| 摘要 |
PROBLEM TO BE SOLVED: To reduce a carrier leak and reduce adjacent channel power leakage by providing respective local oscillator signals for every channel and executing modulation in an IF frequency band for every channel. SOLUTION: Each carrier signal is held for every channel in a plurality of radio channels, modulation is executed for every channel, and the common- mode component and the orthogonal component of each channel after modulation are respectively added. The added common-mode component and the orthogonal component signals are modulated respectively by using one of LO(local oscillator) signals again. Then differential signal between the modulated signal and the signal obtained by demodulating the signal fedback from a transmitter is respectively obtained for the common-mode component signal and the orthogonal component signal. The common-mode component and the orthogonal component signals added in the IF band are modulated reversely by the differential signal so that orthogonal modulation is attained with the reverse characteristics of nonlinear distortions in a power amplifier. |
