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61 lines
1.7 KiB
Python
61 lines
1.7 KiB
Python
import numpy as np
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import pytest
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from amodem import dsp
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from amodem import recv
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from amodem import train
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from amodem import sampling
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from amodem import config
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config = config.fastest()
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def test_detect():
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P = sum(train.prefix)
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t = np.arange(P * config.Nsym) * config.Ts
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x = np.cos(2 * np.pi * config.Fc * t)
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detector = recv.Detector(config)
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samples, amp = detector.run(x)
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assert abs(1 - amp) < 1e-12
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x = np.cos(2 * np.pi * (2*config.Fc) * t)
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with pytest.raises(ValueError):
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detector.run(x)
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with pytest.raises(ValueError):
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detector.max_offset = 0
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detector.run(x)
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def test_prefix():
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omega = 2 * np.pi * config.Fc / config.Fs
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symbol = np.cos(omega * np.arange(config.Nsym))
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signal = np.concatenate([c * symbol for c in train.prefix])
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def symbols_stream(signal):
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sampler = sampling.Sampler(signal)
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return dsp.Demux(sampler=sampler, omegas=[omega], Nsym=config.Nsym)
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r = recv.Receiver(config)
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freq_err = r._prefix(symbols_stream(signal))
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assert abs(freq_err) < 1e-16
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with pytest.raises(ValueError):
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silence = 0 * signal
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r._prefix(symbols_stream(silence))
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def test_find_start():
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sym = np.cos(2 * np.pi * config.Fc * np.arange(config.Nsym) * config.Ts)
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detector = recv.Detector(config)
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length = 200
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prefix = postfix = np.tile(0 * sym, 50)
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carrier = np.tile(sym, length)
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for offset in range(10):
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prefix = [0] * offset
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bufs = [prefix, prefix, carrier, postfix]
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buf = np.concatenate(bufs)
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start = detector.find_start(buf, length*config.Nsym)
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expected = offset + len(prefix)
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assert expected == start
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