Abstract
M.Ing. (Electrical and Electronic Engineering)
During the past decade the optical disc has become increasingly popular. Write-once
optical recording systems will mainly be used in data storage systems in which archival
aspects or mass storage requirements prevail. In write-once optical data storage one is
faced with an asymmetry between marks and non-marks due to a practical lower limit
of the mark size. In some optical fibre communications there is also an asymmetry
present in injection lasers and it may be feasible to use asymmetrical codes.
In this study information theoretical methods are used to find values of channel
capacity for sequences complying with binary asymmetrical runlength constraints.
Different coding methods are used to construct encoders and decoders for generating
and decoding these sequences with high values of efficiency. The power spectra of
maxentropic binary asymmetrical runlength limited sequences complying with different
runlength constraints are also investigated.