Rates of constant-composition codes that mitigate intercell interference

For certain families of substrings F, we provide a closed formula for the maximum size of a q-ary F-avoiding code with a given composition. In addition, we provide numerical procedures to determine the asymptotic information rate for F-avoiding codes with certain composition ratios. Using our procedures, we recover known results and compute the information rates for certain classes of F-avoiding constant-composition codes for 2 ≤ q ≤ 8. For these values of q, we find composition ratios such that the rates of F-avoiding codes with constant composition achieve the capacity of the F-avoiding channel.