| Communications Blockset | |
Library
FM, in Digital Baseband sublibrary of Modulation
Description 
The M-FSK Demodulator Baseband block demodulates a signal that was modulated using the M-ary frequency shift keying method. The input is a baseband representation of the modulated signal. The input and output for this block are discrete-time signals. The input can be either a scalar or a frame-based column vector.
The M-ary number parameter, M, is the number of frequencies in the modulated signal. The Frequency separation parameter is the distance, in Hz, between successive frequencies of the modulated signal.
Binary or Integer Outputs
If the Output type parameter is set to Integer, then the block outputs integers between 0 and M-1.
If the Output type parameter is set to Bit and the M-ary number parameter has the form 2K for some positive integer K, then the block outputs binary representations of integers between 0 and M-1. It outputs a group of K bits, called a binary word, for each symbol.
In binary output mode, the Symbol set ordering parameter indicates how the block maps an integer to a corresponding group of K output bits. See the reference pages for the M-FSK Modulator Baseband and M-PSK Modulator Baseband blocks for details.
Whether the output is an integer or a binary representation of an integer, the block maps the highest frequency to the integer 0 and maps the lowest frequency to the integer M-1. In baseband simulation, the lowest frequency is the negative frequency with the largest absolute value.
Processing an Upsampled Modulated Signal
The input signal can be 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
| | Memoryless Nonlinearity | M-FSK Demodulator Passband | |
