Goon-Strat

Phase 2 Plan: Signal and Decoding (Gateways 4-6)

Scope

• Gateway 4: signal generation and output formatting
• Gateway 5: synchronization and decoding
• Gateway 6: message parsing and timing reconstruction

Objectives

• Produce standards-aligned baseband I/Q signals from encoded frame content.
• Recover data reliably through synchronization, deinterleaving, decoding, and CRC checks.
• Parse recovered subframes into structured navigation outputs with correct timing fields.

Why This Phase Depends On Phase 1

• Signal-generation correctness depends on stable frame and code artifacts from Gateways 1-3.
• Decoder reliability depends on exact encoder and framing semantics; this phase validates round-trip behavior.

Workstreams

1. I/Q synthesis and file-format compliance
2. Frame synchronization and decoder pipeline
3. Message parser and field extraction
4. End-to-end round-trip validation

Week-by-Week Plan

Weeks 9-10 (Gateway 4)

• Engineer A + Developer B
  • Implement AFS-I/AFS-Q modulation flow with required chip and symbol rates.
  • Verify mapping against signal parameters and file format headers.
• Engineer B + Developer C
  • Validate generated I/Q output dimensions, sample type, and timing alignment.
  • Benchmark generation latency and memory behavior.
• Engineer C + Developer A
  • Prepare interoperability-ready I/Q artifact package and metadata templates.

Exit criteria:

• I/Q output files conform to expected headers and sample formats.
• Symbol/chip timing alignment validated.
• Signal generation metrics recorded and reviewable.

Weeks 11-12 (Gateway 5)

• Engineer A + Developer C
  • Implement sync detection and frame lock behavior for valid and degraded signals.
  • Implement deinterleaving and LDPC/BCH decode pipeline.
• Engineer B + Developer A
  • Validate decode reliability and BER behavior at target SNR profiles.
  • Build failure-injection and recovery tests for decode edge conditions.
• Engineer C + Developer B
  • Build decode artifact exchange loop and discrepancy reporting workflow.

Exit criteria:

• Reliable frame detection and lock performance.
• Decoded outputs pass CRC and structure validations.
• BER and decode thresholds measured against requirement targets.

Weeks 13-14 (Gateway 6)

• Engineer A + Developer B
  • Implement parser for WN, ITOW, TOI, and subframe payload extraction.
  • Validate bit-offset and field-width correctness against table definitions.
• Engineer B + Developer C
  • Build parser conformance tests and malformed-payload rejection tests.
  • Add timing-reconstruction consistency checks.
• Engineer C + Developer A
  • Generate parser-level JSON outputs for interoperability replay and review.

Exit criteria:

• Parsed message fields are complete and consistent.
• Timing reconstruction is validated against expected formulas.
• Parser outputs are reproducible and exchange-friendly.

Risks and Mitigations

• Risk: decode instability under noisy conditions
  • Mitigation: threshold tuning with controlled SNR test sweeps and replayable fixtures.
• Risk: parser misalignment with frame bit layout
  • Mitigation: explicit offset tests using sb2_bit_layout.csv and Table 14 constants.

Phase 2 Definition of Success

• Gateways 4-6 complete with successful encode-to-decode-to-parse round-trip evidence.
• Signal, decoding, and parser outputs are reproducible and ready for integration-level evaluation.

⬆️ Back to Top ⬆️

---

Back Page

Next Page