{
  "aliases": [
    "LLR"
  ],
  "note": "For the NAND convention log(P(bit=0 | observation) / P(bit=1 | observation)), a positive value favors zero; reversing the ratio reverses its sign.",
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "related": [
    "ldpc",
    "soft-decision-decoding"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "slug": "log-likelihood-ratio",
  "term": "Log-likelihood ratio",
  "definition": "A log-likelihood ratio is the logarithm of the relative likelihood of two alternatives, used in decoding to express a bit decision and its confidence.",
  "citations": [
    {
      "id": "cai2017",
      "title": "Cai, Ghose, Haratsch, Luo and Mutlu. Error Characterization, Mitigation, and Recovery in Flash Memory Based Solid-State Drives. Author manuscript arXiv:1706.08642, 2017, sections 6.2-6.3.",
      "url": "https://arxiv.org/abs/1706.08642",
      "accessed": "2026-10-11"
    },
    {
      "id": "hesela-ldpc",
      "title": "Hesela: LDPC in NAND, the read cost of confidence",
      "url": "https://hesela.com/analyses/ldpc-soft-decoding-read-cost/",
      "accessed": "2026-10-11"
    }
  ]
}