Physical uplink control channel (PUCCH) resource allocation (RA) for a hybrid automatic retransmission re-quest-acknowledge (HARQ-ACK) transmission

• US 9,397,945 B2
• Filed: 06/27/2013
• Issued: 07/19/2016
• Est. Priority Date: 10/26/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Han, Seunghee, Zhu, Yuan, Fwu, Jong-Kae, Chen, Xiaogang
• Primary Examiner(s): Zhu, Alvin
• Application Number:
  US14/125,325
• Publication Number:
  US 20150016311A1
• Time in Patent Office: 1,118 Days
• US Class Current: 1/1
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04L 1/1861 Physical mapping arrangements for ACK signaling see also H04L5/0053
• CPC Class Codes: H04L 12/1407 Policy-and-charging control [PCC] architecture
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 47/38 by adapting coding or compression rate
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 28/0289 Congestion control load shedding arrangements in network planning H04W16/08; performing reselection for handling the traffic H04W36/22; wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Technology to provide conditional physical uplink control channel (PUCCH) resource allocation in time division duplex (TDD) for a hybrid automatic retransmission request-acknowledge (HARQ-ACK) transmission in a subframe n is disclosed. In an example, a user equipment (UE) can include computer circuitry configured to: Receive a downlink control channel within a prior specified subframe, wherein the prior specified subframe occurs in time before the subframe n; recognize a downlink control channel type received within the prior specified subframe is a physical downlink control channel (PDCCH) or an enhanced physical downlink control channel (EPDCCH); determine a PUCCH resource for the HARQ-ACK transmission using a lowest control channel element (CCE) index of the PDCCH when the received downlink control channel type is the PDCCH; and determine the PUCCH resource for the HARQ-ACK transmission using a lowest enhanced CCE (ECCE) index of the EPDCCH when the received downlink control channel type is the EPDCCH.

Claims

1. A user equipment (UE) operable to provide conditional physical uplink control channel (PUCCH) resource allocation in time division duplex (TDD) for a hybrid automatic retransmission re-quest-acknowledge (HARQ-ACK) transmission in a subframe n, having computer circuitry configured to:

receive a downlink control channel within a prior specified subframe, wherein the prior specified subframe occurs in time before the subframe n;

recognize that a downlink control channel type received within the prior specified subframe is a physical downlink control channel (PDCCH) or an enhanced physical downlink control channel (EPDCCH);

determine a PUCCH resource for the HARQ-ACK transmission using a lowest control channel element (CCE) index of the PDCCH when the received downlink control channel type is the PDCCH; and

determine the PUCCH resource for the HARQ-ACK transmission using a lowest enhanced CCE (ECCE) index of the EPDCCH when the received downlink control channel type is the EPDCCH,

wherein the prior specified subframe includes a subframe n−

k, where kε

K, where a downlink association set index K is defined in a Table 10.1.3.1-1 in a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard Release 11 Technical Specification (TS) 36.213, and K includes a set of M elements {k₀, k₁, . . . , k<sub>M−

1</sub>} depending on the subframe n and an uplink/downlink (UL/DL) configuration,

wherein computer circuitry configured to determine the PUCCH resource using the lowest ECCE index of the EPDCCH is further configured to determine the PUCCH resource for the subframe n−

k using a parameter, wherein the parameter is derived from an acknowledgement (ACK)/negative ACK (ACK/NACK) Resource Offset (ARO), and antenna port (AP), a UE specific starting offset value for an EPDCCH set, and an integer m, where a k_m is the smallest value in a set K such that the UE detects an EPDCCH in a subframe n−

k_m.

2. The computer circuitry of claim 1, wherein the subframe n−

k includes a PDCCH and a configured EPDCCH subframe.

3. The computer circuitry of claim 1, wherein for one configured serving cell and the subframe n, with M=1 where M is a number of elements in the set Kε

{k₀, k₁, . . . k<sub>M−

1</sub>};

computer circuitry configured to determine the PUCCH resource n_PUCCH^{(1,{tilde over (p)})} for a HARQ-ACK transmission using the lowest CCE index n_CCE of the PDCCH selects a c value out of {0, 1, 2, 3} which makes N_c≦

n_CCE<

N_c+1 and uses the PUCCH resource n_PUCCH^{(1,{tilde over (p)})} represented by n_PUCCH^{(1,{tilde over (p)}0)}=(M−

m−

1)·

N_c+m·

N_c+1+n_CCE+N_PUCCH⁽¹⁾ for antenna port p₀ and n_PUCCH^{(1,{tilde over (p)}1)}=(M−

