On the Capacity of Bounded Rank Modulation for Flash Memories

Rank modulation has been recently introduced as a new information representation scheme for flash memories. Given the charge levels of a group of flash cells, sorting is used to induce a permutation, which in turn represents data. Motivated by the lower sorting complexity of smaller cell groups, the authors consider bounded rank modulation, where a sequence of permutations of given sizes are used to represent data. The authors study the capacity of bounded rank modulation under the condition that permutations can overlap for higher capacity.