| 摘要 |
PURPOSE:To make small the size of transmission system, by making unnecessary the function of transmission and reception of ''data transmission request code''. CONSTITUTION:The start is requested to the transmission station 1a by the reception station 2x, the coding section 19 starts the operation with the start of transmission line between the network control sections 21 and 11, the scanning section 20 sequentially selects data, convertes 19 it into sequential serial pulse train, and modulates it into FS signal. In this case, the modulation center frequency of each data is selected every data depending on the selection signal of the coder 19 to be sequentially delivered to each reception station 2x... via the exchange network 3. The demodulation section 28 of the reception station 2x is set to the modulation center frequency fx for the demodulation center frequency, then the dats X only in FS signal transmitted is modulated, the seiral train obtained is decoded 26 to reproduce parallel data X. Thus, the hardware for the entire transmission system is reduced to make small the system size. |
