Method, UE and basestation for reporting/receiving HARQ ACK/NACK for PDSCH in dynamic TDD configurations

1. A method used in a User Equipment, UE, for reporting Hybrid Automatic Repeat Request, HARQ, acknowledgement, ACK, /non-acknowledgement, NACK, for Physical Downlink Shared Channels, PDSCHs, in dynamic time division duplex, TDD, configurations, the method comprising:

receiving a plurality of PDSCHs in DownLink, DL, subframes associated with an UpLink, UL, subframe and indicated by a DL reference TDD configuration;

dividing the DL subframes into a first subset of DL subframes and a second subset of DL subframes, wherein the first subset of DL subframes is also indicated by an UL reference TDD configuration;

assigning a first set of Physical Uplink Control Channel, PUCCH, resource indices based on resources used in transmission of Physical Downlink Control Channels, PDCCHs, corresponding to the PDSCHs received in the DL subframes of the first subset of DL subframes;

assigning a second set of PUCCH resource indices based on resources used in transmission of PDCCHs corresponding to the PDSCHs received in the DL subframes of the second subset of DL subframes; and

for each of the received PDSCHs, reporting HARQ ACK/NACK using PUCCH resources in an order of the assigned first set of PUCCH resource indices for PDSCHs received in the DL subframes of the first subset of DL subframes and in an order of the assigned second set of PUCCH resource indices for PDSCHs received in the DL subframes of the second subset of DL subframes, characterized in that assigning the first set of PUCCH resource indices and the second set of PUCCH resource indices are based on the following formula:

n PUCCH,i (1) =( M q −i− 1)· N c +i·N c+1 +n CCE,i +N PUCCH (q) ,

wherein n PUCCH,i (1) is a PUCCH resource index determined based on resources used in transmission of PDCCHs corresponding to the PDSCHs received in the DL subframe that is the i th element of the q th subset, M q is the total number of DL subframes in the q th subset, 0≤i<M q , c is selected from {0,1,2,3}, such that N c ≤n CCE,i <N C+1 , N c =max{0,└[N RB DL ·(N sc RB ·c−4)]/36┘} where N RB DL is the number of physical resource blocks, PRBs, in each downlink subframe and where N sc RB is the number of subcarriers in each physical resource block, n CCE,i is the sequence number of the first Control Channel Element, CCE, used for transmission of the corresponding PDCCH in subframe n−k i (q) , k i (q) (q=0,1) is the i th element of the q th subset, a indicates the UL subframe associated with the DL subframes where the plurality of PDSCHs are received, N PUCCH (q) (q==0,1) is an offset for q th subset, wherein q=0 corresponds to one of the first and second subsets of DL subframes and q=1 corresponds to the other one of the first and second subsets of DL subframes.

2. The method according to claim 1 , wherein the second subset of DL subframes comprises all the DL subframes indicated by the DL reference TDD configuration other than DL subframes of the first subset of DL subframes.

3. The method according to claim 1 , wherein the first subset of DL subframes comprises one or more virtual subframes that are added by the UE, wherein the one or more virtual subframes are used for assigning PUCCH resource indices, but not for real PDSCH transmissions.

4. A User Equipment, UE, for reporting Hybrid Automatic Repeat Request, HARQ, acknowledgement, ACK, /non-acknowledgement, NACK, for Physical Downlink Shared Channels, PDSCHs, in dynamic, time division duplex, TDD, configurations, the UE comprising a receiver, a transmitter, a memory and a processor,

wherein

the memory is configured to store TDD configurations;

the processor is configured to control the receiver to receive a plurality of PDSCHs in Downlink, DL, subframes associated with an UpLink, UL, subframe and indicated by a DL reference TDD configuration;

the processor (is configured to divide the DL subframes into a first subset of DL subframes and a second subset of DL subframes, wherein the first subset of DL subframes is also indicated by an UL reference TDD configuration;

the processor is configured to assign a first set of Physical Uplink Control Channel, PUCCH, resource indices based on resources used in transmission of Physical Downlink Control Channels, PDCCHs, corresponding to the PDSCHs received in the DL subframes of the first subset of DL subframes;

the processor is configured to assign a second set of PUCCH resource indices based on resources used in transmission of PDCCHs corresponding to the PDSCHs received in the DL subframes of the second subset of DL subframes; and

