MFSK waveform
The multiple frequency shift keying (MFSK) waveform is used in automotive radar to improve simultaneous range and Doppler estimation of multiple targets. TheMFSKWaveform
System object™ creates the baseband representation of an MFSK waveform. An MFSK waveform consists of two interleaved sequences of increasing frequencies, as described inAlgorithms.
To obtain waveform samples:
Define and set up the MFSK waveform. SeeConstruction.
Callstep
to generate the MFSK waveform samples according to the properties ofphased.MFSKWaveform
. The behavior ofstep
is specific to each object in the toolbox. The output of thestep
method is controlled by theOutputFormat
property, which has no effect on the properties of the waveform.
Note
Starting in R2016b, instead of using thestep
方法来执行操作defined by the System object, you can call the object with arguments, as if it were a function. For example,y = step(obj,x)
andy = obj(x)
perform equivalent operations. When the only argument to thestep
method is the System object itself, replacey = step(obj)
byy = obj()
.
sMFSK = phased.MFSKWaveform
creates an MFSK waveform System object,sMFSK
.
creates an MFSK waveform object,sMFSK
= phased.MFSKWaveform(Name,Value
)sMFSK
, with additional properties specified by one or moreName-Value pair
arguments.Name
must appear inside single quotes (''
). You can specify several name-value pair arguments in any order asName1,Value1,…,NameN,ValueN
.
plot | Plot continuous MFSK waveform |
reset | Reset states of the MFSK waveform object |
step | Samples of continuous MFSK waveform |
Common to All System Objects | |
---|---|
release |
Allow System object property value changes |
An MFSK waveform consists of two interleaved stepped-frequency sequences, as shown in this time-frequency diagram.
Each sequence is a set of continuous waveform (CW) signals increasing in frequency. The offset,Foffset, between the two sequences is constant and can be positive or negative. A complete waveform consists of an even number of steps,N, of equal duration,Tstep. Then, each sequence consists ofN/2steps. The sweep frequency,Fsweep, is the difference between the lowest and highest frequency of either sequence.Fsweepis always positive, indicating increasing frequency. The frequency difference between successive steps of each sequence is given by
Fstep=Fsweep/(N/2–1).
Signal Parameter | Property |
---|---|
Fsweep | 'SweepBandwidth' |
Tstep | 'StepTime' |
N | 'StepsPerSweep' |
Foffset | 'FrequencyOffset' |
[1] Meinecke, Marc-Michale, and Hermann Rohling, “Combination of LFMCW and FSK Modulation Principles for Automotive Radar Systems.”German Radar Symposium GRS2000.2000.
[2] Rohling, Hermann, and Marc-Michale Meinecke. “Waveform Design Principles for Automotive Radar Systems”.CIE International Conference on Radar. 2001.
phased.FMCWWaveform
|phased.LinearFMWaveform
|phased.MatchedFilter
|phased.PhaseCodedWaveform
|phased.RectangularWaveform
|phased.SteppedFMWaveform