m−

1)·

N_c+m·

N_c+1+n_CCE+N_PUCCH⁽¹⁾ for antenna port p₁, where n_CCE is a first CCE index number used for transmission of a corresponding PDCCH in subframe n−

k_m and the corresponding m, where k_m is the smallest value in set K such that UE detects a PDCCH in subframe n−

k_m, N_c=max{0,└

[N_RB^DL·

(N_sc^RB·

c−

4)]/36┘

}, N_RB^DL is a downlink bandwidth configuration, expressed in units of N_sc^RB, N_sc^RB a resource block size in the frequency domain, expressed as a number of subcarriers, and N_PUCCH⁽¹⁾ is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE, and antenna port p₁ is used when two antenna port transmission is configured; and

computer circuitry configured to determine the PUCCH resource n_PUCCH^{(1,{tilde over (p)})} for the HARQ-ACK transmission using the lowest ECCE index n_ECCE of the EPDCCH uses the PUCCH resource n_PUCCH^{(1,{tilde over (p)})} represented by n_PUCCH^{(l,{tilde over (p)}0)}=n_ECCE+Value for antenna port p₀ and n_PUCCH^{(l,{tilde over (p)}1)}=n_ECCE+Value+1 for antenna port p₁, where Value is the parameter, n_ECCE is the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−

k_m and a corresponding m, where k_m is the smallest value in set K such that UE detects an EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−

k_m, and antenna port p₁ is used when two antenna port transmission is configured.

4. The computer circuitry of claim 1, wherein for one configured serving cell and a subframe n with M>

1 where M is the number of elements in the set Kε

{k₀, k₁, . . . k<sub>M−

1</sub>} and 0≦

i≦

M−

1;

computer circuitry configured to determine the PUCCH resource n_PUCCH,i⁽¹⁾ for a HARQ-ACK transmission using the lowest CCE index n_CCE,i is represented by n_PUCCH,i⁽¹⁾=(M−

i−

1)·

N_c+i·

N_c+1+n_CCE,i+N_PUCCH⁽¹⁾, where c is selected from {0, 1, 2, 3} such that N_c≦

n_CCE,i<

N_c+1, n_CCE,i is a first CCE index number used for transmission of a corresponding PDCCH in subframe n−

k_i, N_c=max{0,└

[N_RB^DL·

(N_sc^RB·

c−

4)]/36┘

}, N_RB^DL is a downlink bandwidth configuration, expressed in units of N_sc^RB, N_sc^RB a resource block size in the frequency domain, expressed as a number of subcarriers, and N_PUCCH⁽¹⁾ is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE; and

computer circuitry configured to determine the PUCCH resource n_PUCCH,i⁽¹⁾ for the HARQ-ACK transmission using the lowest ECCE index n_ECCE,i is represented by n_PUCCH,i⁽¹⁾=n_ECCE,i+Value, where Value is the parameter, n_ECCE,i is the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−

k_i.

5. The computer circuitry of claim 1, wherein for at least two configured serving cells and a subframe n with M≦

2 where M is the number of elements in the set Kε

{k₀, k₁, . . . k<sub>M−

1</sub>}, k_m ε

K on a primary cell, and 0≦

j≦

A−

1 and Aε

{2, 3, 4};

computer circuitry configured to determine the PUCCH resource n_PUCCH,j⁽¹⁾ for a HARQ-ACK transmission using the lowest CCE index n_CCE,m is represented by n_PUCCH,j⁽¹⁾=(M−

m−

1)·

N_c+m·

N_c+1+n_CCE,m+N_PUCCH⁽¹⁾ and n_PUCCH,j+1⁽¹⁾=(M−

m−

1)·

N_c+m·

N_c+1+n_CCE,m+1+N_PUCCH⁽¹⁾, where c is selected from {0, 1, 2, 3} such that N_c≦

n_CCE,m<

N_c+1, n_CCE,m is a first CCE index number used for transmission of a corresponding PDCCH in subframe n−

k_m, N_c=max{0,└

[N_RB^DL·

(N_sc^RB·

c−

4)]/36┘

}, N_RB^DL is a downlink bandwidth configuration from the primary cell, expressed in units of N_sc^RB/N_sc^RB a resource block size in the frequency domain, expressed as a number of subcarriers, and N_PUCCH⁽¹⁾ is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE, and n_PUCCH,j+1⁽¹⁾ is used for a subframe n and a transmission mode that support up to two transport block on a serving cell where a corresponding physical downlink shared channel (PDSCH) transmission occurs; and

computer circuitry configured to determine the PUCCH resource n_PUCCH,j⁽¹⁾ for the HARQ-ACK transmission using the lowest ECCE index n_ECCE,m is represented by n_PUCCH,j⁽¹⁾=n_ECCE,m+Value and n_PUCCH,j+1⁽¹⁾=n_ECCE,m+Value+1, where Value is the parameter, n_ECCE,m is the number of the first ECCE used for transmission of the corresponding DCI assignment by EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−

k_m, and n_PUCCH,j+1⁽¹⁾ is used for a subframe n and a transmission mode that support up to two transport block on a serving cell where a corresponding PDSCH transmission occurs.

