SPREAD SPECTRUM COMMUNICATION EQUIPMENT

PURPOSE: To attain multiplex communication without increasing the number of PN code generating circuits. CONSTITUTION: When a reception section 150 of a transmitter-receiver 10 is disabled for reception, a synchronization detection circuit 130 gives information not establishing the synchronization to a control signal generating section 160. The generating section 160 generates a control signal varying the phase and sends it to a control signal multiplexer circuit 100, which sends the control signal to a transmitter-receiver 20 together with the information signal. Since one transmission signal is given to a reception section 220, the reception synchronization is immediately established. A control signal demultiplexer circuit 232 demultiplexes the control signal from the reception signal demodulated with synchronization establishment to send a signal to control a phase to a phase control section 270, which controls a phase variable circuit 210b to shift the phase of the clock signal. An absolute phase difference is produced in a PN code sent from the transmitter-receiver 20 before and after the control and a relative phase difference is produced between plural PN codes reaching a reception point of the transmitter-receiver 10. When there is a relative phase difference over one tip between the PN codes, the reception synchronization is established for the transmitter-receiver 10.