Howtosignalprocessing
- What is demodulation of FSK?
- Why FSK is not suitable for high speed modem?
- What is the most commonly used demodulation technique for FSK?
What is demodulation of FSK?
An FSK demodulator is provided comprising means for receiving and digitizing an FSK signal (such as a signal comprising two frequencies f1 and f2 in which first and second logic states are represented by first and second periods of different durations).
Why FSK is not suitable for high speed modem?
FSK modems are inefficient in their use of bandwidth, with the result that the maximum data rate over normal telephone lines is 1800 bps. Typically, for rates over 1200 bps, other modulation schemes are used.
What is the most commonly used demodulation technique for FSK?
The most used demodulation technique is the one using a PLL circuit (fig. 2). The FSK signal across the PLL input takes two frequency values. The error voltage supplied by the phase comparator follows such variations, and so, it constitutes the NRZ binary representation (high and low level) of the FSK input signal.