6. The computer circuitry of claim 1, wherein for at least two configured serving cells and a subframe n with M>

2 where M is the number of elements in the set Kε

{k₀, k₁, . . . k<sub>M−

1</sub>}, kε

K, k_m ε

K for a primary cell;

computer circuitry configured to determine the PUCCH resource n_PUCCH,1⁽¹⁾ for a HARQ-ACK transmission using the lowest CCE index n_CCE,m is represented by n_PUCCH,1⁽¹⁾=(M−

m−

1)·

N_c+m·

N_c+1+n_CCE+N_PUCCH⁽¹⁾, where c is selected from {0, 1, 2, 3} such that N_c≦

n_CCE,m<

N_c+1, n_CCE,m is a first CCE index number used for transmission of a corresponding PDCCH in subframe n−

k_m, N_c=max{0,└

[N_RB^DL·

(N_sc^RB·

c−

4)]/36┘

}, N_RB^DL is a downlink bandwidth configuration from the primary cell, expressed in units of N_sc^RB/N_sc^RB a resource block size in the frequency domain, expressed as a number of subcarriers, and N_PUCCH⁽¹⁾ is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE; and

computer circuitry configured to determine the PUCCH resource n_PUCCH,1⁽¹⁾ for the HARQ-ACK transmission using the lowest ECCE index n_ECCE,m is represented by n_PUCCH,1⁽¹⁾=n_ECCE,m+Value, where Value is the parameter, n_ECCE,m is the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−

k_m.

7. The computer circuitry of claim 1, wherein the computer circuitry uses the PUCCH resource n_PUCCH^{({tilde over (p)})} for the HARQ-ACK transmission in a subframe n for a {tilde over (p)} mapped to an antenna port p for a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard Release 11 PUCCH format 1a or 1b, or 3GPP PUCCH LTE standard Release 11 format 1b with channel selection, or 3GPP PUCCH LTE standard Release 11 format 3.

8. The computer circuitry of claim 1, wherein the UE includes an antenna, a touch sensitive display screen, a speaker, a microphone, a graphics processor, an application processor, internal memory, or a non-volatile memory port.

9. A method for conditional time division duplex (TDD) physical uplink control channel (PUCCH) resource allocation for a hybrid automatic retransmission re-quest-acknowledge (HARQ-ACK) transmission in a subframe n at a user equipment (UE), comprising:

recognizing that a downlink control channel type received within a prior specified subframe is a physical downlink control channel (PDCCH) or an enhanced physical downlink control channel (EPDCCH), wherein the prior specified subframe occurs in time before the subframe n;

determining a PUCCH resource for the HARQ-ACK transmission using a lowest control channel element (CCE) index of a physical downlink control channel (PDCCH) when the downlink control channel type is the PDCCH; and

determining the PUCCH resource for the HARQ-ACK transmission using a lowest enhanced CCE (ECCE) index of the EPDCCH when the downlink control channel type is the EPDCCH,

wherein the prior specified subframe includes a subframe n−

k, where kε

K, where a downlink association set index K is defined in a Table 10.1.3.1-1 in a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard Release 11 Technical Specification (TS) 36.213, and K includes a set of M elements {k₀, k₁, . . . , k<sub>M−

1</sub>} depending on the subframe n and an uplink/downlink (UL/DL) configuration,

wherein determining the PUCCH resource using the lowest enhanced CCE (ECCE) index of the EPDCCH further comprises determining the PUCCH resource for the subframe n−

k using a parameter Value represent by Value=ARO+AP+(m+1)·

N_PUCCH^(1,k) where acknowledgement (ACK)/negative ACK (ACK/NACK) Resource Offset (ARO) is an integer offset value derived from a downlink control information (DCI) in the EPDCCH, an antenna port (AP) is parameter (0, . . . ,

     3), a N_PUCCH^(1,k) is a UE specific starting offset value for an EPDCCH set {tilde over (k)}, and m is an integer, where k_m is the smallest value in a set K such that the UE detects an EPDCCH for an EPDCCH set {tilde over (k)} in a subframe n−

k_m.

