Uplink control channel resource mapping for an enhanced PDCCH in LTE systems

1. A method for operating a UE (user equipment) in an LTE (Long Term Evolution) network using TDD (time division duplex) mode, comprising:

receiving transmitted downlink resource allocations from an eNB (evolved Node B) in an enhanced physical downlink control channel (ePDCCH) made up of one or more indexed enhanced control channel elements (eCCEs) contained within indexed physical resource blocks (PRBs);

transmitting a hybrid-ARQ acknowledgement corresponding to a detected ePDCCH allocating physical downlink shared channel (PDSCH) resources via a physical uplink control channel (PUCCH) resource that is implicitly indicated by the detected ePDCCH; and,

wherein the ePDCCH is detected in a downlink subframe belonging to a specified bundling window of M indexed downlink subframes and wherein the PUCCH resource is defined by a PUCCH resource index n PUCCH,i (1) and further comprising, for each subframe in the bundling window having an ePDCCH allocating downlink resources, calculating the PUCCH resource index n PUCCH,i (1) such that consecutive PUCCH resource indices are mapped to by the ePDCCHs ordered in accordance with an ordered list of the eCCEs making up the ePDCCHs where the eCCEs are: 1) ordered first according to subframe index, then according to PRB index, and then according to eCCE index, 2) ordered first according to PRB index, then according to subframe index, and then according to eCCE index, 3) ordered first according to slot number within the subframe, then according to subframe index, then according to PRB index, and then according to eCCE index, 4) ordered first according to PRB index, then according to slot number within the subframe, then according to subframe index, and then according to eCCE index, or 5) ordered first according to PRB index, then according to eCCE index, then according to subframe index.

2. The method of claim 1 wherein the ePDCCH is detected in a downlink subframe belonging to a specified bundling window of M indexed downlink subframes and wherein the PUCCH resource is defined by a PUCCH resource index n PUCCH,i (1) that is a function of subframe index, lowest index of a PRB containing at least one eCCE in the detected ePDCCH, and lowest eCCE index.

3. The method of claim 2 further comprising, for each ePDCCH detected in a subframe n-k i , calculating the PUCCH resource index n PUCCH,i (1) for transmission in a subframe n as:

n

PUCCH

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i

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1

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=

E

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∑

l

=

0

i

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1

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ePDCCH

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PRB

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lowest

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index

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PRB

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offset

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)

+

n

eCCE

+

N

ePUCCH

(

1

)

where n is an integer, K is the set of downlink subframe indexes in the bundling window of subframe n, M is the number of downlink subframes in the bundling window, k i εK, 0≦i≦M−1, N RB,ePDCCH i indicates the ePDCCH physical resource blocks (PRBs) reserved for use in transmitting the ePDCCH in a downlink subframe, I PRB — ePDCCH lowest — index is the lowest PRB index including at least one eCCE of the ePDCCH detected in the subframe n-k i , N PRB,ePDCCH offset indicates the lowest PRB index for ePDCCH transmission, E is the number of eCCEs in one PRB, n eCCE is the lowest index of the eCCE in the ePDCCH detected in subframe n-k i , 0≦n eCCE <E, which is mapped to a PUCCH resource index n PUCCH,i (1) , and N ePUCCH (1) indicates the PUCCH resources offset for the ePDCCH.

4. The method of claim 3 wherein the PUCCH resources offset N ePUCCH (1) is a UE-specific parameter determined by the eNB.

5. The method of claim 2 further comprising, for each ePDCCH detected in a subframe n-k i , calculating the PUCCH resource index n PUCCH,i (1) for transmission in a subframe n as:

n PUCCH,i (1) =E ·Δ·( I PRB — ePDCCH lowest — index −N PRB,ePDCCH offset )+ n eCCE +E·i+N ePUCCH (1)

where n is an integer, K is the set of downlink subframe indexes in the bundling window of subframe n, M is the number of downlink subframes in the bundling window, k i εK, 0≦i≦M−1, N RB,ePDCCH i indicates the ePDCCH physical resource blocks (PRBs) reserved for use in transmitting the ePDCCH in a downlink subframe, I PRB — ePDCCH lowest — index is the lowest PRB index including at least one eCCE of the ePDCCH detected in the subframe n-k i , N PRB,ePDCCH offset indicates the lowest PRB index for ePDCCH-H transmission, E is the number of eCCEs in one PRB, n eCCE is the lowest index of the eCCE in the ePDCCH detected in subframe n-k i , 0≦n eCC <E, which is mapped to a PUCCH resource index n PUCCH,i (1) , N ePUCCH (1) , indicates the PUCCH resources offset for the ePDCCH, and Δ is a specified integer that depends upon the size of the bundling window.

