| 摘要 |
In a system for wireless transmission of telephone calls between a stationary unit 1, which is connected to a telephone line 2 and a portable wireless telephone apparatus 3 at a short distance from the stationary unit 1, all pairs of appliances 1, 3 have access to a number of shared duplex radio call channels for the transmission of calls and a shared radio signalling channel for the transmission of signals concerning connection and disconnection of the call channels. The radio call channels are allocated in accordance with adaptive channel seeking in that they are monitored before a call and a free channel is selected. A single call channel is used for both call directions, which is made possible by time sharing and time compression. The degree of time compression can be set independently of whether or not there are speech signals to send. The system's radio transmitters are designed to transmit either digital or analogue speech signals. The system's radio receivers are designed to work in accordance with the homodyne principle. <IMAGE>
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