SHANNON CAPACITY OF M-ARY REDUNDANT MULTITRACK RUNLENGTH-LIMITED CODES

We consider multiamplitude, multitrack runlength-limited (d, k) constr ained channels with and without clock redundancy. We calculate the Sha nnon capacities of these channels and present some simple 100% efficie nt codes, To compute capacity a constraint graph equivalent to the usu al runlength-limited constraint graph is used, The introduced graph mo del has the vertex labeling independent of number of tracks to be writ ten on (in parallel), which provides computational savings when the nu mber of tracks is large. We show that increasing the number of tracks written on in parallel provides significant increase of per-track capa city for the more restrictive clocking constraint case, i.e., when k < d, but it does not have much influence on the channel capacity, when k greater than or equal to d.