摘要 |
An initial acquisition technique for a time division multiple access (TDMA) communication system, employing an access signal of a frequency varying periodically in a predetermined relation to the TDMA time frame. Means are provided for detecting when the frequency of the signal as relayed back to the accessing station is at a predetermined value or within a predetermined frequency band to obtain the desired transmission timing information without necessitating use of any automatic frequency control means despite any deviation in the central frequency of the signal occurring during its travel. |