Enhanced PHICH transmission for LTE-advanced

• US 9,998,268 B2
• Filed: 12/14/2015
• Issued: 06/12/2018
• Est. Priority Date: 03/06/2012
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Heo, Youn Hyoung, Gao, Shiwei, Xu, Hua, Blankenship, Yufei Wu, Jia, Yongkang
• Primary Examiner(s): HOANG, THAI D
• Application Number:
  US14/968,554
• Publication Number:
  US 20160105266A1
• Time in Patent Office: 911 Days
• Field of Search: 370203-208, 370312, 370329-330, 370335-336, 370342-345, 455101, 4554221-425, 455450, 455 17, 455500, 455509, 375260
• CPC Class Codes: H04L 1/0038 Blind format detection for detection of modulation format H04L27/0012
• CPC Class Codes: H04L 1/1829 Arrangements specially adapted for the receiver end
• CPC Class Codes: H04L 1/1858 Transmission or retransmission of more than one copy of acknowledgement message
• CPC Class Codes: H04L 1/1861 Physical mapping arrangements for ACK signaling see also H04L5/0053
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated

Abstract

A method is provided for communication in a wireless telecommunication system. The method comprises generating a sequence of signals of an enhanced physical HARQ (hybrid automatic repeat request) indicator channel (E-PHICH). The method further comprises mapping the sequence of signals of the E-PHICH to a first set of resource elements, wherein the first set of resource elements is multiplexed with a second set of resource elements over a set of virtual resource blocks, and wherein the second set of resource elements carries at least one of an enhanced physical downlink control channel (E-PDCCH) and a physical downlink shared channel (PDSCH).

Claims

1. A method for communication in a wireless telecommunication system, the method comprising:

monitoring, by a user equipment (UE), both a physical hybrid automatic repeat request (HARQ) indicator channel (PHICH) and an enhanced PHICH (E-PHICH) transmitted by a network element; and

determining, by the UE, whether the PHICH or the E-PHICH is being used to assign resources, wherein the UE determines whether the PHICH or the E-PHICH is being used based on a number of PHICH groups and a number of E-PHICH groups, wherein the number of PHICH groups is indicated in a physical broadcast channel (PBCH), and wherein the number of E-PHICH groups is indicated via one of higher layer signaling or in unused bits within the PBCH.

2. The method of claim 1, further comprising:

comparing, by the UE, the number of PHICH groups with the number of E-PHICH groups; and

determining, by the UE, that the E-PHICH is being used to assign resources if the number of PHICH groups is greater than or equal to the number of E-PHICH groups.

3. The method of claim 1, further comprising determining, by the UE, whether the PHICH or the E-PHICH is being used depending on whether a physical uplink shared channel (PUSCH) physical resource block (PRB) index and a demodulation reference signal (DMRS) value satisfy certain criteria.

4. The method of claim 1, further comprising monitoring, by the UE, both the PHICH and the E-PHICH in a downlink subframe.

5. The method of claim 1, further comprising monitoring, by the UE, only the E-PHICH in a downlink subframe where the PHICH is not monitored.

6. The method of claim 1, further comprising receiving, by the UE, UE-specific radio resource control (RRC) signaling from the network element that directs the UE to receive an acknowledgement/negative acknowledgement (ACK/NACK) only via the E-PHICH, wherein the UE-specific RRC signaling carries resource allocation information for the E-PHICH, and wherein the UE-specific RRC signaling triggers the UE to receive a downlink control channel via an enhanced physical downlink control channel (E-PDCCH).

7. The method of claim 1, further comprising:

receiving, by the UE, UE-specific radio resource control (RRC) signaling from the network element that directs the UE to stop monitoring the E-PHICH; and

monitoring, by the UE, only the PHICH in response to receiving the UE-specific RRC signaling.

8. A user equipment (UE) comprising:

at least one memory device; and

a processor configured to execute instructions stored on the at least one memory device such that when executed, the UE;

monitors both a physical hybrid automatic repeat request (HARQ) indicator channel (PHICH) and an enhanced PHICH (E-PHICH) transmitted by a network element;

determines whether the PHICH or the E-PHICH is being used to assign resources; and

monitors only the PHICH or the E-PHICH in response to receiving signaling that directs the UE to stop monitoring the E-PHICH or the PHICH, respectively.

