Technologies for compact and low power consumption personal handy-phone system terminals

This paper proposes a very low power consumption one-chip baseband LSI for personal communication terminals. It is composed of a π/4 DQPSK modem, an ADPCM codec, a TDMA-TDD controller and an LAPDC controller. The novel circuit configuration makes it possible to significantly reduce the power consumption of the baseband circuits of personal communication terminals. In addition, by using a novel coherent demodulator and an ADPCM codec with a click noise suppressor, it achieves 2approx.3dB higher-quality voice transmission in terms of required Eb/No in fading environments.