| 摘要 |
HOMODYNE-TYPE SPREAD SPECTRUM TRANSMITTER/RECEIVER The present invention relates to a homodyne-type spread spectrum transmitter and an associated remote spread spectrum receiver which communicate with each other by the transmission of both (1) a spread spectrum Pseudo Noise Code (PNC) sequence signal, and (2) a combined PNC sequence plus the data information (PNC+data) signal. The two signals can be transmitted concurrently using either different frequency bands or on a quadrature carrier; or the two signals can be transmitted with a time offset between signals. At the receiver the PNC and the PN+data signals are separately recovered for the case of the concurrent transmission techniques, anddirectly mixed to despread the received signal and recover the data signal at baseband. For the time offset technique, the delay provided in one of the time offset signals is again introduced to the previously delayed signal, and the delayed and undelayed signal portions of the received combined signal are directly mixed and then low pass filtered to recover the data signal. Such techniques eliminate the necessity for providing PNC acquisition and tracking circuits in associated spread spectrum transmitter and receiver combinations. |
