Method and apparatus for channel estimation for radio link between a base station and a relay station

A downlink reception entity for performing downlink reception, the downlink reception entity comprising:

• a reception module configured to receive a downlink signal from a downlink transmission entity;
• a transmission module configured to transmit an uplink signal to the downlink transmission entity;
• and
• a processor configured to control the reception module and the transmission module,
• wherein the processor is further configured to:
• receive, through the reception module, downlink control information by demodulating a Physical Downlink Control Channel (PDCCH) in a first resource block (RB) pair within an RB bundle by using a first Demodulation Reference Signal (DMRS);
• and
• receive, through the reception module, downlink data by demodulating a Physical Downlink Shared Channel (PDSCH) in one or more second RB pairs scheduled by the downlink control information within the RB bundle by using a second DMRS based on an assumption that a same precoder is applied to the scheduled one or more second RB pairs.