| Communications Blockset | |
Modulate using the Gaussian minimum shift keying method
Library
CPM, in Digital Baseband sublibrary of Modulation
Description 
The GMSK Modulator Baseband block modulates using the Gaussian minimum shift keying method. The output is a baseband representation of the modulated signal.
The BT product parameter represents bandwidth multiplied by time. This parameter is a nonnegative scalar. It is used to reduce the bandwidth at the expense of increased intersymbol interference. The Pulse length parameter measures the length of the Gaussian pulse shape, in symbol intervals. For the exact definitions of the pulse shape, see the work by Anderson, Aulin, and Sundberg listed in References.
The Symbol prehistory parameter is a scalar or vector that specifies the data symbols used before the start of the simulation, in reverse chronological order. If it is a vector, then its length must be one less than the Pulse length parameter.
In this block, a symbol of 1 causes a phase shift of 
/2 radians. The Phase offset parameter is the initial phase of the output waveform, measured in radians.
Input Attributes
The input can be either a scalar or a frame-based column vector. If the Input type parameter is set to Integer, then the block accepts values of 1 and -1. If the Input type parameter is set to Bit, then the block accepts values of 0 and 1.
Upsampling the Modulated Signal
This block can output an upsampled version of the modulated signal. The Samples per symbol parameter is the upsampling factor. It must be a positive integer. For more information, see Upsampled Signals and Rate Changes in Using the Communications Blockset.
Dialog Box
Pair Block
See Also
References
[1] Anderson, John B., Tor Aulin, and Carl-Erik Sundberg. Digital Phase Modulation. New York: Plenum Press, 1986.
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