mirror of
https://git.vladimir.cc/vladimir/ewsdr.git
synced 2026-08-25 18:43:51 +00:00
ew8bakandClaude Opus 4.8
afc8775ddb
Full chain now decodes the QO-100 central beacon to 256-byte AO-40 frames on-air (frames>0, RS errors=0). Builds on M1 (stable BPSK demod). FEC backend (BeaconFEC.pas, TBeaconFEC): - AO-40 FEC: distributed sync (65 bit, step 80) -> 80x65 deinterleave -> Viterbi r=1/2 k=7 -> CCSDS descramble -> 2x RS(160,128). Links system libfec (Karn) load-time (libfec.so/.dll/.dylib). Viterbi AO-40 [0x4F,-0x6D] remapped to libfec [0x6D,0x4F]. Validated against gr-satellites reference vectors (fectest2: exact 256-byte frame, 0 mismatches). DBPSK Manchester frontend (BeaconDecoder.pas): - Chip-rate (800) processing: RRC matched filter -> ML signal-times-slope timing recovery -> Costas -> Manchester combine (block phase select) -> differential decode -> soft symbols to FEC. - Carrier acquisition: squaring-FFT estimates the residual (carrier at +-pi/chip defeats decision-directed Costas), one-shot pulls it to DC via residual NCO. - Costas frequency offload into pre-RRC NCO (with deadband) tracks LNB drift without hitting the +-pi Costas clamp. - ML TED replaces Gardner, which degenerates on the Manchester chip stream. Temporary on-air diagnostics retained (IQ dump + STATE log) pending wider signal validation; to be removed before final cleanup. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>