6. The method of claim 5 wherein the PUCCH resources offset N ePUCCH (1) is a UE-specific parameter determined by the eNB.

7. The method of claim 2 further comprising, for each ePDCCH detected in a subframe n-k i , calculating the PUCCH resource index n PUCCH,i (1) for transmission in a subframe n by selecting a value p from {0,1} that satisfies:

N p ≦n eCCE <N p+1

where N 0 =0, N 1 =2, and N 2 =4

and calculating n PUCCH,i (1) as:

n PUCCH,i (1) =E/2·(I PRB — ePDCCH lowest — index −N PRB,ePDCCH offset )+n eCCE +F 1 +F 1 +δ i +N ePUCCH (1) where n is an integer, K is the set of downlink subframe indexes in the bundling window of subframe n, M is the number of downlink subframes in the bundling window, k i εK, 0≦i≦M−1, N RB,ePDCCH i indicates the ePDCCH physical resource blocks (PRBs) reserved for use in transmitting the ePDCCH in a downlink subframe, I PRB — ePDCCH lowest — index is the lowest PRB index including at least one eCCE of the ePDCCH detected in the subframe n-k i , N PRB,ePDCCH offset indicates the lowest PRB index for ePDCCH transmission, E is the number of eCCEs in one PRB, n eCCE is the lowest index of the eCCE in the ePDCCH detected in subframe n-k i , 0≦n eCCE <E, which is mapped to a PUCCH resource index n PUCCH,i (1) , N ePUCCH (1) indicates the PUCCH resources offset for the ePDCCH, Δ is a specified integer that depends upon the bundling window size, and where:

where:

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.

8. The method of claim 7 wherein the PUCCH resources offset N ePUCCH (1) is a UE-specific parameter determined by the eNB.

9. The method of claim 2 further comprising, for each ePDCCH detected in a subframe n-k i , calculating the PUCCH resource index n PUCCH,i (1) , for transmission in a subframe n by selecting a value p from {0,1} that satisfies:

N p ≦n eCCE <N p+1

where N 0 =0, N 1 =2, and N 2 =4

and calculating n PUCCH,i (1) as:

n PUCCH,i (1) =E·Δ·(I PRB — ePDCCH lowest — index −N PRB,ePDCCH offset )+n eCCE +(M−i−1)·N p +i×N p+1 +N ePUCCH (1) where n is an integer, K is the set of downlink subframe indexes in the bundling window of subframe n, M is the number of downlink subframes in the bundling window, k i εK, 0≦i≦M−1, N RB,ePDCCH i indicates the ePDCCH physical resource blocks (PRBs) reserved for use in transmitting the ePDCCH, in a downlink subframe, I PRB — ePDCCH lowest — index is the lowest PRB index including at least one eCCE of the ePDCCH detected in the subframe n-k i , N PRB,ePDCCH offset indicates the lowest PRB index for ePDCCH transmission, E is the number of eCCEs in one PRB, n eCCE is the lowest index of the eCCE in the ePDCCH detected in subframe n-k i , 0≦n eCCE <E, which is mapped to a PUCCH resource index n PUCCH,i (1) , N ePUCCH (1) indicates the PUCCH resources offset for the ePDCCH, Δ is a specified integer that depends upon the bundling window size.

10. The method of claim 9 wherein the PUCCH resources offset N ePUCCH (1) is a UE-specific parameter determined by the eNB.

