Frequency shift keying (FSK) is a form of frequency modulation for a discrete signal. The different values of the signal are represented by the different values of the carrier wave. The frequency of the carrier waves, as it were, contributes to the value of the signal. The simplest form is for a digital signal with possible values of only 0 and 1. The frequency of the signal shifts back and forth of the frequency for displaying a 0 and the frequency for displaying a 1.
The figure below shows an FSK modulated signal: the carrier frequency changes from one value to another. In order to keep the bandwidth as small as possible, you can also choose to make the transition progressively.
Thus, FSK is involved in the carrier wave process. For applications where this is not possible, or complicated, it is also used by AFSK. Programmavoorbeeld
PowerBASIC or clone program. FUNCTION PBMAIN AS LONG LOCAL draaggolf AS SINGLE LOCAL MODULATION AS SINGLE LOCAL i AS LONG pi## = 3.141592653589793## OPEN $file FOR OUTPUT AS #1 FOR i = 0 TO 3600 STEP 1 draaggolf = pi## / 180 * i IF i / 720 = INT (i / 720) THEN modulation = 1 modulation 'switch between freq. x $ = FORMAT $ (I & amp;, "* 0") + "," + FORMAT $ (SIN (carrier wave * (1 + modulation)), "* 0.000") PRINT x$ PRINT #1, x$ NEXT i CLOSE #1 END FUNCTION Also see
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