Method and apparatus for component carrier aggregation in wireless communications

A method implemented by a wireless transmit/receive unit (WTRU), the method comprising:

• receiving search space restriction information, wherein the search space restriction information comprises an indication of which aggregation levels should be used for decoding physical downlink control channel (PDCCH) candidates in a search space, and the search space restriction information further comprises an indication of which control channel element (CCE) candidates should be used to attempt to decode a PDCCH candidate at a given aggregation level;
• decoding a control channel transmission in accordance with the search space restriction information, the control channel transmission comprising downlink control information for a data transmission;
• and
• processing the data transmission in accordance with the downlink control information comprised in the control channel transmission.

A network node comprising a processor configured to:

• send search space restriction information to a wireless transmit/receive unit (WTRU), wherein the search space restriction information comprises an indication of which aggregation levels should be used by the WTRU for decoding physical downlink control channel (PDCCH) candidates in a search space, and the search space restriction information further indicates which control channel element (CCE) candidates should be used by the WTRU to attempt to decode a PDCCH candidate at a given aggregation level;
• send a control channel transmission in accordance with the search space restriction information, the control channel transmission comprising downlink control information for a data transmission;
• and
• process the data transmission in accordance with the downlink control information comprised in the control channel transmission.