the processor is configured to control the transmitter to, for each of the received PDSCHs, report HARQ ACK/NACK using PUCCH resources in an order of the assigned first set of PUCCH resource indices for PDSCHs received in the DL subframes of the first subset of DL subframes and in an order of the assigned second set of PUCCH resource indices for PDSCHs received in the DL subframes of the second subset of DL subframes, characterized in that the processor is configured to assign the first set of PUCCH resource indices and the second set of PUCCH resource indices based on the following formula:

n PUCCH,i (1) =( M q −i− 1)· N c +i·N c+1 +n CCE,i +N PUCCH (q) ,

wherein n PUCCH,j (1) is a PUCCH resource index determined based on resources used in transmission of PDCCHs corresponding to the PDSCHs received in the DL subframe that is the i th element of the q th subset, M q is the total number of DL subframes in the q th subset, 0≤i<M q , cis selected from {0,1,2,3} such that N c ≤n CCE,i <N c+1 , N c =max{0,└[N RB DL ·(N sc RB ·c−4)]/36┘} where N RB DL is the number of physical resource blocks, PRBs, in each downlink subframe and where N sc RB is the number of subcarriers in each physical resource block, n CCE,i is the sequence number of the first Control Channel Element, CCE, used for transmission of the corresponding PDCCH in subframe n−k i (q) , k i (q) (q=0,1) is the i th element of the q th subset, n indicates the UL subframe associated with the DL subframes where the plurality of PDSCHs are received, N PUCCH (q) (q=0,1) is an offset for q th subset, wherein q=0 corresponds to one of the first and second subsets of DL subframes and q=1 corresponds to the other one of the first and second subsets of DL subframes.

5. The UE according to claim 4 , wherein the second subset of DL subframes comprises all the DL subframes indicated by the DL reference TDD configuration other than DL subframes of the first subset of DL subframes.

6. The UE according to claim 4 , wherein the processor is further configured to add one or more virtual subframes to the first subset of DL subframes, wherein the one or more virtual subframes are used for assigning PUCCH resource indices, but not for real PDSCH transmissions.

7. A method used in a Base Station, BS, for receiving Hybrid Automatic Repeat Request, HARQ, acknowledgement, ACK, /non-acknowledgement, HACK, for Physical Downlink Shared Channels, PDSCHs, in dynamic time division duplex, TDD, configurations, the method comprising:

transmitting a plurality of PDSCHs in DownLink, DL, subframes associated with an UpLink, UL, subframe and indicated by a DL reference TDD configuration;

dividing the DL subframes into a first subset of DL subframes and a second subset of DL subframes, wherein the first subset of DL subframes is also indicated by an UL reference TDD configuration;

assigning a first set of Physical Uplink Control Channel, PUCCH, resource indices based on resources used in transmission of Physical Downlink Control Channels, PDCCHs, corresponding to the PDSCHs transmitted in the DL subframes of the first subset of DL subframes;

assigning a second set of PUCCH resource indices based on resources used in transmission of PDCCHs corresponding to the PDSCHs transmitted in the DL subframes of the second subset of DL subframes; and

for each of the transmitted PDSCHs, receiving HARQ ACK/NACK on PUCCH resources in an order of the assigned first set of PUCCH resource indices for PDSCHs transmitted in the DL subframes of the first subset of DL subframes and in an order of the assigned second set of PUCCH resource indices for PDSCHs transmitted in the DL subframes of the second subset of DL subframes, characterized in that assigning the first set of PUCCH resource indices and the second set of PUCCH resource indices are based on the following formula:

n PUCCH,i (1) =( M q −i− 1)· N c +i·N c+1 +n CCE,i +N PUCCH (q) ,

wherein n PUCCH,i (1) is a PUCCH resource index determined based on resources used in transmission of PDCCHs corresponding to the PDSCHs received in the DL subframe that is the i th element of the q th subset, M q is the total number of DL subframes in the q th subset, 0≤i<M q , c is selected from {0,1,2,3} such that N c ≤n CCE,i <N c+1 , N c =max{0,└[N RB DL ·(N sc RB ·c−4)]/36┘} where N RB DL is the number of physical resource blocks, PRBs, in each downlink subframe and where N sc RB is the number of subcarriers in each physical resource block, n CCE,i is the sequence number of the first Control Channel Element, CCE, used for transmission of the corresponding PDCCH In subframe n−k i (q) , k i (q) (q=0,1) is the i th element of the q th subset, n indicates the UL subframe associated with the DL subframes where the plurality of PDSCHs are received, N PUCCH (q) (q=0,1) is an offset for q th subset, wherein q=0 corresponds to one of the first and second subsets of DL subframes and q=1 corresponds to the other one of the first and second subsets of DL subframes.