9. The UE of claim 8, wherein the UE determines whether the PHICH or the E-PHICH is being used based at least on a physical uplink shared channel (PUSCH) physical resource block (PRB) index.

10. The UE of claim 9, wherein all PHICH and E-PHICH resources are jointly mapped to the PUSCH PRB index.

11. The UE of claim 8, wherein the PHICH is used when an uplink downlink control information (DCI) grant is transmitted on a physical downlink control channel (PDCCH), and wherein the E-PHICH is used when the uplink DCI grant is transmitted on an enhanced PDCCH (E-PDCCH).

12. The UE of claim 11, wherein:

when the uplink DCI grant is transmitted on the PDCCH, the UE calculates a PHICH group index using the following formula;

n_PHICH^group=(I_{PRB_RA}^lowest_index+n_DMRS)mod N_PHICH^group+I_PHICHN_PHICH^group;

and

n_PHICH^seq=(└

I_{PRB_RA}^lowest_index/N_PHICH^group┘

+n_DMRS)mod2N_SF^PHICH

when the uplink DCI grant is transmitted on the E-PDCCH, the UE calculates the PHICH group index using the following formula;

n_E-PHICH^group=(I_{PRB_RA}^lowest_index+n_DMRS)mod N_E-PHICH^group+I_PHICHN_E-PHICH^group

n_E-PHICH^seq=(└

I_{PRB_RA}^lowest_index/N_E-PHICH^group┘

+n_DMRS)mod 2N_SF^PHICH.

13. The UE of claim 8, wherein, when the UE is configured to decode the E-PHICH, the UE derives an E-PHICH group number and a sequence index using the following formula:

n_E-PHICH^group=(I_{PRB_RA}^lowest_index+n_DMRS)modN_E-PHICH^group+I_PHICHN_E-PHICH^group

n_E-PHICH^seq=(└

I_{PRB_RA}^lowest_index/N_E-PHICH^group┘

+n_DMRS)mod 2N_E-SF^PHICH.

14. The UE of claim 8, wherein the UE monitors a downlink acknowledgement/negative acknowledgement (ACK/NACK) response only via the PHICH in a legacy control region when the UE initially attaches to the network element.

15. The UE of claim 8, wherein a resource set of the E-PHICH in a subframe relates to a variable sent to a plurality of UEs by the network element.

16. The UE of claim 15, wherein a first value of the variable indicates that the resource set resides in a first slot of a subframe only, and a second value of the variable indicates that the resource set spans a first slot and a second slot of a subframe.

17. The UE of claim 8, wherein the PHICH is used to carry a HARQ-ACK response when a related uplink downlink control information (DCI) grant is transmitted on a physical downlink control channel (PDCCH), and the E-PHICH is used to carry the HARQ-ACK response when a related uplink DCI grant is transmitted on an enhanced PDCCH (E-PDCCH).

18. The UE of claim 8, wherein a resource set of the E-PHICH is defined independently of a resource set of the PHICH.

19. The UE of claim 8, wherein:

when the network element adds the second component carrier to the UE as a secondary cell, the UE starts to receive HARQ-ACK responses related to uplink data transmission on the second component carrier via a downlink channel of the second component carrier, wherein the network element configures the E-PHICH on the second component carrier before the second component carrier is added as a secondary cell; and

when the network element removes the second component carrier from the UE'"'"'s secondary cell list, the UE switches to receiving HARQ-ACK response uplink data transmission on the second component carrier via a downlink channel of the first component carrier.

20. A non-transitory computer medium storing computer readable instructions executable by a processor to implement a method for communication in a wireless telecommunication system, the method comprising:

monitoring, by a user equipment (UE), both a physical hybrid automatic repeat request (HARQ) indicator channel (PHICH) and an enhanced PHICH (E-PHICH) transmitted by a network element;

determining, by the UE, whether the PHICH or the E-PHICH is being used to assign resources; and

monitoring, by the UE, only the PHICH or the E-PHICH in response to receiving signaling that directs the UE to stop monitoring the E-PHICH or the PHICH, respectively.