| 摘要 |
A time-sharing subscriber communications system wherein a time-division multiplexed signal having a series of frames and a predetermined number of time slots in each frame is transmitted in a given frequency band over a single wideband circuit to a plurality of subscriber terminals. Various time slots contain information from various input channels which are respectively related to various ones of the subscriber terminals. The transmitted signal is modulated by a zero axis crossing modulation scheme wherein each time slot is defined by the interval between successive zero axis crossings and the information contained in each time slot is defined by the duration of the time slot. At each subscriber terminal the information related to that channel is tapped off from the signal received from the transmitter terminal, a portion of the received signal is retransmitted over the wideband circuit and new information related to the subscriber terminal is newly transmitted in one or more time slots of each frame of the time-division multiplexed signal. A receiver terminal, interfaced to the opposite end of the wideband circuit from the transmitter terminal, demodulates the newly transmitted information from the subscriber terminal and provides output signals to various output channels respectively related to various ones of the subscriber terminals.
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