Japanese Patent JPH0584099

B2

A method termed Even Mark Modulation (EMM) is disclosed for coding input strings for input-restricted (1 + D) or (1 + D)<2> partial response channels that require at least one pair of consecutive signals of one state in order to record or transmit data to a receiving device. EMM provides improved coding gains and is especially suitable for optical recording. An input string is encoded into a binary code string in which all one-state signals (e.g., "1's") are in the form of runs of at least one contiguous pair; however, signals of an opposite state (e.g., "0's") may be of any length or duration. The EMM signals are detected with a maximum likelihood detector using an algorithm based on a three-state trellis structure for (1 + D) channels and a five-state trellis structure for (1 + D)<2> channels adapted to the particular partial response channel. In a preferred embodiment, the coding rate is 2/3 and the coding gain is at least 3 dB un-normalised and at least 2.2 dB when normalised. A finite-state encoder and sliding block decoder are disclosed, together with logic equations for encoder and decoder circuits.

JP3462000	ADAPTIVE EQUALIZER
JPS55109061	DEVICE FOR TRANSMITTING TELEGRAPH CODE
WO/1999/012315	CIRCUIT AND METHOD FOR MINIMISING BIT ERRORS

RAZUMIKU KARABEDO
HOORU HAWAADO SHIIIGERU

JP31867488A

November 30, 1993

December 19, 1988

Click for automatic bibliography generation  

INTAANASHONARU BIJINESU MASHIINZU CORP

H04L25/08; G11B20/10; H03M5/14; H03M13/23; H04L25/49; H04L25/497; (IPC1-7): H04L25/497; H04L25/08

Next Patent: JPH0584100