Beacon · τ/31–47 Workbench

Prime preambles · Golay(24,12,8) header · RS(31,19) descriptor · CRC‑16 · deep‑link · low‑SNR audio plant
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31 ↔ 47 bridge ready

1) Preamble · prime length

Auto: 31→mseq, 47→Legendre Corr: —
Autocorrelation shown as max sidelobe (periodic). ±1 symbols recommended for BPSK audio plants.

2) Control Header → Golay(24,12,8)

Raw 12‑bit header (v|topo|tid|lane)
Golay(24,12,8) codeword (23b Golay + even parity)
We implement the standard (23,12,7) Golay by polynomial division, then append a single even parity bit to form (24,12,8).

3) Descriptor → CRC‑16 → RS(31,19) over GF(32)

Descriptor bits (pre‑CRC)
CRC‑16/CCITT (poly 0x1021), appended MSB→LSB

Data symbols (5‑bit, padded to 19)
Parity symbols (12)
Codeword (31 symbols) · hex
GF(32) uses primitive polynomial x⁵+x²+1 and generator roots α¹…α¹². Data shorter than 19 symbols is zero‑padded.

4) Assembly (pre‑/post‑ECC)

Use pre‑ECC bits when testing symbolization; use post‑ECC when planting full frames in controlled channels.

5) Audio Plant (low‑SNR BPSK) · experimental

Download
We BPSK‑map ±1 symbols to {−A,+A}, embed under white noise σ, and export 16‑bit PCM WAV. Defaults plant at <5σ.