11. The method of claim 2 further comprising, for each ePDCCH detected in a subframe n-k i , calculating the PUCCH resource index n PUCCH,i (1) for transmission in a subframe n as:

n PUCCH,i (1) =Δ·( E ·( I PRB — ePDCCH lowest — index −N PRB,ePDCCH offset )+ n eCCE )+ i+N ePUCCH (1)

where n is an integer, K is the set of downlink subframe indexes in the bundling window of subframe n, M is the number of downlink subframes in the bundling window, k i εK, 0≦i≦M−1, N RB,ePDCCH i indicates the ePDCCH physical resource blocks (PRBs) reserved for use in transmitting the ePDCCH in a downlink subframe, I PRB — ePDCCH lowest — index is the lowest PRB index including at least one eCCE of the ePDCCH detected in the subframe n-k i , N PRB,ePDCCH offset indicates the lowest PRB index for ePDCCH transmission, E is the number of eCCEs in one PRB, n eCCE is the lowest index of the eCCE in the ePDCCH detected in subframe n-k i , 0≦n eCCE <E, which is mapped to a PUCCH resource index n PUCCH,i (1) , N ePUCCH (1) indicates the PUCCH resources offset for the ePDCCH, and Δ is a specified integer that depends upon the bundling window size.

12. The method of claim 11 wherein the PUCCH resources offset N ePUCCH (1) is a UE-specific parameter determined by the eNB.

13. The device of claim 1 wherein the processing circuitry is further to detect the ePDCCH in a downlink subframe belonging to a specified bundling window of M indexed downlink subframes and wherein the PUCCH resource is defined by a PUCCH resource index n PUCCH,i (1) that is a function of subframe index, lowest index of a PRB containing at least one eCCE in the detected ePDCCH, and lowest eCCE index.

14. The device of claim 13 wherein the processing circuitry is further to, for each ePDCCH detected in a subframe n-k i , calculate the PUCCH resource index n PUCCH,i (1) for transmission in a subframe n as:

n

PUCCH

,

i

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1

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=

E

·

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∑

l

=

0

i

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1

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+

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PRB

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lowest

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index

-

N

PRB

,

ePDCCH

offset

)

)

+

n

eCCE

+

N

ePUCCH

(

1

)

where n is an integer, K is the set of downlink subframe indexes in the bundling window of subframe n, M is the number of downlink subframes in the bundling window, k i εK, 0≦i ≦M-1, N RB,ePDCCH i indicates the ePDCCH physical resource blocks (PRBs) reserved for use in transmitting the ePDCCH in a downlink subframe, I PRB — ePDCCH lowest — index is the lowest PRB index including at least one eCCE of the ePDCCH detected in the subframe n-k 1 , N PRB,ePDCCH offset indicates the lowest PRB index for ePDCCH transmission, E is the number of eCCEs in one PRB, n eCCE is the lowest index of the eCCE in the ePDCCH detected in subframe n-k i , 0≦n eCCE <E, which is mapped to a PUCCH resource index n PUCCH,i (1) , and N ePUCCH (1) indicates the PUCCH resources offset for the ePDCCH.

15. The device of claim 13 wherein the processing circuitry is further to, for each ePDCCH detected in a subframe n-k i , calculate the PUCCH resource index n PUCCH,i (1) for transmission in a subframe n as:

n PUCCH,i (1) =E ·Δ·( I PRB — ePDCCH lowest — index −N PRB,ePDCCH offset ) +n eCCE +E·i+N ePUCCH (1)

where n is an integer, K is the set of downlink subframe indexes in the bundling window of subframe n, M is the number of downlink subframes in the bundling window, k i εK, 0≦i≦M−1, N RB,ePDCCH i indicates the ePDCCH physical resource blocks (PRBs) reserved for use in transmitting the ePDCCH in a downlink subframe, I PRB — ePDCCH lowest — index is the lowest PRB index including at least one eCCE of the ePDCCH detected in the subframe n-k i , N PRB,ePDCCH offset indicates the lowest PRB index for ePDCCH transmission, E is the number of eCCEs in one PRB, n eCCE is the lowest index of the eCCE in the ePDCCH detected in subframe n-k i , 0≦n eCCE <E, which is mapped to a PUCCH resource index n PUCCH,i (1) , N ePUCCH (1) indicates the PUCCH resources offset for the ePDCCH, and Δ is a specified integer that depends upon the size of the bundling window.

