Digital radio transmission-reception apparatus

摘要

A transmission-reception apparatus in a digital radio communication system for minimizing electrical interference within the apparatus by eliminating interference attributable to the use of different frequency generators. The transmission apparatus includes an antenna, a quadrature modulator for quadrature modulating first and second data to be input, an up-converter for increasing a frequency of the quadrature modulated signal to a transmission frequency band and then for supplying the resulting signal to the antenna, a reference frequency generator, a carrier frequency generator for generating a carrier frequency for modulation by being phase-locked with the reference frequency generator, and a frequency multiplier for generating a respective local oscillation frequency for up-conversion by multiplying the carrier frequency by a predetermined positive number. Up-conversion of the quadrature-modulated signal can be performed in a single stage or in a plurality of stages.