Patent ID: 8930803
Filing Date: 2015-01-06
Classification: G11C

Abstract:
1. A method for detecting codewords in solid-state storage devices, the method comprising the steps of: obtaining, by a processor of the computer system, respective read signals by reading memory cells that stores a group of N-symbol codewords, wherein each of said read signals comprises N signal components corresponding to respective symbols of said codeword; producing, by the processor, an ordered read signal by ordering said components of each of said read signals according to a signal level; producing, by the processor, an average read signal by averaging corresponding components of said ordered read signals; determining, by the processor, a reference signal level that corresponds to each of q levels of said memory cells in relation to said average read signal with predefined probabilities of each symbol value occurring at each symbol position in said codeword, wherein said symbols of said codeword are ordered according to said symbol value; and detecting, by the processor, said codeword corresponding to each of said read signal in relation to said reference signal levels; wherein each of said codewords is a permutation of an N-symbol vector in a predefined set of said N-symbol vectors; wherein each of said symbols of each said codeword has one of q symbol values; and wherein said symbols are stored in respective q-level cells of solid state memory, where N≧q>2.