel independent beamforming.

14. The access node of claim 13, wherein channel independent beamforming is achieved by applying a precoding operation on modulated E-PDCCH symbols before the modulated E-PDCCH symbols are transmitted over at least two antennas, and wherein the precoding operation comprises applying one precoding vector to a modulated E-PDCCH symbol.

15. The access node of claim 14, wherein different precoding vectors are used for different modulated symbols or different groups of modulated symbols of the E-PDCCH in a physical resource block pair.

16. The access node of claim 15, wherein the different groups of modulated symbols of the E-PDCCH are transmitted on different DMRS ports.

17. The access node of claim 11, wherein transmission using transmit diversity is assumed for an E-PDCCH transmission when at least two DMRS ports are configured in a physical resource block pair for the E-PDCCH.

18. The access node of claim 11, wherein the use of transmit diversity for an E-PDCCH transmission is explicitly signaled to the UE.

19. The access node of claim 11, wherein modulated symbols of the E-PDCCH are mapped to resource elements in at least one physical resource block pair using at least one of:

space frequency block code (SFBC)-based mapping;

hybrid SFBC and space time block code (STBC)-based mapping;

or

symbol-by-symbol based mapping to a time-and-frequency resource following a pre-defined rule for channel independent beamforming.

20. The access node of claim 11, wherein, when the UE is within the coverage areas of at least two transmission points, an E-PDCCH is transmitted from at least two of the transmission points using at least one of:

transmit diversity;

beamforming;

or

combined transmit diversity and beamforming.

21. A user equipment (UE), comprising:

a processor configured such that the UE receives an extended physical downlink control channel (E-PDCCH) that was transmitted using transmit diversity from at least one demodulation reference signal (DMRS) port.

22. The UE of claim 21, wherein the DMRS port uses the same set of resource elements to carry a reference signal as those DMRS ports defined in Release 10 of the Third Generation Partnership Project Long Term Evolution standards.

23. The UE of claim 21, wherein the transmit diversity is at least one of:

space-frequency block code (SFBC);

hybrid SFBC and space-time block code (STBC);

or

channel independent beamforming.

24. The UE of claim 23, wherein, in the case of channel independent beamforming, the UE receives different modulated symbols or different groups of modulated symbols of the E-PDCCH in a physical resource block pair associated with different DMRS ports.

25. The UE of claim 21, wherein transmit diversity is assumed for an E-PDCCH reception when at least two DMRS ports are configured in a physical resource block pair for the E-PDCCH.

26. The UE of claim 21, wherein the use of transmit diversity for an E-PDCCH transmission is explicitly signaled to the UE.

27. The UE of claim 21, wherein modulated symbols of the E-PDCCH are mapped to resource elements in at least one physical resource block pair using at least one of:

space frequency block code (SFBC)-based mapping;

hybrid SFBC and space time block code (STBC)-based mapping;

or

symbol-by-symbol based mapping to a time-and-frequency resource following a pre-defined rule for channel independent beamforming.

28. The UE of claim 21, wherein, when the UE is within the coverage areas of at least two transmission points, the UE receives the E-PDCCH from at least two of the transmission points, the E-PDCCH having been transmitting using at least one of:

transmit diversity;

beamforming;

or

combined transmit diversity and beamforming.