| 摘要 |
A spread-spectrum transmitter and receiver using code division multiple access with time division multiple access technology for spread-spectrum communications. At a base station, a spread-spectrum transmitter includes a multiplexer for time multiplexing a synchronization-code signal and a plurality of data signals, which may be encoded as a plurality-encoded data signals, to generate a time-multiplexed signal. A chip-code generator generates a chip-code signal which is modulo added with the time-multiplexed signal by an EXCLUSIVE-OR gate to generate a spread-spectrum-time-multiplexed signal. A transmitter transmits the spread-spectrum-time-multiplexed signal over a communications channel. A spread-spectrum receiver at the base station processes a plurality of spread-spectrum signals, received from a plurality of remote units in as time division sequence of spread-spectrum signals, using a despreader circuit to generate a time-division signal. A demultiplexer demultiplexes the time-division signal as a plurality of data signals or as a plurality of privacy-encoded data signals. A remote unit, which may be a handset, includes a despreader circuit for despreading the spread-spectrum-time-multiplexed signal as a time-multiplexed signal. A synchronization-code matched filter detects the synchronization-code signal embedded in the time-multiplexed signal and thereby generates a timing signal. A controller uses the timing signal to generate a control signal. The control signal controls a transmit-receive switch for switching an antenna between the despreader circuit to the transmitter at the remote unit.
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