Frequency shift keying

In many telemetry systems the PCM signal is frequency modulated on to a carrier wave. This is termed frequency shift keying (FSK). In other arrangements, the output of the transducer is converted into fixed step changes of the phase of the modulating signal. A device for this purpose is termed a modulator/demodulator or modem. 

We consider a number of orthogonal signaling formats— we begin with frequency shift keying (FSK) which is also referred to as PCM/FM. In such a scheme, the frequency of one of the transmitted beams is fixed at the value /j, while the frequency of the other is caused to shift between two values, /j and (not to be confused with the Doppler shiftedconsidered earlier). When a 1(0) is transmitted, the second carrier will be at frequency /ji/ ). The difference frequency will therefore shift between /c=/ —/i and fc=ft f2 (assuming /i The frequencies /i -/lI, IA-ZlI, and I/2-/2I will all lie within the... 

Biphase-shift keying (BPSK) Frequency-shift keying (FSK)... 

Fast frequency shift keying (FFSK) A system of digital modulation where the digits are represented by different frequencies that are related to the baud rate, and where transitions occur at the zero... 

Frequency shift keying (FSK) A commonly used method of digital modulation in which a one and a zero (the two possible states) are each transmitted as separate frequencies. 

The data interface link between the data acquisition/telemetry system and the CPIMS is achieved via a bidirectional frequency modulation (FM) transceiver. Encoded status messages which are generated by the data acquisition telemetry unit are transmitted via a Frequency Shift Keying (FSK) FM Radio Signal. This information is received at the... 

CPFSK Continuous Phase Frequency Shift Keying ... 

FFSK Fast Frequency Shift Keying = MSK NMT data and control... 

Neuromuscular prostheses and cochlear implants require higher data rate and power than artificial pacemakers. For neuromuscular prostheses, P. Troyk introduced frequency shift keying (FSK) [95], where two different frequencies of the carrier represent the binary data. The power signal serves as the data carrier, and an external Class-E amplifier sends the signal to increase the efficiency of power transfer. The data rate of this telemetry is 120 kbps modulated on 480 kHz that is power carrier frequency. For cochlear implants, several works have been discussing telemetry design [96-99], and amplitude shift keying (ASK) modulation, as an example, was used to transfer power and data to the implant in the ear [98]. The data rate is 400 kbps and it is modulated on 10-MHz power carrier frequency. 

Ghovanloo M, Najafi K (2004) A wideband frequency-shift keying wireless link for inductively powered biomedical implants. IEEE Trans Circ Syst. 51 2374-2383, Dec. 2004... 

---