Systems and Methods for supporting carrier aggregation with different TDD configurations are proposed. In a first novel aspect, corresponding apparatus structure is described. In a second novel aspect, aggregation constraint is discussed. In a third novel aspect, transceiving mechanisms over multiple component carriers in DL/UL overlapped subframes are proposed. For simultaneous DL/UL transceiving, band combination indication methods are proposed, and HARQ feedback mechanisms are proposed. For non-simultaneous DL/UL transceiving, transceiving configuration methods are proposed, and the same HARQ feedback mechanisms are proposed. In a fourth novel aspect, CQI/RLM/RRM measurement mechanisms are proposed. In a fifth novel aspect, UE capability signaling mechanisms are proposed. The objective is to support flexible aggregation, to enhance DL data throughout, and to improve UL transmit power efficiency.