Method and apparatus for transmitting HARQ-ACK information in a TDD system supporting carrier aggregation

A communication device configured to transmit uplink control information in a wireless communication system supporting carrier aggregation and operating in time division duplexing (TDD), the communication device comprising:

• a radio frequency (RF) unit;
• and
• a processor operatively connected to the RF unit and configured to:
• when a specific parameter is less than a specific value, generate hybrid automatic repeat request-acknowledgement (HARQ-ACK) bits including an individual bit value corresponding to a respective HARQ-ACK for each of a plurality of component carriers (CCs),
• when the specific parameter is equal to or larger than the specific value, generate the HARQ-ACK bits including bit values corresponding to all HARQ-ACKs for each of the plurality of CCs, and
• control the RF unit to transmit the uplink control information including the generated HARQ-ACK bits,
• wherein when the specific parameter is 5, the specific value is 5 and a number of the bit values is 2, a mapping relationship between the HARQ-ACKs and the bit values is given by the following table:
• HARQ-ACK (0), (1), (2), (3), (4)
• Bit values
• (A, A, A, N/D, any)
• a0, a1
• (A, A, A, A, A) or (A, A, D, D, D)
• b0, b1
• (A, A, A, A, N/D) or (A, D, D, D, D)
• c0, c1
• (N/D, any, any, any, any),
• d0, d1
• or (A, N/D, any, any, any) except for (A, D, D, D, D),
• or (A, A, N/D, any, any) except for (A, A, D, D, D)
• wherein {(a0, a1), (b0, b1), (c0, c1), (d0, d1)} corresponds to one of {(1, 1), (1, 0), (0, 1), (0, 0)}, {(1, 1), (0, 1), (1, 0), (0, 0)}, {(0, 0), (1, 0), (0, 1), (1, 1)} or {(0, 0), (0, 1), (1, 0), (1, 1)}, and
• wherein “A” represents ACK (acknowledgement), “D” represents DTX (discontinuous transmission), “N/D” represents NACK (negative ACK) or DTX, and “any” represents one of ACK, NACK, or DTX.