Patent ID: 8023445

Claim:
A relaying method in a Relay Station (RS) in a communication system having a Base Station (BS), a Mobile Station (MS) for communicating with the BS, and the RS for relaying signals between the BS and the MS, comprising: receiving a first pilot sequence from the BS; and replacing the first pilot sequence with a second pilot sequence and transmitting the second pilot sequence to the MS, wherein a partial cross correlation between the first and second pilot sequences is always ‘0’, and wherein when the BS and the RS use a Single Input Single Output (SISO) scheme, the first and second pilot sequences satisfy the following equation for channel estimation at time t, P i,t Q i,t +P i,t−1 Q i,t−1 =0 where P i,t denotes a pilot symbol transmitted from the BS on an i th subcarrier at time t and Q i,t denotes a pilot symbol transmitted from the RS on the i th subcarrier at time t.