16. The device of claim 13 wherein the processing circuitry is further to, for each ePDCCH detected in a subframe n-k i , calculate the PUCCH resource index n PUCCH,i (1) for transmission in a subframe n by selecting a value p from {0,1} that satisfies:

N p ≦n eCCE <N p+1

where N 0 =0, N 1 =2, and N 2 =4

and calculate n PUCCH,i (1) as:

n PUCCH,i (1) =E/2·(I PRB — ePDCCH lowest — index −N PRB,ePDCCH offset )+n eCCE +F 1 +F 1 +δ i +N ePUCCH (1) where n is an integer, K is the set of downlink subframe indexes in the bundling window of subframe n, M is the number of downlink subframes in the bundling window, k i εK, 0≦i≦M−1, N RB,ePDCCH i indicates the ePDCCH physical resource blocks (PRBs) reserved for use in transmitting the ePDCCH in a downlink subframe, I PRB — ePDCCH lowest — index is the lowest PRB index including at least one eCCE of the ePDCCH detected in the subframe n-k i , N PRB,ePDCCH offset indicates the lowest PRB index for ePDCCH transmission, E is the number of eCCEs in one PRB, n eCCE is the lowest index of the eCCE in the ePDCCH detected in subframe n-k i , 0≦n eCCE <E, which is mapped to a PUCCH resource index n PUCCH,i (1) , N ePUCCH,i (1) indicates the PUCCH resources offset for the ePDCCH, Δ is a specified integer that depends upon the bundling window size, and where:

where:

F

1

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∑

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0

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=

M

-

i

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2

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N

RB

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ePDCCH

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2

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and

δ

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N

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ePDCCH

lowest

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index

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.

17. The device of claim 13 wherein the processing circuitry is further to, for each ePDCCH detected in a subframe n-k i , calculate the PUCCH resource index n PUCCH,i (1) for transmission in a subframe n by selecting a value p from {0,1} that satisfies:

N p ≦n eCCE <N p+1

where N 0 =0, N 1 =2, and N 2 =4

and calculate n PUCCH,i (1) as:

n PUCCH,i (1) =E ·Δ·( I PRB — ePDCCH lowest — index −N PRB,ePDCCH offset ) +n eCCE +( M−i− 1) ·N p +i×N p+1 +N ePUCCH (1)

where n is an integer, K is the set of downlink subframe indexes in the bundling window of subframe n, M is the number of downlink subframes in the bundling window, k i εK, 0≦i≦M−1, N RB,ePDCCH i indicates the ePDCCH physical resource blocks (PRBs) reserved for use in transmitting the ePDCCH in a downlink subframe, I PRB — ePDCCH lowest — index is the lowest PRB index including at least one eCCE of the ePDCCH detected in the subframe n-k i , N PRB,ePDCCH offset indicates the lowest PRB index for ePDCCH transmission, E is the number of eCCEs in one PRB, n eCCE is the lowest index of the eCCE in the ePDCCH detected in subframe n-k i , 0≦n eCCE <E, which is mapped to a PUCCH resource index n PUCCH,i (1) , N ePUCCH (1) indicates the PUCCH resources offset for the ePDCCH, Δ is a specified integer that depends upon the bundling window size.

18. The device of claim 13 wherein the processing circuitry is further to, for each ePDCCH detected in a subframe n-k i , calculate the PUCCH resource index n PUCCH,i (1) for transmission in a subframe n as:

n PUCCH,i (1) =Δ·( E ·( I PRB — ePDCCH lowest — index −N PRB,ePDCCH offset ) +n eCCE ) i+N ePUCCH (1)

where n is an integer, K is the set of downlink subframe indexes in the bundling window of subframe n, M is the number of downlink subframes in the bundling window, k i εK, 0≦i≦ M−1, N RB,ePDCCH i indicates the ePDCCH physical resource blocks (PRBs) reserved for use in transmitting the ePDCCH in a downlink subframe, I PRB ePDCCH lowest — index the lowest PRB index including at least one eCCE of the ePDCCH detected in the subframe n-k i , N PRB,ePDCCH offset indicates the lowest PRB index for ePDCCH transmission, E is the number of eCCEs in one PRB, n eCCE is the lowest index of the eCCE in the ePDCCH detected in subframe n-k i , 0≦n eCCE <E, which is mapped to a PUCCH resource index n PUCCH,i (1) , N ePUCCH (1) indicates the PUCCH resources offset for the ePDCCH, and Δ is a specified integer that depends upon the bundling window size.