8. The method according to claim 7 , wherein the second subset of DL subframes comprises all the DL subframes indicated by the DL reference TDD configuration other than DL subframes of the first subset of DL subframes.

9. The method according to claim 7 , wherein the first subset of DL subframes comprises one or more virtual subframes that are added by the BS, wherein the one or more virtual subframes are used for assigning PUCCH resource indices, but not for real PDSCH transmissions.

10. A Base Station, BS, for receiving Hybrid Automatic Repeat Request, HARQ, acknowledgement, ACK, /non-acknowledgement, NACK, for Physical Downlink Shared Channels, PDSCHs, in dynamic time division duplex, TDD, configurations, the BS comprising a receiver, a transmitter, a memory and a processor,

wherein

the memory is configured to store TDD configurations;

the processor is configured to control the transmitter to transmit a plurality of PDSCHs in DownLink, DL, subframes associated with an UpLink, UL, subframe and indicated by a DL reference TDD configuration;

the processor is configured to divide the DL, subframes into a first subset of DL subframes and a second subset of DL subframes, wherein the first subset of DL subframes is also indicated by an UL reference TDD configuration;

the processor is configured to assign a first set of Physical Uplink Control Channel, PUCCH, resource indices based on resources used in transmission of Physical Downlink Control Channels, PDCCHs, corresponding to the PDSCHs transmitted in the DL subframes of the first subset of DL subframes;

the processor is configured to assign a second set of PUCCH resource indices based on resources used in transmission of PDCCHs corresponding to the PDSCHs transmitted in the DL subframes of the second subset of DL subframes; and

the processor is configured to control the receiver to, for each of the transmitted PDSCHs, receive HARQ ACK/NACK on PUCCH resources in an order of the assigned first set of PUCCH resource indices for PDSCHs transmitted in the DL subframes of the first subset of DL, subframes and in an order of the assigned second set of PUCCH resource indices for PDSCHs transmitted in the DL subframes of the second subset of DL subframes, characterized in that the processor is configured to assign the first set of PUCCH resource indices and the second set of PUCCH resource indices based on the following formula:

n PUCCH,i (1) =( M q −i− 1)· N c +i·N c+1 +n CCE,i +N PUCCH (q) ,

wherein n PUCCH,i (1) is a PUCCH resource index determined based on resources used in transmission of PDCCHs corresponding the PDSCHs received in the DL subframe that is the i th element of the q th subset, M q is the total number of DL subframes in the q th subset, 0≤i<M q , is selected from {0,1,2,3} such that N c ≤n CCE,i <N c+1 , N c =max{0,└[N RB DL ·(N sc RB ·c−4)]/36┘} where N RB DL is the number of physical resource blocks, PRBs, in each downlink subframe and where N sc RB is the number of subcarriers in each physical resource block, n CCE,i is the sequence number of the first Control Channel Element, CCE, used for transmission of the corresponding PDCCH ire subframe n−k i (q) , k i (q) (q=0,1) is the i th element of the q th subset, n indicates the UL subframe associated with the DL subframes where the plurality of PDSCHs are received, N PUCCH (q) (q=0,1) is an offset for q th subset, wherein q=0 corresponds to one of the first and second subsets of DL subframes and q=1 corresponds to the other one of the first and second subsets of DL subframes.

11. The BS according to claim 10 , wherein the second subset of DL subframes comprises all the DL subframes indicated by the DL reference TDD configuration other than DL subframes of the first subset of DL subframes.

12. The BS according to claim 10 , wherein the processor (is further configured to add one or more virtual subframes to the first subset of DL subframes, wherein the one or more virtual subframes are used for assigning PUCCH resource indices, but not for real PDSCH transmissions.