| 摘要 |
IN A COMMUNICATION SYSTEM INCLUDING AT LEAST ONE TRANSMITTER AND AT LEAST ONE RECEIVER, A FREQUENCY SYNCHONIZATION SIGNAL TRANSMITTED FROM THE TRANMITTER TO THE RECEIVER IS DETECTED. AN IN-PHASE COMPONENT OF A SIGNAL RECEIVED BY THE RECEIVER IS DELAYED, AND THE DELAYED IN-PHASE COMPONENT IS MULTIPLIED BY A QUADRATURE COMPONENT OF THE RECEIVED SIGNAL. THE STEPS OF DELAYING AND MULTIPLYING ARE REPEATED FOR A PREDETERMINED NUMBER OF SAMPLES OF THE RECEIVED SIGNAL TO PRODUCE AN ESTIMATED CROSS-CORRELATION VALUE. A DETERMINATION IS MADE WHETHER THE ESTIMATED CROSS-CORRELATION VALUE IS AT LEAST AS GREAT AS A PREDETERMINED THERESHOLD, INDICATING THAT THE TRANSMITTED SIGNAL IS A FREQUENCY SYNCHRONIZATION SIGNAL.FIG. 6
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