A disclosed base station randomizes downlink physical channels in OFDM radio access by scrambling codes suitable for the respective physical channels. The base station includes a base-station-specific scrambling code generating unit configured to generate a base-station-specific scrambling code for randomizing downlink physical channels; a sector-specific orthogonal sequence generating unit configured to generate a sector-specific orthogonal sequence; and a multiplication control unit configured to determine, for each of the physical channels, whether to multiply the base-station-specific scrambling code by the sector-specific orthogonal sequence based on whether each of the physical channels requires soft combining.