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Thus, the maximum frequency deviation is δ = 0.5 f m where f m is the maximum modulating frequency. As a result, the modulation index m is 0.5. This is the smallest FSK modulation index that can be chosen such that the waveforms for 0 and 1 are orthogonal. A variant of MSK called Gaussian minimum-shift keying (GMSK) is used in the GSM mobile ...
In addition to Gaussian minimum-shift keying (GMSK), EDGE uses higher-order PSK/8 phase-shift keying (8PSK) for the upper five of its nine modulation and coding schemes. EDGE produces a 3-bit word for every change in carrier phase. This effectively triples the gross data rate offered by GSM.
Minimum frequency-shift keying or minimum-shift keying (MSK) is a particular spectrally efficient form of coherent FSK. In MSK, the difference between the higher and lower frequency is identical to half the bit rate. Consequently, the waveforms that represent a 0 and a 1 bit differ by exactly half a carrier period.
ASK (amplitude-shift keying): a finite number of amplitudes are used. QAM (quadrature amplitude modulation) : a finite number of at least two phases and at least two amplitudes are used. In QAM, an in-phase signal (or I, with one example being a cosine waveform) and a quadrature phase signal (or Q, with an example being a sine wave) are ...
GMSK is based on two ideas: one is shaping of data pulses with gaussian filter, the other is FSK. MSK uses index that is much lower than indices for FSK. There is no rule that it has to be 0.5 or 0.25. Anything "low enough" is good enough to rename FSK as MSK. Such modulation has very different spectrum so that it may be distinguished from FSK.
AIS messages are transmitted using Gaussian minimum-shift keying (GMSK) modulation. The GMSK modulator BT-product used for transmission of data should be 0.4 maximum (highest nominal value). The GMSK coded data should frequency modulate the VHF transmitter. The modulation index should be 0.5. The transmission bit rate is 9600 bit/s
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Minimum-shift keying#Gaussian minimum-shift keying To a section : This is a redirect from a topic that does not have its own page to a section of a page on the subject. For redirects to embedded anchors on a page, use {{ R to anchor }} instead .