Self- and cross- carrier scheduling

1. A method for transmitting or receiving data in a wireless communication system supporting a plurality of carriers including a component carrier and an additional carrier accessible by a listen before talk approach, the method comprising:

monitoring a search space on a cross-scheduling component carrier for detecting downlink control information (DCI) having a carrier identification field indicating one of the cross-scheduling component carrier and the additional carrier,

wherein the search space is specified by a subset of resources, associated with the carrier identification field indicating the cross-scheduling component carrier but is not associated with the carrier identification filed indicating the additional carrier; and

transmitting or receiving data on the carriers in accordance with the received DCI,

wherein the DCI carrying an uplink grant for the additional carrier is formatted in accordance with DCI Format 0 of 3GPP LTE-A, and the DCI carrying a downlink grant for the cross-scheduling component carrier and/or other carriers is formatted in accordance with DCI Format 2D of 3GPP LTE-A which has a size larger than DCI Format 0,

wherein a size of the DCI carrying the uplink grant for the additional carrier is padded to a size of the DCI carrying the downlink grant for the cross-scheduling component carrier and/or other carriers, and

wherein a configuration based on the DCI detected in the search space on the cross-scheduling component carrier for the additional carrier is only applied for a transmission in case of a grant for uplink but is discarded in case of a grant for downlink.

2. The method according to claim 1 , wherein the monitoring is performed for the DCI for the component carrier and the DCI for the additional carrier having the same determined sizes.

3. The method according to claim 1 , wherein a size of the DCI transmitted on the component carrier for configuring uplink of the component carrier is the same as a size of the DCI transmitted for configuring uplink of the additional carrier.

4. The method according to claim 1 , wherein a size of the DCI transmitted on the component carrier for configuring uplink of the additional carrier is the same as a size of the DCI transmitted on the component carrier for configuring downlink of the additional carrier.

5. The method according to claim 1 , wherein the size of the DCI carrying the uplink grant for the additional carrier is padded to a size of the DCI carrying an uplink grant for the cross-scheduling component carrier and/or other carriers, which has a size larger than the DCI carrying the uplink grant for the additional carrier.

6. The method according to claim 1 , wherein

the DCI carrying the uplink grant for the additional carrier on the cross-scheduling component carrier has the same size as the DCI carrying an uplink grant for the cross-scheduling component carrier on which the DCI is received, and

a size of a resource block allocation field in the DCI carrying an uplink grant for the component carrier on which the DCI is received is larger than a size of a resource block allocation field in the DCI carrying the uplink grant for the additional carrier on the component carrier.

7. The method according to claim 1 , comprising:

monitoring a search space on the additional carrier for detecting DCI having no carrier identification field and relating to downlink on the additional carrier, and

receiving data on the additional carrier in accordance with the DCI detected.

8. The method according to claim 1 , wherein the DCI includes at least one of:

the carrier indication field for identifying one of the carriers for which a grant is designated when the DCI is carried on the cross-scheduling component carrier and relates to uplink, and

an uplink/downlink indicator specifying whether the DCI relates to uplink or downlink if the DCI relating to uplink and downlink have the same sizes.

9. The method according to claim 1 , wherein the DCI carries either uplink or downlink grant or no grant but a configuration relating to uplink or downlink.

10. A method for transmitting or receiving data in a wireless communication system supporting a plurality of carriers including a component carrier and an additional carrier accessible by a listen before talk approach, the method comprising:

transmitting, in a search space on a cross-scheduling component carrier, downlink control information (DCI) having a carrier identification field indicating one of the cross-scheduling component carrier and the additional carrier,

wherein the search space is specified by a subset of resources, associated with the carrier identification field indicating the cross-scheduling component carrier but is not associated with the carrier identification field indicating the additional carrier; and

receiving or transmitting data on the carriers in accordance with the transmitted DCI,

wherein the DCI carrying an uplink grant for the additional carrier is formatted in accordance with DCI Format 0 of 3GPP LTE-A, and the DCI carrying a downlink grant for the cross-scheduling component carrier and/or other carriers is formatted in accordance with DCI Format 2D of 3GPP LTE-A which has a size larger than DCI Format 0,

wherein a size of the DCI carrying the uplink grant for the additional carrier is padded to a size of the DCI carrying the downlink grant for the cross-scheduling component carrier and/or other carriers, and

wherein a configuration based on the DCI detected in the search space on the cross-scheduling component carrier for the additional carrier is only applied for a transmission in case of a grant for uplink but is discarded in case of a grant for downlink.

11. An apparatus for transmitting or receiving data in a wireless communication system supporting a plurality of carriers including a component carrier and an additional carrier accessible by a listen before talk approach, the apparatus comprising:

circuitry, which, in operation, monitors a search space on a cross-scheduling component carrier for detecting downlink control information (DCI) having a carrier identification field indicating one of the cross-scheduling component carrier and the additional carrier,

wherein the search space is specified by a subset of resources, associated with carrier identification field indicating the cross-scheduling component carrier but is not associated with the carrier identification field indicating the additional carrier; and

a transceiver which, in operation, transmits or receives data on the carriers in accordance with the received downlink DCI.

wherein the DCI carrying an uplink grant for the additional carrier is formatted in accordance with DCI Format 0 of 3GPP LTE-A, and the DCI carrying a downlink grant for the cross-scheduling component carrier and/or other carriers is formatted in accordance with DCI Format 2D of 3GPP LTE-A which has a size larger than DCI Format 0,

wherein a size of the DCI carrying the uplink grant for the additional carrier is padded to a size of the DCI carrying the downlink grant for the cross-scheduling component carrier and/or other carriers, and

wherein a configuration based on the DCI detected in the search space on the cross-scheduling component carrier for the additional carrier is only applied for a transmission in case of a grant for uplink but is discarded in case of a grant for downlink.

12. An apparatus for transmitting or receiving data in a wireless communication system supporting a plurality of carriers including a component carrier and an additional carrier accessible by a listen before talk approach, the apparatus comprising:

circuitry, which, in operation, generates, in a search space on a cross-scheduling component carrier, downlink control information (DCI) having a carrier identification field indicating one of the cross-scheduling component carrier and the additional carrier,

wherein the search space is specified by a subset of resources, associated with the carrier identification field indicating the cross-scheduling component carrier but is not associated with the carrier identification field indicating the additional carrier; and

a transceiver, which, in operation, receives or transmits data on the carriers in accordance with the transmitted DCI,

wherein the DCI carrying an uplink grant for the additional carrier is formatted in accordance with DCI Format 0 of 3GPP LTE-A, and the DCI carrying a downlink grant for the cross-scheduling component carrier and/or other carriers is formatted in accordance with DCI Format 2D of 3GPP LTE-A which has a size larger than DCI Format 0,

wherein a size of the DCI carrying the uplink grant for the additional carrier is padded to a size of the DCI carrying the downlink grant for the cross-scheduling component carrier and/or other carriers, and

wherein a configuration based on the DCI detected in the search space on the cross-scheduling component carrier for the additional carrier is only applied for a transmission in case of a grant for uplink but is discarded in case of a grant for downlink.