| 摘要 |
A modem (18) and data communication system (10) particularly for operation in high frequency (HF) media. The modem (18) comprises an audio period timer (52) to detect cycles of data from a received signal, a bandwidth window (62) to flag undefined cycles UD so as to prevent such cycles UD from further influencing decoding decisions, a bit rate timer (57) to predict ends of bits of byte formed from a plurality of said cycles, a bit rate synchronisation means (76) to establish bit-wise synchronisation of the modem (18) with, the received signal, a byte synchronisation means to establish byte-wise synchronisation. |
