The present invention, orthogonal cover code generator, the demodulated reference signal generator, and to those methods. Demodulation reference signal generator is uncorrelated sequence generator for generating a non-correlation sequence for the pilot of the first resource block, using the first orthogonal cover code (OCC) group, of the first resource block first spread-spectrum unit to spread the spectrum of the non-correlation sequence of elements for the pilots to be mapped to the first frequency resource, using a second OCC group, the second of the first resource block a second spread-spectrum unit to spread the spectrum of the elements of the non-correlation sequence for pilot to be mapped to a frequency resource, the first and second frequency resources for a group of the first data stream a adjacent frequency resources, the first and second OCC group are columns mirror each other, the second spread-spectrum unit, the spread spectrum elements to each said first and second frequency resources mapping to mapping unit with a,. Method and apparatus according to the present invention improves the randomization of the pilot, to eliminate the problem of imbalance of the transmission power of the pilot, to satisfy the orthogonality requirement in the region of both time and frequency.