Article

Coding Techniques for Partial-Response Channels

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Abstract

A coding technique for improving the reliability of digital transmission over noisy partial-response channels with characteristics (± D <sup>m</sup>), m =1, 2, where the channel input symbols are constrained to be ±1, is presented. In particular, the application of a traditional modulation code as an inner code of a concentrated coding scheme in which the outer code is designed for maximum (free) Hamming distance is considered. A performance comparison is made between the concentrated scheme and a coding technique presented by Wolf and G. Ungerboeck (see ibid., vol. COM-34, p.765-773, Aug. 1986) for the dicode channel with transfer function (1- D )

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... The code-efficiency can be expressed in terms of the code-rate R. The asymptotic coding gain GD is now defined as GD = Rdb(coded) db(uncoded) . This equality indicates the saving in required energy-per-bit to noise-power-density ratio of the coded scheme relative to the uncoded case [44]. ...
Chapter
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Continuous phase modulation-Part 11: Partial response signaling QP, an improved code for high density digital recording
  • T Aulin
  • N Rydbeck
  • C E Sundberg
T. Aulin, N. Rydbeck, and C. E. Sundberg, " Continuous phase modulation-Part 11: Partial response signaling, " ZEEE Truns. Corn-mun., vol. COM-29, pp. 210-225, Mar. 1981. J. A. Bixby and R. A. Ketcham, " QP, an improved code for high density digital recording, " IEEE Trans. Magn., vol. MAG-15, pp. pp. 1557-1569, NOV. 1986. 1465-1467, NOV. 1979.