| 摘要 |
PURPOSE:To exclude the effect of a frequency error and a phase error by generating a carrier and a frequency conversion signal in a transmitter and a receiver based on a data clock signal so as to eliminate the need of a special carrier reproduction system. CONSTITUTION:A clock signal of a base band signal processing circuit 1 is used for a reference signal and PLLs 4, 5, 6 generate respectively a speed conversion clock signal for a base band signal processing circuit 1, a modulation local signal for a modulator 2, and a local signal for a transmitter 3 to provide them. On the other hand, in the demodulator side, a clock extract section 10 extracts a clock signal synchronously with the signal speed for a radio period from an output of a receiver 7 and PLLs 11, 12, 13 generate a local signal of the receiver 7, a demodulation local signal of a demodulator 8 and a speed conversion clock signal for a base band signal processing circuit 9 respectively based on the clock signal as the reference signal to provide them. thus, the production of a frequency error within a radio section is eliminated and high accuracy is attained and the configuration of the demodulator is simplified. |
