| 摘要 |
FSK signals in a digital sense are obtained from a memory comprising a table of forty numbers, representing amplitudes of points in one cycle of a sine wave, the points being separated by equal phase angles. A processor reads out, at a fixed rate, the numbers corresponding to each tenth or each eleventh point in accordance with the condition of an incoming binary signal, whereby the output numbers represent a frequency-shift wave. Digital circuitry is used and the modulator may be time shared by a plurality of data sources.
|
