Antennas, Base and Mobile Stations -9.Digital Mova
Unlike the analog system, the digital system adopts /4 shift QPSK for the modulation system and TDMA as the access system. Accordingly, the development of digital Mova required a new configuration for modulators and demodulators and required higher frequency speeds and improved efficiency.
The basic configuration of the digital Mova employs an RF-band quadrature modulator and a high-efficiency power amplifier in order to generate advanced and high-efficiency /4 shift QPSK modulation waves for transmission. Power consumption during reception is minimized by adopting an ACT demodulator, and an antenna switchover diversity system utilizing TDMA characteristics is introduced to make the reception component as compact as possible. Moreover, by adopting a DLPS synthesizer for the high-speed channel switchover synthesizer circuit, frequency switchover time is reduced by 90% or more.
Basic Configuration of Digital Mova