{
  "status": "unknown",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-20",
  "slug": "partial-response-target",
  "term": "Partial-response target",
  "aliases": [
    "PR equalization target",
    "partial-response channel target"
  ],
  "definition": "A partial-response target specifies the desired sampled channel response, including controlled contributions from neighboring symbols, used by an equalizer and sequence detector.",
  "note": "With D denoting one channel-symbol delay, PR4 is 1 - D^2 and EPR4 is 1 + D - D^2 - D^3 [kobayashi2009]. The target describes signal-amplitude arithmetic, not binary XOR.\n\nUmemoto's PR5 proposal uses -1 + 2D^2 - D^4 for a particular single-layer perpendicular recording configuration [umemoto1997]. These targets are distinct responses within this concept, not aliases for interchangeable implementations.\n\nA target alone does not specify the noise model, detector, constrained code or error-correction stage. State counts must name their trellis and sampling convention.",
  "related": [
    "prml-encoding",
    "npml-detection",
    "intersymbol-interference",
    "pmr"
  ],
  "citations": [
    {
      "id": "kobayashi2009",
      "title": "H. Kobayashi, PRML historical review, IEEE Communications Magazine 47(3), 14-17 (2009), full text",
      "url": "https://hp.hisashikobayashi.com/wp-content/uploads/2015/12/PRML-IEEE-Comm_Magazine.pdf",
      "accessed": "2026-10-20"
    },
    {
      "id": "umemoto1997",
      "title": "M. Umemoto, PR5ML Processing for Perpendicular Magnetic Recording (1997), section II and Table 1, full text",
      "url": "https://www.jstage.jst.go.jp/article/jmsjmag/21/S_2_PMRC_97_2/21_S_2_PMRC_97_2_S2_395/_pdf",
      "accessed": "2026-10-20"
    }
  ]
}