/spl pi//4-shift QPSK digital modulator LSIC for personal communication terminals

摘要

A /spl pi//4-shift QPSK digital modulator LSIC consisting of a digital pulse shaping filter and a baseband quadrature modulator is newly developed. By employing a novel digital filter configuration, the required filter memory is reduced to just 1/2048th that of the conventional modulator. Moreover, since the proposed baseband modulation scheme does not employ a complex multiplier or a quadrature modulator with multipliers, a compact and low power consumption modulator is realized.