(A) quadrature modulation transmitter using two frequency synthesizers

Abstract

This paper presents a continuous phase phase-shift keying (CP-PSK) modulation scheme and a novel quadrature modulation transmitter architecture. Thanks to the characteristic of the smooth and continuous phase shift, the proposed CP-PSK modulation scheme can be generated by the indirect modulation transmitter. The proposed quadrature modulation architecture consists of only two frequency synthesizers, thereby reducing the RF and analog components such as RF mixers and analog flters. Simulation results show that the bit error rate (BER) and the spectral e±ciency of the proposed methods are close to those of conventional quadrature modulation schemes. The quadrature modulation transmitter can be implemented fully digitally through the proposed architecture if the all digital frequency synthesizers are used.