Patent ID: 8130630

Claim:
A downlink signal generation apparatus in an orthogonal frequency division multiplexing (OFDM)-based cellular system, the downlink signal generation apparatus comprising: a pilot pattern generator for generating pilot patterns respectively corresponding to a plurality of sub-frames that form one frame of a downlink signal, wherein the pilot pattern generator generates each pilot pattern by computing a product of a cell-specific scrambling code for identifying a cell and a cell group-specific code for identifying a cell-group in which the cell is included; and a time-frequency mapping unit for generating the downlink signal by mapping the pilot pattern to the time-frequency domain, wherein a plurality of cells included in the same cell group have the same cell group-specific code, and the cell-specific scrambling codes are different for the respective cells and the same for the respective sub-frames, and the pilot pattern generator determines a second code according to a cell-group number, the second code corresponding to a product of a first code among the n-th code sequence of the m-th sub-frame and a first code among the n-th code sequence of the (m+1)-th sub-frame among the plurality of sub-frames, the first code among the n-th code sequence of the m-th sub-frame corresponds to a product of the n-th pilot symbol and the (n+1)-th pilot symbol of the m-th sub-frame, and the first code among the n-th code sequence of the (m+1)-th sub-frame corresponds to a product of the n-th pilot symbol and the (n+1)-th pilot symbol of the (m+1)-th sub-frame.