Add optimize_alpha() function that sweeps hardware-friendly alpha
values to find the best DE threshold with normalized min-sum.
Add alpha-sweep CLI subcommand and --z/--cn-mode/--alpha options
to the full pipeline.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Thread cn_mode and alpha parameters through the entire DE pipeline:
de_cn_update_vectorized(), density_evolution_step(), run_de(),
compute_threshold(), and compute_threshold_for_profile().
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add cn_mode ('offset'/'normalized') and alpha parameters to
min_sum_cn_update() in ldpc_sim.py and generic_decode() in
ldpc_analysis.py. Normalized mode scales magnitudes by alpha
(default 0.75) instead of subtracting a fixed offset, which
is better suited for low-rate codes.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
