CLOCK-001: validate independent-clock QPSK receiver

tests/test_clock001.py

@@ -0,0 +1,97 @@
+"""CLOCK-001: отдельная частота АЦП, строгий приём и область метрик."""
+
+from __future__ import annotations
+
+import math
+
+import numpy as np
+import pytest
+from scipy.ndimage import map_coordinates
+
+from protocol.video003_modem import SAMPLE_RATE_HZ
+from protocol.video005_receiver import IqStreamResult, receive_iq_stream
+from tools import clock001
+from tools.qpsk_rf_common import SEED, payload_for_sequence
+
+
+def test_sampling_rate_changes_time_base_and_keeps_cfo_independent() -> None:
+    tone_hz = 125_000
+    cfo_hz = 100
+    indexes = np.arange(200_000)
+    transmitted = np.exp(2j * np.pi * tone_hz * indexes / SAMPLE_RATE_HZ).astype(np.complex64)
+    for ppm in (-50, 0, 50):
+        received = clock001.sample_independent_clock(
+            transmitted, ppm, cfo_hz=cfo_hz, initial_phase_degrees=45,
+        )
+        scale = 1 + ppm * 1e-6
+        assert len(received) == math.floor((len(transmitted) - 1) * scale) + 1
+        measured_hz = (np.angle(np.vdot(received[:-1].astype(np.complex128),
+                                       received[1:].astype(np.complex128)))
+                       * SAMPLE_RATE_HZ / (2 * np.pi))
+        assert measured_hz == pytest.approx((tone_hz + cfo_hz) / scale, abs=0.2)
+        assert np.angle(received[0]) == pytest.approx(np.pi / 4, abs=1e-6)
+    assert clock001.payload_for_case(256, 7) == payload_for_sequence(SEED, 7)
+
+
+@pytest.mark.parametrize("ppm", (-50, 50))
+def test_long_packets_reacquire_and_decode_at_primary_limit(ppm: int) -> None:
+    fixture = clock001.build_fixture(1012)
+    received_iq = clock001.sample_independent_clock(fixture.iq, ppm)
+    result = receive_iq_stream(received_iq, decoder_backend="legacy")
+    summary = clock001.summarize_case(
+        result, fixture, sample_clock_offset_ppm=ppm, cfo_hz=0,
+        initial_phase_degrees=0, ebn0_db=None, receiver_time_s=1.0,
+        received_samples=len(received_iq),
+    )
+    assert summary["exact_packets"] == 3
+    assert summary["exact_sequences"] == [0, 1, 2]
+    assert summary["reacquisition_per_packet"] is True
+    assert summary["injected_timing_drift_across_packet_symbols"] == pytest.approx(-ppm * 1e-6 * 7572)
+
+
+@pytest.mark.parametrize("ppm", (-100, 100))
+def test_long_packet_stress_failure_is_not_declared_exact(ppm: int) -> None:
+    fixture = clock001.build_fixture(1012, packet_count=1)
+    received_iq = clock001.sample_independent_clock(fixture.iq, ppm)
+    result = receive_iq_stream(received_iq, decoder_backend="legacy")
+    summary = clock001.summarize_case(
+        result, fixture, sample_clock_offset_ppm=ppm, cfo_hz=0,
+        initial_phase_degrees=0, ebn0_db=None, receiver_time_s=1.0,
+        received_samples=len(received_iq),
+    )
+    assert summary["exact_packets"] == 0
+    assert summary["missing_sequences"] == [0]
+    assert summary["initial_timing_error_symbols_median"] is None
+    assert summary["final_timing_error_symbols_median"] is None
+    assert abs(summary["injected_timing_drift_across_packet_symbols"]) > 0.75
+
+
+def test_cubic_resampling_confirms_long_packet_stress_boundary() -> None:
+    """Проверяет вывод вторым интерполятором, без TX-подсказок приёмнику."""
+    fixture = clock001.build_fixture(1012, packet_count=1)
+    for ppm, expected_packets in ((-100, 0), (-50, 1), (50, 1), (100, 0)):
+        scale = 1 + ppm * 1e-6
+        count = math.floor((len(fixture.iq) - 1) * scale) + 1
+        positions = np.arange(count, dtype=np.float64) / scale
+        received_iq = (
+            map_coordinates(fixture.iq.real, [positions], order=3, mode="nearest")
+            + 1j * map_coordinates(fixture.iq.imag, [positions], order=3, mode="nearest")
+        ).astype(np.complex64)
+        result = receive_iq_stream(received_iq, decoder_backend="legacy")
+        assert len(result.packets) == expected_packets
+
+
+def test_reference_is_used_only_after_receiver(monkeypatch: pytest.MonkeyPatch) -> None:
+    fixture = clock001.build_fixture(256, packet_count=1)
+    calls = []
+
+    def fake_receiver(iq: np.ndarray) -> IqStreamResult:
+        calls.append(iq)
+        return IqStreamResult((), 0, 0, {})
+
+    monkeypatch.setattr(clock001, "receive_iq_stream", fake_receiver)
+    summary = clock001.evaluate_case(fixture, ppm=20)
+    assert len(calls) == 1
+    assert isinstance(calls[0], np.ndarray)
+    assert summary["exact_packets"] == 0
+    assert summary["missing_sequences"] == [0]