Patent ID: 8873519

Claim:
A user equipment configured with at least two serving cells comprising a primary cell (PCell) and a secondary cell (SCell), the PCell and the SCell having different Time Division Duplex (TDD) Uplink-Downlink (UL-DL) configurations, the user equipment comprising: a transmitter configured to transmit first acknowledgement/negative acknowledgement (A/N) in an uplink subframe determined by a reference TDD configuration for the SCell, the first A/N corresponding to a physical downlink shared channel (PDSCH) transmission on the SCell, wherein the reference TDD configuration for the SCell has a greatest number of uplink subframes from among one or more reference TDD configurations for the TDD UL-DL configurations of the PCell and the SCell in Table 1 below: TABLE 1 Reference TDD con- PCell TDD UL-DL configuration figuration 0 1 2 3 4 5 6 SCell TDD 0 0 1, 2, 2, 5 3, 4, 5 4, 5 5 1, 2, 3, UL-DL 4, 5 4, 5, 6 config- 1 1, 2, 4, 1 2, 5 4, 5 4, 5 5 1, 2, 4, uration 5 5 2 2, 5 2, 5 2 5 5 5 2, 5 3 3, 4, 5 4, 5 5 3 4, 5 5 3, 4, 5 4 4, 5 4, 5 5 4, 5 4 5 4, 5 5 5 5 5 5 5 5 5 6 1, 2, 3, 1, 2, 2, 5 3, 4, 5 4, 5 5 6 4, 5, 6 4, 5 where each reference TDD configuration in Table 1 indicates downlink association set indexes (K: {k 0 , k 1 , . . . k M-1 }) for a subframe ‘n’ as defined in Table 2 below: TABLE 2 UL-DL Config- Subframe ‘n’ uration 0 1 2 3 4 5 6 7 8 9 0 — — 6 — 4 — — 6 — 4 1 — — 7, 6 4 — — — 7, 6 4 — 2 — — 8, 7, — — — — 8, 7, — — 4, 6 4, 6 3 — — 7, 6, 11 6, 5 5, 4 — — — — — 4 — — 12, 8, 6, 5, — — — — — — 7, 11 4, 7 5 — — 13, 12, — — — — — — — 9, 8, 7, 54, 11, 6 6 — — 7 7 5 — — 7 7 — where A/N corresponding to PDSCH transmitted in a subframe (n−k i ) (0≦i≦M−1) is transmitted in the subframe ‘n’.