| 摘要 |
<p>A frequency multiplexed intercom system above baseband which uses a 2-wire cable as a bus (210) interconnecting a plurality of stations (200). Simultaneous conferencing among all stations is enabled by having each station modulate identical carrier waves. A reference frequency is made available on the frequency multiplexed bus so that each station can phase-lock its carrier wave generator (240) to an identical reference. Modulators (241) and demodulators (242) utilize phase-locked loops for frequency modulation and demodulation.</p> |
