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import numpy as np
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def generateAMSine(fs, toneFreq, numSamples, amplitude):
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step = (float(toneFreq) / float(fs)) * 2.0 * np.pi
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phaseArray = np.array(range(0,numSamples)) * step
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#e^(j*theta) = cos(theta) + j * sin(theta)
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wave = np.exp(1.0j * phaseArray) * amplitude
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return wave
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class OOKModulator:
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def __init__(self, baseband_samplerate, am_frequency):
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self.baseband_samplerate = baseband_samplerate
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self.am_frequency = am_frequency
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self.samples = generateAMSine(self.baseband_samplerate, 0, 1000, 0)
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def addPadding(self, uSDuration):
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sampleCount = int((uSDuration / 1000000.0) * self.baseband_samplerate)
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self.samples = np.append(self.samples, generateAMSine(self.baseband_samplerate, 0, sampleCount, 0))
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def addModulation(self, uSDuration):
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sampleCount = int((uSDuration / 1000000.0) * self.baseband_samplerate)
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self.samples = np.append(self.samples, generateAMSine(self.baseband_samplerate, self.am_frequency, sampleCount, 1))
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def getSamples(self, numpyType):
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self.addPadding(1000)
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return self.samples.astype(numpyType)
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def getSamplesAndReset(self, numpyType):
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self.addPadding(1000)
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returnSamples = self.samples.astype(numpyType)
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self.samples = generateAMSine(self.baseband_samplerate, 0, 1000, 0)
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return returnSamples
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