comm.FMBroadcastModulator
Modulate broadcast FM audio signal
Description
Thecomm.FMBroadcastModulator
System object™ pre-emphasizes an audio signal and modulates it onto a baseband FM signal. For more information, see theAlgorithmssection.
To modulate a broadcast FM audio signal:
Create the
comm.FMBroadcastModulator
object and set its properties.Call the object with arguments, as if it were a function.
To learn more about how System objects work, seeWhat Are System Objects?
Creation
Syntax
Description
creates a FM broadcast modulator System object.fmbmodulator
= comm.FMBroadcastModulator
sets properties using one or more name-value arguments. For example,fmbmodulator
= comm.FMBroadcastModulator(Name
,Value
)'SampleRate',400e3
specifies a sample rate of 400 kHz.
sets properties based on configuration of the inputfmbmodulator
= comm.FMBroadcastModulator(fmbdemodulator
)comm.FMBroadcastDemodulator
System object,fmbdemodulator
.
Properties
Usage
Description
Input Arguments
Output Arguments
Object Functions
To use an object function, specify the System object as the first input argument. For example, to release system resources of a System object namedobj
, use this syntax:
release(obj)
Examples
Limitations
If you set the
RBDS
来true
, both the audio and RDS (or RBDS) inputs must satisfy this equation.The RDS (or RBDS) signal sample rate is
RBDSSamplesPerSymbol
×1187.5
Hz.The length of the input RDS (or RBDS) signal,
rbdssig
, must be an integer multiple of theRBDSDecimationFactor
property. The input length of the audio signal,audiosig
, must be an integer multiple of theAudioDecimationFactor
property. For more information onRBDSDecimationFactor
andAudioDecimationFactor
, see theinfo
object function.
Algorithms
References
[1]Hatai, I., and I. Chakrabarti. “A New High-Performance Digital FM Modulator and Demodulator for Software-Defined Radio and Its FPGA Implementation.”International Journal of Reconfigurable Computing(December 25, 2011): 1-10. https://doi.org/10.1155/2011/342532.
[2]Taub, H., and D. Schilling.Principles of Communication Systems. McGraw-Hill Series in Electrical Engineering. New York: McGraw-Hill, 1971, pp. 142–155.
[3]Der, Lawrence. "Frequency Modulation (FM) Tutorial".Silicon Laboratories Inc., pp. 4–8.