docs: spec ALC tolerance workstream#31
Merged
Merged
Conversation
The modem has zero validation that it tolerates HF transmitter ALC
compression. OTASim has only AWGN + Watterson; cable rig has no radio;
no CTest gate exercises compression; no invariant. The only ALC
exposure was KC3VPB's 2026-05-07 OTA where decode was poor and the
response was to pre-attenuate the WAV (which KC3VPB pushed back on
the next day — "design for ALC, don't dodge it").
Until this workstream lands, "does the modem work on a real radio"
is a guess.
Adds:
- docs/ALC_TOLERANCE_WORKSTREAM.md — full spec. Two pieces: (1) an
AlcCompressor channel-model node in OTASim (peak detect + exp
attack/release in dB, configurable threshold/ratio/attack/release,
optional overshoot transient) wired before channel noise in the
mixer chain; (2) a decoder tolerance sweep across the production
mode ladder (DQPSK R1/4 to D8PSK R2/3) at compression ratios
{1:1, 2:1, 4:1, 8:1, infinity:1} and drives {threshold, +6 dB,
+12 dB}, baseline table committed as a regression gate. Includes
milestones (~3 dev-days to M4) and explicit anti-scope (no
PAPR-reduction work, no default tx_drive tweaks, hard stop if
DQPSK R1/2 fails at 4:1 / +6 dB).
- docs/AGENT_TASK_BACKLOG.md — entry D3 under Lane D (fading
robustness) cross-referencing the spec, with acceptance criteria
and gate command for an autonomous agent to pick up.
No code changes. Docs only.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Docs-only. Specs out the ALC tolerance workstream so a future agent
or maintainer can pick it up cleanly.
Why now: the modem has zero validation that it decodes through
HF transmitter ALC compression. OTASim is AWGN + Watterson only;
cable rig has no radio; no CTest gate; no invariant. KC3VPB's
2026-05-08 operator pushback ("design for ALC, don't dodge it") was
about exactly this and we never followed through.
What lands:
`docs/ALC_TOLERANCE_WORKSTREAM.md` — full spec covering the
`AlcCompressor` channel-model node (peak detect + exp attack/
release in dB, threshold/ratio/attack/release/overshoot config),
wiring into the OTASim mixer chain BEFORE channel noise, and a
decoder tolerance sweep over the production mode ladder at
realistic compression ratios. Includes milestones, three-perspective
check, anti-scope, references.
`docs/AGENT_TASK_BACKLOG.md` — new entry D3 under Lane D
cross-referencing the spec with acceptance criteria and gate
command.
Anti-scope (explicit):
baseline tolerance numbers exist.
the production-baseline tripwire.
Test plan
🤖 Generated with Claude Code