10. The method of claim 9, wherein for one configured serving cell and the subframe n with M=1:

determining the PUCCH resource n_PUCCH^{(1,{tilde over (p)})} for a HARQ-ACK transmission using the lowest CCE index n_CCE of the PDCCH further comprises selecting a c value out of {0, 1, 2, 3} which makes N_c≦

n_CCE<

N_c+1 and using the PUCCH resource n_PUCCH^{(1,{tilde over (p)})} represented by n_PUCCH^{(1,{tilde over (p)})}=(M−

m−

1)·

N_c+m·

N_c+1+n_CCE+N_PUCCH⁽¹⁾ for antenna port p₀ and n_PUCCH^{(1,{tilde over (p)})}=(M−

m−

1)·

N_c+m·

N_c+1+n_CCE+N_PUCCH⁽¹⁾ for antenna port p₁, where n_CCE is a first CCE index number used for transmission of a corresponding PDCCH in subframe n−

k_m and the corresponding m, where k_m is the smallest value in set K such that UE detects a PDCCH in subframe n−

k_m, N_c=max{0,└

[N_RB^DL·

(N_sc^RB·

c−

4)]/36┘

}, N_RB^DL is a downlink bandwidth configuration, expressed in units of N_sc^RB/N_sc^RB a resource block size in the frequency domain, expressed as a number of subcarriers, and N_PUCCH⁽¹⁾ is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE, wherein antenna port p₁ is used when two antenna port transmission is configured; and

determining the PUCCH resource n_PUCCH^{(1,{tilde over (p)})} for the HARQ-ACK transmission using the lowest ECCE index n_ECCE of the EPDCCH further comprises using the PUCCH resource n_PUCCH^{(1,{tilde over (p)})} PUCCH represented by n_PUCCH^{(1,{tilde over (p)}0)}=n_ECCE+Value for antenna port p₀ and n_PUCCH^{(1,{tilde over (p)}1)}=n_ECCE+Value+1 for antenna port p₁, where n_ECCE is the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−

k_m and a corresponding m, where k_m is the smallest value in set K such that UE detects an EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−

k_m, and antenna port p₁ is used when two antenna port transmission is configured.

11. The method of claim 9, wherein for one configured serving cell and the subframe n with M>

1 where 0≦

i≦

M−

1;

determining the PUCCH resource n_PUCCH,i⁽¹⁾ for a HARQ-ACK transmission using the lowest CCE index n_CCE,i is represented by n_PUCCH,i⁽¹⁾=(M−

i−

1)·

N_c+i·

N_c+1+n_CCE,i+N_PUCCH⁽¹⁾, where c is selected from {0, 1, 2, 3} such that N_c≦

n_CCE,i<

N_c+1, n_CCE,i is a first CCE index number used for transmission of a corresponding PDCCH in subframe n−

k_i, N_c=max{0,└

[N_RB^DL·

(N_sc^RB·

c−

4)]/36┘

}, N_RB^DL is a downlink bandwidth configuration, expressed in units of N_sc^RB/N_sc^RB a resource block size in the frequency domain, expressed as a number of subcarriers, and N_PUCCH⁽¹⁾ is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE; and

determining the PUCCH resource n_PUCCH,i⁽¹⁾ for the HARQ-ACK transmission using the lowest ECCE index n_ECCE,i is represented by n_PUCCH,i⁽¹⁾=n_ECCE,i+Value, where n_ECCE,i is the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−

k_i.

12. The method of claim 9, wherein for at least two configured serving cells and a subframe n with M≦

2 where k_m ε

K on a primary cell, and 0≦

j≦

A−

1 and Aε

{2, 3, 4};

determining the PUCCH resource n_PUCCH,j⁽¹⁾ for a HARQ-ACK transmission using the lowest CCE index n_CCE,m is represented by n_PUCCH,j⁽¹⁾(M−

m−

1)·

N_c+m·

N_c+1+n_CCE,m+N_PUCCH⁽¹⁾ and n_PUCCH,j+1⁽¹⁾(M−

m−

1)·

N_c+m·

N_c+1+n_CCE,m+N_PUCCH⁽¹⁾, where C is selected from {0, 1, 2, 3} such that N_c≦

n_CCE,m<

N_c+1, n_CCE,m is a first CCE index number used for transmission of a corresponding PDCCH in subframe n−

