Subframe component reduction and notification in a heterogeneous wireless communication system

1. A method, in a wireless base unit that supports carrier aggregation with at least an anchor carrier and an additional component carrier, comprising:

determining a truncation time period in order to create a truncated subframe component on the additional component carrier;

transmitting the truncated subframe component on the additional component carrier; and

transmitting truncation time period information within a control region of a subframe on the anchor carrier.

2. A method according to claim 1 wherein the transmitting truncation time period information comprises:

using at least a portion of the resources reserved for Physical Hybrid-ARQ Indicator Channel (PHICH) signaling.

3. A method according to claim 2 wherein the using comprises:

using Radio Resource Control (RRC) signaling to reserve default PHICH resources and additional PHICH resources; and

using the additional PHICH resources for truncation time period information signaling.

4. A method according to claim 1 wherein the transmitting truncation time period information comprises:

using Control Channel Element (CCE) resources.

5. A method according to claim 1 further comprising:

receiving information regarding at least a duration of a control region in a subframe to be transmitted by an uncoordinated base unit on the additional component carrier.

6. A method according to claim 5 wherein the truncated subframe component does not interfere with the control region in the subframe transmitted by the uncoordinated base unit.

7. A method according to claim 1 further comprising:

transmitting a control message on the anchor carrier, for indicating downlink control information regarding assigned resources on the additional component carrier.

8. A method according to claim 1 wherein the truncated subframe component carries at least one Physical Downlink Shared Channel (PDSCH).

9. A method according to claim 1 wherein the truncated subframe component is a front-truncated subframe component.

10. A method, in a wireless communication remote terminal that supports carrier aggregation with at least an anchor carrier and an additional component carrier, comprising:

searching a control region of a subframe received on the anchor carrier for truncation information for a subframe component received on the additional component carrier;

using the truncation information to determine a boundary of a data region in the subframe component received on the additional component carrier; and

receiving data in the subframe component received on the additional component carrier based on the boundary of the data region.

11. A method according to claim 10 further comprising:

receiving a notification that the control region of the subframe received on the anchor carrier carries the truncation information for the subframe component received on the additional component carrier.

12. A method according to claim 11 wherein the receiving the notification comprises:

implicitly receiving the notification based on one or more of (1) a downlink bandwidth of the anchor carrier, (2) a Physical Cell Identifier (PCID) of the anchor carrier, (3) a subframe index of the subframe transmitted on the anchor carrier.

13. A method according to claim 11 wherein the notification indicates that the truncation information is carried in resources reserved for Physical Hybrid-ARQ Indicator Channel (PHICH) signaling.

14. A method according to claim 11 wherein the notification indicates that the truncation information is carried in Control Channel Element (CCE) resources.

15. A method according to claim 11 wherein the receiving the notification comprises:

receiving either a Radio Resource Control (RRC) signal or a broadcast signal.

16. A method according to claim 10 wherein the searching comprises:

decoding CCE resources to obtain the truncation information.

17. A method according to claim 10 wherein the searching comprises:

decoding PHICH resources to obtain the truncation information.

18. A method according to claim 10 wherein the searching comprises:

receiving a control message on the anchor carrier and using the control message to determine downlink control information regarding assigned resources on the additional component carrier.

19. A method according to claim 10 wherein the receiving data comprises:

receiving data carried on a Physical Downlink Shared Channel (PDSCH) in the subframe component received on the additional component carrier.

20. A wireless communication remote terminal that supports carrier aggregation with at least an anchor carrier and an additional component carrier, comprising:

a wireless transceiver;

a controller, coupled to the wireless transceiver, for

configuring the wireless transceiver to receive a subframe on the anchor carrier and the additional component carrier;

searching a control region of the subframe on the anchor carrier for truncation information for a subframe component received on the additional component carrier;

using the truncation information to determine a boundary of a data region in the subframe component received on the additional component carrier; and

receiving data in the subframe component received on the additional component carrier based on the boundary of the data region.