TITLE:         Multi-track (d,k) codes
AUTHORS:       M. W. Marcellin and E. K. Orcutt
CONFERENCE:    IEEE Information Theory Workshop, Fuji Institute 
               of Education and Training, Japan, June 1993
ABSTRACT:
Multi-track (d,k) codes were recently introduced as a method to increase 
storage densities in magnetic and optical recording systems.  These codes 
are a generalization of the usual run-length-limited (d,k) codes and provide 
for increased storage density by relaxing the k-constraint and encoding 
multiple tracks in parallel.  
 
The talk will begin with a description of multi-track (d,k) constraints and 
methods for computing capacities.  A new class of multi-track block-codes 
will then be presented.  These codes can be implemented via an enumeration 
scheme based on the trellis description of the (d,k) constraints.  This 
implementation results in computational (and memory) requirements which
increase only linearly with block-length.  Finally, a modified version of 
the multi-track (d,k) constraints will be presented.  Codes that result from 
this modification are more robust to synchronization problems caused by the 
loss of one or more tracks during read-back.