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86 lines
2.4 KiB
Python
86 lines
2.4 KiB
Python
import numpy as np
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import logging
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log = logging.getLogger(__name__)
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from . import common
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ALLOWED_EXCEPTIONS = (IOError, KeyboardInterrupt)
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def send(config, dst, src=None, verbose=False):
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calibration_symbols = int(1.0 * config.Fs)
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t = np.arange(0, calibration_symbols) * config.Ts
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signal = [np.sin(2 * np.pi * f * t) for f in config.frequencies]
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signal = common.dumps(np.concatenate(signal))
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try:
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while True:
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dst.write(signal)
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except ALLOWED_EXCEPTIONS:
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pass
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def run_recorder(config, recorder):
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frame_length = 200 * config.Nsym
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frame_size = frame_length * config.sample_size
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t = np.arange(0, frame_length) * config.Ts
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scaling_factor = 0.5 * len(t)
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carriers = [np.exp(2j * np.pi * f * t) for f in config.frequencies]
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carriers = np.array(carriers) / scaling_factor
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states = [True]
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errors = ['weak', 'strong', 'noisy']
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try:
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while True:
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data = recorder.read(frame_size)
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if len(data) < frame_size:
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return
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data = common.loads(data)
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frame = data - np.mean(data)
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coeffs = np.dot(carriers, frame)
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peak = np.max(np.abs(frame))
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total = np.sqrt(np.dot(frame, frame) / scaling_factor)
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max_index = np.argmax(np.abs(coeffs))
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freq = config.frequencies[max_index]
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rms = abs(coeffs[max_index])
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coherency = rms / total
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flags = [rms > 0.1, peak < 1.0, coherency > 0.99]
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states.append(all(flags))
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states = states[-2:]
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message = 'good signal'
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error = not any(states)
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if error:
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error_index = flags.index(False)
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message = 'too {0} signal'.format(errors[error_index])
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yield dict(
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freq=freq, rms=rms, peak=peak, coherency=coherency,
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total=total, error=error, message=message
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)
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except ALLOWED_EXCEPTIONS:
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pass
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fmt = '{freq:6.0f} Hz: {message:s}{extra:s}'
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fields = ['peak', 'total', 'rms', 'coherency']
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def recv(config, src, dst=None, verbose=False):
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extra = ''
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if verbose:
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extra = ''.join(', {0}={{{0}:.4f}}'.format(f) for f in fields)
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for result in run_recorder(config=config, recorder=src):
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msg = fmt.format(extra=extra.format(**result), **result)
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if not result['error']:
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log.info(msg)
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else:
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log.error(msg)
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