Patent · US Expired

Encoding and detection of balanced codes

US6016330A · kind A · utility

15Cited by
10References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 18, 1996
Grant dateJan 18, 2000
Priority date
Expiry dateOct 18, 2016

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L1/0054
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

The present invention is an apparatus and method for detecting a codeword from a data stream comprising a series of sequences of samples representing intensities of an analog signal. The data stream may be output from, for example, a holographic storage device. The data stream is encoded using a code which may be represented by a trellis. One embodiment of the present invention uses a block encoded balanced code, one embodiment uses a finite state encoded balanced code and another embodiment uses a finite-state encoded DC free code. Each code defines a set of codewords which meet the constraints of the code. The codewords are detected from a sequence of samples by selecting the codeword having the greatest correlation with the sequence of samples. In a preferred embodiment, the correlation detection is implemented using the Viterbi process to iteratively determine correlations and codewords for each state at each level of the trellis based on the correlations at the preceding level of the trellis.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.