Bounds and Code Constructions for Partially Defect Memory Cells
Document type:
Konferenzbeitrag
Author(s):
Haider Al Kim, Sven Puchinger, and Antonia Wachter-Zeh
Abstract:
This paper considers coding for so-called partially
stuck memory cells. Such memory cells can only store partial
information as some of their levels cannot be used due to, e.g.,
wear out. First, we present a new code construction for masking
such partially stuck cells while additionally correcting errors.
This construction (for cells with q > 2 levels) is achieved by
generalizing an existing masking-only construction in [1] (based
on binary codes) to correct errors as well. Compared to previous
constructions in [2], our new construction achieves larger rates
for many sets of parameters. Second, we derive a sphere-packing
(any number of u partially stuck cells) and a Gilbert-Varshamov
bound (u < q partially stuck cells) for codes that can mask
a certain number of partially stuck cells and correct errors
additionally. A numerical comparison between the new bounds
and our previous construction of PSMCs for the case u < q in [2]
shows that our construction lies above the Gilbert–Varshamovlike bound for several code parameters.