Pulse or digital communications – Receivers – Particular pulse demodulator or detector
Reexamination Certificate
1999-02-10
2003-07-29
Liu, Shuwang (Department: 2734)
Pulse or digital communications
Receivers
Particular pulse demodulator or detector
C375S229000, C375S232000, C714S769000
Reexamination Certificate
active
06600794
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a method as recited in the preamble of claim
1
. Maximum Likelihood Sequence Estimation is a powerful signal detection tool and can be theoretically proved to give optimum detection both for linear and for non-linear systems.
In high-density optical recording, because of high linear density and reduced track pitch, the signal read-out is not a linear process anymore. A linear process will then impose an upper limit on storage density and therefore a non-linear approach should be taken. MLSE, although optimal, is not a reasonably straightforward and efficient implementation because of its computational complexity. The inventors, on the basis of a study carried out on a Volterra model of the non-linear optical channel drawn by the Hopkins analysis, have taken an improved approach. In fact, they have recognized that first and second orders of signal distortion are mutually uncorrelated. This has led to an innovated read-out processing, wherein linear and non-linear distortions are treated separately, while still using the MLSE structure that may be simplified dramatically.The Non-linear MLSE is based on a two-stage structure that performs linear as well as non-linear processing. The first stage has an adaptive matched filter and a non-linear Volterra canceller for preprocessing the signal to remove its non-linear distortion coefficient. The remainder signal is now only affected by linear distortion, and processed in the usual manner in an MLSE based on a Viterbi detector (VD).
SUMMARY TO THE INVENTION
In consequence, amongst other things, it is an object of the present invention to combine linear and non-linear detection mechanisms into an innovative linear and non-linear receiver structure. Now therefore, according to one of its aspects the invention is characterized according to the characterizing part of claim
1
.
The invention also relates to a device arranged for implementing the above method. Further advantageous aspects of the invention are recited in dependent Claims.
REFERENCES:
patent: 4993047 (1991-02-01), Moffatt et al.
patent: 5111484 (1992-05-01), Karabinis
patent: 5606464 (1997-02-01), Agazzi et al.
patent: 5983254 (1999-11-01), Azadet
patent: 6118832 (2000-09-01), Mayrargue et al.
patent: 6185716 (2001-02-01), Riggle
Agazzi et al., When Can Tentative Decisions be Used to Cancel (Linear or Nonlinear) Intersymbol Interference? (With Application to Magnetic Recording Channels), 1995 IEEE International Conference, vol. 1, pp. 647-652.*
Jean et al. , Nonlinear Equalization for Reduction of Nonlinear Distortion in High-Density Recording Channels, Feb. 1995, IEEE International Conference on, vol. 1, pp. 503-507.
Agarossi Luigi
Bellini Sandro
Bregoli Fabrizio
Migliorati Pierangelo
Belk Michael E.
Koninklijke Philips Electronics , N.V.
Liu Shuwang
LandOfFree
Method and device for nonlinear maximum likelihood sequence... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and device for nonlinear maximum likelihood sequence..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for nonlinear maximum likelihood sequence... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3061474