Resource organization in an apparatus and method for carrier aggregation

1. A method of determining, in a network node, communication resources on a downlink channel from the network node to a user equipment in a wireless communication network, the method comprising:

determining a channel sequence based on an offset value, a first physical resource block index of a transmission on a physical uplink shared channel (PUSCH) by the user equipment, and on a cyclic shift of uplink demodulation reference signals (DMRS) transmitted by the user equipment;

determining a channel group without the offset value and based on the first physical resource block index and the cyclic shift; and

determining the communication resources on the downlink channel based on the channel group and the channel sequence;

wherein determining the channel group and the channel sequence comprises determining the channel group and the channel sequence according to:

n PHICH group =( I PRB — RA lowest — index +n DMRS )mod N PHICH group +I PHICH N PHICH group

n PHICH seq =(└ I PRB — RA lowest — index /N PHICH group ┘+n DMRS )+ os PHICH seq,n )mod 2 N SF PHICH

in which n PHICH group represents the channel group, n PHICH seq represents the channel sequence, I PRB — RA lowest — index represents the first physical resource block index, n DMRS represents the cyclic shift, N PHICH group represents a number of available channel groups, I PHICH is either zero or unity, N SF PHICH represents a spreading factor of the downlink channel, and os PHICH seq,n represents the offset value.

2. The method of claim 1 , further comprising determining the offset value, wherein the offset value is in a range from zero to twice a spreading factor of the downlink channel.

3. The method of claim 2 , wherein determining the offset value comprises determining the offset value based on an index of a component carrier where the transmission on the PUSCH takes place.

4. The method of claim 1 , further comprising transmitting the offset value to the user equipment.

5. A method of determining, in a user equipment in a wireless communication network, communication resources on a downlink channel from a network node to the user equipment, the method comprising:

determining a channel sequence based on an offset value, on a first physical resource block index of a transmission on a physical uplink shared channel (PUSCH) by the user equipment, and on a cyclic shift of uplink demodulation reference signals (DMRS) transmitted by the user equipment;

determining a channel group without the offset value and based on the first physical resource block index and the cyclic shift; and

determining the communication resources on the downlink channel based on the channel group and the channel sequence;

wherein determining the channel group and channel sequence comprises determining the channel group and the channel sequence according to:

n PHICH group =( I PRB — RA lowest — index +n DMRS )mod N PHICH group +I PHICH N PHICH group

n PHICH seq =(└ I PRB — RA lowest — index /N PHICH group ┘+n DMRS )+ os PHICH seq,n )mod 2 N SF PHICH

in which n PHICH group represents the channel group, n PHICH seq represents the channel sequence, I PRB — RA lowest index represents the first physical resource block index, n DMRS represents the cyclic shift, N PHICH group represents a number of available channel groups, I PHICH is either zero or unity, N SF PHICH represents a spreading factor size used for channel transmissions, and os PHICH seq,n represents the offset value.

6. The method of claim 5 , wherein the offset value comprises a value in a range from zero to twice a spreading factor of the downlink channel.

7. The method of claim 5 , wherein the offset value is based on an index of a component carrier where the transmission on the PUSCH takes place.

8. The method of claim 5 , further comprising receiving the offset value from the network node.

9. An arrangement in a network node for determining communication resources on a downlink channel from the network node to a user equipment in a wireless communication network, the arrangement comprising an electronic processor circuit configured to:

determine a channel sequence based on an offset value, on a first physical resource block index of a transmission on a physical uplink shared channel (PUSCH) by the user equipment, and on a cyclic shift of uplink demodulation reference signals (DMRS) transmitted by the user equipment;

determine a channel group without the offset value and based on the first physical resource block index and the cyclic shift; and

determine the communication resources on the downlink channel based on the channel group and the channel sequence;

wherein the electronic processing circuit is configured to determine the channel group and channel sequence according to:

n PHICH group =( I PRB — RA lowest — index +n DMRS )mod N PHICH group +I PHICH N PHICH group

n PHICH seq =(└ I PRB — RA lowest — index /N PHICH group ┘+n DMRS )+ os PHICH seq,n )mod 2 N SF PHICH

in which n PHICH group represents the channel group, n PHICH seq represents the channel sequence, I PRB — RA lowest index represents the first physical resource block index, n DMRS represents the cyclic shift, N PHICH group represents a number of available channel groups, I PHICH is either zero or unity, N SF PHICH represents a spreading factor of the downlink channel, and os PHICH seq,n represents the offset value.

10. The arrangement of claim 9 , wherein the network node determines the offset value, and wherein the offset value comprises a value in a range from zero to twice a spreading factor of the downlink channel.

11. The arrangement of claim 9 , wherein the offset value is determined based on an index of a component carrier where the PUSCH transmission takes place.

12. The arrangement of claim 9 , wherein the arrangement further comprises a radio circuit configured to transmit the offset value to the user equipment.

13. An arrangement in a user equipment for determining communication resources on a downlink channel from a network node to the user equipment in a wireless communication network, the arrangement comprising an electronic processor circuit configured to:

determine a channel sequence based on an offset value, on a first physical resource block index of a transmission on a physical uplink shared channel (PUSCH) by the user equipment, and on a cyclic shift of uplink demodulation reference signals (DMRS) transmitted by the user equipment;

determine a channel group without the offset value and based on the first physical resource block index and the cyclic shift; and

determine the communication resources on the downlink channel based on the channel group and the channel sequence;

wherein the electronic processor circuit is configured to determine the channel group and channel sequence according to:

n PHICH group =( I PRB — RA lowest — index +n DMRS )mod N PHICH group +I PHICH N PHICH group

n PHICH seq =(└ I PRB — RA lowest — index /N PHICH group ┘+n DMRS )+ os PHICH seq,n )mod 2 N SF PHICH

in which n PHICH group represents the channel group, n PHICH seq represents the channel sequence, I PRB — RA lowest index represents the first physical resource block index, n DMRS represents the cyclic shift, N PHICH group represents a number of available channel groups, I PHICH is either zero or unity, N SF PHICH represents a spreading factor size used for channel transmissions, and os PHICH seq,n represents the offset value.

14. The arrangement of claim 13 , wherein the offset value comprises a value in a range from zero to twice a spreading factor of the downlink channel.

15. The arrangement of claim 13 , wherein the offset value is based on an index of a component carrier where the transmission on the PUSCH takes place.

16. The arrangement of claim 13 , further comprising a radio configured to receive the offset value from the network node.