| 摘要 |
PROBLEM TO BE SOLVED: To use an amplifier with a small back-off by decreasing the ratio of peak power to mean power of communication data in the multiplexed spread spectrum communication system. SOLUTION: A transmitter 2 in the spread spectrum communication system generates first coded data ϕ3, by multiplying orthogonal processing spread codes with parallel data ϕ5 and sums the products at a base band. Then a sum conversion circuit 13 converts the first coded data ϕ3 into second coded data ϕ4 where a difference between a mean value and a peak is reduced, and the data are amplified at an amplifier 27. A ratio of the peak power to the mean power of the output after the modulation is reduced by such a conversion above. Thus, in the multiplexed spread spectrum communication system, in spite of the use of an amplifier with small back-off, the distortion in communication data and increase in adjacent channel leakage power are prevented. |
