Patent ID: 8902876

Claim:
A method of transmitting a downlink subframe in a wireless communication system, the method performed by a base station (BS) and comprising: transmitting a simultaneous transmission indicator to a user equipment (UE) that indicates whether a sounding reference signal (SRS) and a hybrid automatic retransmission request (HARQ) acknowledgement/non-acknowledgement (ACK/NACK) are to be transmitted by the UE in a same subframe; transmitting SRS operation information to the UE that indicates a periodicity of transmission of the SRS and a subframe offset to be used for the transmission of the SRS; receiving the SRS, the HARQ ACK/NACK and a demodulation reference signal (DM-RS) from the UE when the simultaneous transmission indicator indicates that the SRS and the HARQ ACK/NACK are to be transmitted in the same subframe, the DM-RS used by the BS to demodulate the HARQ ACKNACK in an SRS subframe; and receiving the HARQ ACK/NACK and the DM-RS from the UE in the SRS subframe without the SRS when the simultaneous transmission indicator indicates that the SRS and the HARQ ACK/NACK are not to be transmitted in the same subframe, wherein the SRS is received in a last single carrier-frequency division multiple access (SC-FDMA) symbol of the SRS subframe, and wherein the HARQ ACK/NACK and the DM-RS are received in remaining SC-FDMA symbols of the SRS subframe.