Weak-Signal Engineering is a 14-part deep dive into the marginal regime — the space between full quieting and no signal, where a receiver locks but doesn’t decode, and where most real traffic actually lives. Across one year of issue-tracker work, GopherTrunk roughly doubled its decode yield there with four levers: blind equalization (CMA with frozen snapshots), trained equalization (LMS on known midambles), soft-decision FEC, and diversity combining. This series is the cross-protocol theory and engineering of those levers — what each one can and cannot fix, the traps between them, and the tests that keep them honest.

Where SDR Internals gave equalization and diversity one survey episode, this series goes lever by lever. The concurrent TETRA End to End series is its flagship case study, and The Analog Edge covers the other side of the ADC — because the first weak-signal question is always whether the deficit is in the channel or baked into the samples. One discipline runs the length of the series: CRC-valid frames are the only trustworthy verdict; EVM, SNR and constellation beauty are advisory at best and traps at worst.

Every post reads three ways: a TL;DR + cheat-sheet for skimmers, bold headers, tables, and diagrams for the medium read, and full prose with real code for the deep read.

New here? Start with the DSP learning module for the vocabulary, then come back for the engineering.<p class="post-list__empty">No posts in this series yet — check back soon.</p><p class="blog-feed-link"> See all deep dives or subscribe via RSS. </p>