Apparatus and method for performing amp;pgr;/4-DQPSK baseband modulation based on a signal mapping to be simplified

摘要

The present invention is an apparatus and method for performing a &pgr;/4-DQPSK baseband modulation based on a signal mapping to be simplified. The apparatus mainly comprises a memory unit and as processing unit. The memory unit stores a plurality of parameters and their corresponding tabular data of a low pass filter, and the parameters and their corresponding tabular data are simplified in advance. The low pass filter is used for reducing the bandwidth of the apparatus and increasing the utilization of the bandwidth. The processing, unit bases on the input digital data and the tabular data in the memory unit to generate a digital in-phase signal I_n and a digital quadrature-phase signal Q_n.