English

Construction of Fixed Rate Non-Binary WOM Codes based on Integer Programming

Information Theory 2018-02-14 v1 math.IT

Abstract

In this paper, we propose a construction of non-binary WOM (Write-Once-Memory) codes for WOM storages such as flash memories. The WOM codes discussed in this paper are fixed rate WOM codes where messages in a fixed alphabet of size MM can be sequentially written in the WOM storage at least tt^*-times. In this paper, a WOM storage is modeled by a state transition graph. The proposed construction has the following two features. First, it includes a systematic method to determine the encoding regions in the state transition graph. Second, the proposed construction includes a labeling method for states by using integer programming. Several novel WOM codes for qq level flash memories with 2 cells are constructed by the proposed construction. They achieve the worst numbers of writes tt^* that meet the known upper bound in many cases. In addition, we constructed fixed rate non-binary WOM codes with the capability to reduce ICI (inter cell interference) of flash cells. One of the advantages of the proposed construction is its flexibility. It can be applied to various storage devices, to various dimensions (i.e, number of cells), and various kind of additional constraints.

Keywords

Cite

@article{arxiv.1701.08347,
  title  = {Construction of Fixed Rate Non-Binary WOM Codes based on Integer Programming},
  author = {Yoju Fujino and Tadashi Wadayama},
  journal= {arXiv preprint arXiv:1701.08347},
  year   = {2018}
}