19. A method for operating an evolved Node B (eNB) in a in an LTE (Long Term Evolution) network using TDD (time division duplex) mode, comprising:

transmitting data to a UE (user equipment) via a downlink physical downlink shared channel (PDSCH) in a subframe;

allocating PDSCH resources to the UE for the subframe in an enhance physical downlink control channel (ePDCCH) made up of one or more enhanced control channel elements (eCCEs) contained within physical resource blocks (PRBs) that are indexed in a cell-specific manner;

allocating a physical uplink control channel (PUCCH) resource to the UE for acknowledging the transmitted data by implicitly indicating the PUCCH resource in the ePDCCH;

wherein the ePDCCH is transmitted in a downlink subframe belonging to a specified bundling window of M indexed downlink subframes and wherein the PUCCH resource is defined by a PUCCH resource index n PUCCH,i (1) and further comprising, for each subframe in the bundling window having an ePDCCH allocating downlink resources, calculating the PUCCH resource index n PUCCH,i (1) such that consecutive PUCCH resource indices are mapped to by the ePDCCHs ordered in accordance with an ordered list of the eCCEs making up the ePDCCHs where the eCCEs are: 1) ordered first according to subframe index, then according to PRB index, and then according to eCCE index, 2) ordered first according to PRB index, then according to subframe index, and then according to eCCE index, 3) ordered first according to slot number within the subframe, then according to subframe index, then according to PRB index, and then according to eCCE index, 4) ordered first according to PRB index , then according to slot number within the subframe, then according to subframe index, and then according to eCCE index, or 5) ordered first according to PRB index , then according to eCCE index, then according to subframe index.

20. The method of claim 19 wherein the PUCCH resource is defined by a PUCCH resource index n PUCCH,i (1) that is a function of subframe index, lowest index of a PRB containing at least one eCCE of the detected ePDCCH, and lowest eCCE index of the detected ePDCCH.

21. The method of claim 20 wherein the PUCCH resource index n PUCCH,i (1) is further a function of a PUCCH resources offset n ePUCCH (1) that is determined by the eNB in a UE-specific manner.

22. A device operating as user equipment (LIE) in an LIE network, comprising:

an RE transceiver for providing an LIE air interface for communicating with a base station operating as an enhanced/evolved Node B (eNB); and

processing circuitry to:

receive transmitted downlink resource allocations from an eNB in an enhanced physical downlink control channel (ePDCCH) made up of one or more indexed enhanced control channel elements (eCCEs) contained within indexed physical resource blocks (PRBs);

detect an ePDCCH allocating downlink resources in a subframe belonging to a specified bundling window of M indexed subframes and transmit a hybrid-ARQ acknowledgement corresponding to the detected ePDCCH via a physical uplink control channel (PUCCH) resource defined by a PUCCH resource index n PUCCH,i (1) that is a function of subframe index, PRB index, and eCCE index; and,

for each subframe in the bundling window having an ePDCCH allocating downlink resources, calculate the PUCCH resource index n PUCCH,i (1) such that consecutive PUCCH resource indices are mapped to by the ePDCCHs ordered in accordance with an ordered list of the eCCEs making up the ePDCCHs where the eCCEs are: 1) ordered first according to subframe index, then according to PRB index, and then according to eCCE index, 2) ordered first according to PRB index, then according to subframe index, and then according to eCCE index, 3) ordered first according to slot number within the subframe, then according to subframe index, then according to PRB index, and then according to eCCE index, 4) ordered first according to PRB index, then according to slot number within the subframe, then according to subframe index, and then according to eCCE index, or 5) ordered first according to PRB index, then according to eCCE index, then according to subframe index.