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Speed up carrier detection with numpy.

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Julien Woillez
2018-07-22 16:46:55 +00:00
parent ac2e66bddd
commit 53df2d5934
1 changed files with 4 additions and 6 deletions
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10
amodem/detect.py
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@@ -85,12 +85,10 @@ class Detector(object):
signal = np.concatenate([zeroes, carrier])
signal = (2 ** 0.5) * signal / dsp.norm(signal)
coeffs = []
for i in range(len(buf) - len(signal)):
b = buf[i:i+len(signal)]
norm_b = dsp.norm(b)
c = (np.abs(np.dot(b, signal)) / norm_b) if norm_b else 0.0
coeffs.append(c)
corr = np.abs(np.correlate(buf, signal))
norm_b = np.sqrt(np.correlate(np.abs(buf)**2, np.ones(len(signal))))
coeffs = np.zeros_like(corr)
coeffs[norm_b > 0.0] = corr[norm_b > 0.0] / norm_b[norm_b > 0.0]
index = np.argmax(coeffs)
log.info('Carrier coherence: %.3f%%', coeffs[index] * 100)