823 research outputs found
On Coding Efficiency for Flash Memories
Recently, flash memories have become a competitive solution for mass storage.
The flash memories have rather different properties compared with the rotary
hard drives. That is, the writing of flash memories is constrained, and flash
memories can endure only limited numbers of erases. Therefore, the design goals
for the flash memory systems are quite different from these for other memory
systems. In this paper, we consider the problem of coding efficiency. We define
the "coding-efficiency" as the amount of information that one flash memory cell
can be used to record per cost. Because each flash memory cell can endure a
roughly fixed number of erases, the cost of data recording can be well-defined.
We define "payload" as the amount of information that one flash memory cell can
represent at a particular moment. By using information-theoretic arguments, we
prove a coding theorem for achievable coding rates. We prove an upper and lower
bound for coding efficiency. We show in this paper that there exists a
fundamental trade-off between "payload" and "coding efficiency". The results in
this paper may provide useful insights on the design of future flash memory
systems.Comment: accepted for publication in the Proceeding of the 35th IEEE Sarnoff
Symposium, Newark, New Jersey, May 21-22, 201
Write-Once-Memory Codes by Source Polarization
We propose a new Write-Once-Memory (WOM) coding scheme based on source
polarization. By applying a source polarization transformation on the
to-be-determined codeword, the proposed WOM coding scheme encodes information
into the bits in the high-entropy set. We prove in this paper that the proposed
WOM codes are capacity-achieving. WOM codes have found many applications in
modern data storage systems, such as flash memories.Comment: 5 pages, Proceedings of the International Conference on Computing,
Networking and Communications (ICNC 2015), Anaheim, California, USA, February
16-19, 201
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