Initial Galileo receiver and SignalSim integration

tests/integration/test_fixed_acquisition.py

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+import numpy as np
+
+from galileo_rx.fixed_point.bittrue_pipeline import compare_acquisition, sweep_acquisition_word_lengths
+from galileo_rx.fixed_point.fixed_acquisition import FixedPcpsAcquisition
+
+
+def test_fixed_acquisition_peak_agrees_with_float() -> None:
+    rng = np.random.default_rng(4)
+    count = 256
+    fs = 1.024e6
+    replica = np.where(rng.integers(0, 2, count), 1.0, -1.0)
+    delay = 73
+    doppler = 4000.0
+    time_s = np.arange(count) / fs
+    samples = np.roll(replica, delay) * np.exp(2j * np.pi * doppler * time_s)
+    bins = np.asarray([-4000.0, 0.0, 4000.0])
+    reference = np.asarray([
+        np.abs(np.fft.ifft(np.fft.fft(samples * np.exp(-2j * np.pi * frequency * time_s)) * np.conjugate(np.fft.fft(replica)))) ** 2
+        for frequency in bins
+    ])
+    fixed = FixedPcpsAcquisition().search(samples, replica, fs, bins)
+    comparison = compare_acquisition(reference / count**2, fixed, threshold=2.5)
+    assert comparison.doppler_bin_agreement
+    assert comparison.code_phase_agreement
+    assert comparison.acquisition_decision_agreement
+
+
+def test_word_length_sweep_reports_each_width() -> None:
+    rng = np.random.default_rng(7)
+    replica = np.where(rng.integers(0, 2, 64), 1.0, -1.0)
+    reports = sweep_acquisition_word_lengths(np.roll(replica, 9).astype(complex), replica, 1e6, np.asarray([0.0]), [6, 8])
+    assert [item["input_bits"] for item in reports] == [6, 8]
+    assert all(item["code_phase_agreement"] for item in reports)