Arrangement and method for identifying PUCCH format 3 resources
The disclosure relates to a user equipment for a wireless communications system, and to a related method for identifying a resource to use for a transmission of control information on a physical uplink control channel, PUCCH, format 3. The method comprises receiving ( 610 ) a resource index from a serving radio base station, and identifying ( 620 ) the resource to use for the transmission of the control information in a subframe based on the received resource index, wherein the identified resource is within a same confined set of physical resource blocks regardless of if a normal or a shortened PUCCH format 3 is used in the subframe.
1. A method in a user equipment of a wireless communication system, for identifying a resource to use for a transmission of control information on a physical uplink control channel, PUCCH, format 3, the method comprising:
receiving a resource index from a serving radio base station,
identifying the resource to use for the transmission of the control information in a subframe based on the received resource index, wherein the identified resource is within a same confined set of physical resource blocks regardless of if a normal or a shortened PUCCH format 3 is used in the subframe, and
wherein identifying the resource comprises identifying an orthogonal sequence based on an orthogonal sequence index n oc given by the following equation:
n oc =n PUCCH modN SF,1 PUCCH
where n PUCCH is the received resource index, and N SF,1 PUCCH is a number of orthogonal sequences available for a physical resource block in a second time slot of the subframe.
2. The method according to claim 1 , wherein identifying the resource comprises identifying a physical resource block based on the received resource index, wherein the identified physical resource block is the same regardless of if a normal or a shortened PUCCH format 3 is used in the subframe.
3. The method according to claim 2 , wherein the physical resource block is identified based on n PRB given by the following equation:
n
PRB
=
⌊
n
PUCCH
N
SF
,
0
PUCCH
⌋
where n PUCCH is the received resource index and N SF,0 PUCCH is a number of orthogonal sequences available for a physical resource block in a first time slot of the subframe.
4. The method according to claim 1 , wherein identifying the resource comprises:
calculating a modified resource index based on the received resource index and a total number of physical resource blocks available for PUCCH format 3, and
identifying the resource based on the modified resource index, wherein the identified resource is within a same confined set of physical resource blocks regardless of if a normal or a shortened PUCCH format 3 is used in the subframe.
5. The method according to claim 4 , wherein the modified resource index is calculated as a modulo operation with the received resource index as the dividend and the total number of physical resource blocks available for PUCCH format 3 as the divisor.
6. The method according to claim 4 , wherein identifying the resource based on the modified resource index comprises identifying a physical resource block based on n PRB given by the following equation:
n
PRB
=
⌊
n
~
PUCCH
N
SF
,
1
PUCCH
⌋
+
N
start
where ñ PUCCH is the modified resource index, N SF,1 PUCCH is a number of orthogonal sequences available for a physical resource block in a second time slot of the subframe, and N start is a starting position of the confined set of physical resource blocks.
7. The method according to claim 4 , wherein identifying the resource based on the modified resource index comprises identifying an orthogonal sequence based on an orthogonal sequence index n oc given by the following equation:
n oc =ñ PUCCH mod N SF,1 PUCCH
where ñ PUCCH is the modified resource index, and N SF,1 PUCCH is a number of orthogonal sequences available for a physical resource block in a second time slot of the subframe.
8. A user equipment for a wireless communication system, configured to identify a resource to use for a transmission of control information on a physical uplink control channel, PUCCH, format 3, the user equipment comprising:
a receiving unit adapted to receive a resource index from a serving radio base station,
an identifying unit adapted to identify the resource to use for the transmission of the control information in a subframe based on the received resource index, wherein the identified resource is within a same confined set of physical resource blocks regardless of if a normal or a shortened PUCCH format 3 is used in the subframe, and
wherein the identifying unit is adapted to identify an orthogonal sequence based on an orthogonal sequence index n oc given by the following equation:
n oc =n puccH modN SF,1 PUCCH
where n PUCCH is the received resource index, and N SF,1 PUCCH is a number of orthogonal sequences available for a physical resource block in a second time slot of the subframe.
9. The user equipment according to claim 8 , wherein the identifying unit is adapted to identify a physical resource block based on the received resource index, wherein the identified physical resource block is the same regardless of if a normal or a shortened PUCCH format 3 is used in the subframe.
10. The user equipment according to claim 9 , wherein the identifying unit is adapted to identify the physical resource block based on n PRB given by the following equation:
n
PRB
=
⌊
n
PUCCH
N
SF
,
0
PUCCH
⌋
where n PUCCH is the received resource index and N SF,0 PUCCH is a number of orthogonal sequences available for a physical resource block in a first time slot of the subframe.
11. The user equipment according to claim 8 , wherein the identifying unit is further adapted to calculate a modified resource index based on the received resource index and a total number of physical resource blocks available for PUCCH format 3, and to identify the resource based on the modified resource index, wherein the identified resource is within a same confined set of physical resource blocks regardless of if a normal or a shortened PUCCH format 3 is used in the subframe.
12. The user equipment according to claim 11 , wherein the identifying unit is further adapted to calculate the modified resource index as a modulo operation with the received resource index as the dividend and the total number of physical resource blocks available for PUCCH format 3 as the divisor.
13. The user equipment according to claim 11 , wherein the identifying unit is adapted to identify a physical resource block based on n PRB given by the following equation:
n
PRB
=
⌊
n
~
PUCCH
N
SF
,
1
PUCCH
⌋
+
N
start
where ñ PUCCH , is the modified resource index, N SF,1 PUCCH is a number of orthogonal sequences available for a physical resource block in a second time slot of the subframe, and N start is a starting position of the confined set of physical resource blocks.
14. The user equipment according to claim 11 , wherein the identifying unit is adapted to identify an orthogonal sequence based on an orthogonal sequence index n oc given by the following equation:
n oc =ñ PUCCH mod N SF,1 PUCCH
where ñ PUCCH is the modified resource index, and N SF,1 PUCCH is a number of orthogonal sequences available for a physical resource block in a second time slot of the subframe.