PHS (Personal Handyphone System) A digital cordless telephony system developed in Japan and used in China, Taiwan, and throughout Asia. PHS carves out 75 carriers with spacing of 300 kHz in the 1895–1918.1 MHz band, the upper half of which is used for public systems and the lower half for home office applications. PHS divides the band into 75 carriers spaced at 300 kHz, each of which supports four channels through time division multiple access (TDMA) and time division duplex (TDD). PHS employs /4 differential quaternary phase shift keying ( /4 DQPSK) to yield a theoretical data rate of 384 kbps per carrier.Voice is encoded at 32 kbps through adaptive differential pulse code modulation (ADPCM). See also ADPCM, carrier, channel, cordless telephone, /4 DQPSK, TDD, and TDMA. |