k_i, N_c=max{0,└

[N_RB^DL·

(N_sc^RB·

c−

4)]/36┘

}, N_RB^DL is a downlink bandwidth configuration from the primary cell, expressed in units of N_sc^RB, N_sc^RB a resource block size in the frequency domain, expressed as a number of subcarriers, and N_PUCCH⁽¹⁾ is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE, wherein n_PUCCH,j+1⁽¹⁾ is used for a subframe n and a transmission mode that support up to two transport block on a serving cell where a corresponding physical downlink shared channel (PDSCH) transmission occurs; and

determining the PUCCH resource n_PUCCH,j⁽¹⁾ for the HARQ-ACK transmission using the lowest ECCE index n_ECCE,m is represented by n_PUCCH,j⁽¹⁾=n_ECCE,m+Value and n_PUCCH,j+1⁽¹⁾=n_ECCE,m+Value+1, where n_ECCE,m is the number of the first ECCE used for transmission of the corresponding DCI assignment by EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−

k_m, and n_PUCCH,j+1⁽¹⁾ is used for a subframe n and a transmission mode that support up to two transport block on a serving cell where a corresponding PDSCH transmission occurs.

13. The method of claim 9, wherein for at least two configured serving cells and a subframe n with M>

2 where kε

K, k_m ε

K for a primary cell;

determining the PUCCH resource n_PUCCH,1⁽¹⁾ PUCCH for a HARQ-ACK transmission using the lowest CCE index n_CCE,m is represented by n_PUCCH,1⁽¹⁾=(M−

m−

1)·

N_c+m·

N_c+1+n_CCE,m+N_PUCCH⁽¹⁾, where c is selected from {0, 1, 2, 3} such that N_c≦

n_CCE,m<

N_c+1, n_CCE,m is a first CCE index number used for transmission of a corresponding PDCCH in subframe n−

k_m, N_c=max{0,└

[N_RB^DL·

(N_sc^RB·

c−

4)]/36┘

}, N_RB^DL is a downlink bandwidth configuration from the primary cell, expressed in units of N_sc^RB/N_sc^RB a resource block size in the frequency domain, expressed as a number of subcarriers, and N_PUCCH⁽¹⁾ is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE; and

determining the PUCCH resource n_PUCCH,1⁽¹⁾ for the HARQ-ACK transmission using the lowest ECCE index n_ECCE,m is represented by n_PUCCH,1⁽¹⁾=n_ECCE,m+Value, where n_ECCE,m is the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−

k_m.

14. At least one non-transitory machine readable storage medium comprising a plurality of instructions adapted to be executed to implement the method of claim 9.

15. A device at a node configured to detect a physical uplink control channel (PUCCH) resource allocation in time division duplex (TDD) for a hybrid automatic retransmission re-quest-acknowledge (HARQ-ACK) transmission in a subframe n, comprising:

a transceiver to receive a PUCCH resource in a subframe n configured with a downlink control channel type; and

a processor to;

determine when the subframe n is configured with a physical downlink control channel (PDCCH) or an enhanced physical downlink control channel (EPDCCH),

decode the PUCCH resource for a HARQ-ACK transmission using a lowest control channel element (CCE) index of a physical downlink control channel (PDCCH) when the downlink control channel type is the PDCCH, and

decode the PUCCH resource for the HARQ-ACK transmission using a lowest enhanced CCE (ECCE) index of an EPDCCH when the downlink control channel type is the EPDCCH,

wherein the downlink control channel type is received in a subframe n−

k, where kε

K, where a downlink association set index K is defined in a Table 10.1.3.1-1 in a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard Release 11 Technical Specification (TS) 36.213, and K includes a set of M elements {k₀, k₁, . . . K<sub>M−

1</sub>} depending on the subframe n and a uplink/downlink (UL/DL) configuration,

wherein the processor configured to decode the PUCCH resource for the HARQ-ACK transmission using the lowest ECCE index of the EPDCCH is further configured to decode the PUCCH resource using a parameter Value represent by Value=ARO+AP+(m+1)·

N_PUCCH^(1,k) where acknowledgement (ACK)/negative ACK (ACK/NACK) Resource Offset (ARO) is an integer offset value derived from a downlink control information (DCI) in the EPDCCH, an antenna port (AP) is parameter (0, . . . ,

     3), a N_PUCCH^(1,k) is a UE specific starting offset value for an EPDCCH set {tilde over (k)}, and m is an integer, where k_m is the smallest value in a set K such that the UE detects an UPDCCH for an EPDCCH set {tilde over (k)} in subframe n−

k_m.

16. The device of claim 15, wherein the node is selected from the group consisting of a base station (BS), a Node B (NB), an evolved Node B (eNB), a baseband unit (BBU), a remote radio head (RRH), a remote radio equipment (RRE), a remote radio unit (RRU), and a central processing module (CPM).