Method and apparatus for three dimensional sequence estimation in partially constrained binary channels

• Main Authors: MOON; JAEKYUN, BRICKNER; BARRETT J
• Format: Patent
• Language: English
• Published: 21.09.1999
• Edition: 6
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS

An information handling system, such as a magnetic disk drive, includes a data channel which has a method and apparatus for detecting binary symbols from a received signal subject to intersymbol interference and additive white Gaussian noise using a three dimensional observation space with orthogonal coordinate axes. Each of three consecutive synchronous observation samples of the received signal corresponding unambiguously to an axis in the observation space. A decision feedback equalizer removes intersymbol interference terms associated with prior detector outputs. A plurality of linear classifiers are used to partition the observation space. The second and/or third sample of the equivalent channel response is constrained relative to the first for the purpose of simplifying the linear classifiers. Boolean logic functions to decide into which decision region of the observation space a sample maps into. Incorporation of modulation coding constraints reduce the probability of error by increasing the Euclidean distance between symbols in the observation space. Symbol estimates are produced synchronously with a delay of two with respect to the current observation sample.