A method for transmitting a reference signal by a user equipment (UE) in a wireless communication system. The UE generates an uplink reference signal in a subframe comprising first, second, third, fourth, fifth, sixth and seventh orthogonal frequency division multiplexing (OFDM) symbols in time domain and a plurality of subcarriers in frequency domain. The UE transmits the uplink reference signal to a base station in the third, fourth and fifth OFDM symbols. The transmitted uplink reference signal is hopped in the frequency domain, based on a cell specific hopping parameter.