Apple Inc.
Iterative decoding with early termination criterion that permits errors in redundancy part

Abstract:

An apparatus includes an interface and a decoder. The interface is configured to receive a code word, produced in accordance with an Error Correction Code (ECC) represented by a set of parity check equations. The code word includes a data part and a redundancy part, and contains one or more errors. The decoder is configured to hold a definition of a partial subgroup of the parity check equations that, when satisfied, indicate that the data part is error-free with a likelihood of at least a predefined threshold, to decode the code word by performing an iterative decoding process on the parity check equations, so as to correct the errors, and during the iterative decoding process, to estimate whether the data part is error-free based only on the partial subgroup of the parity check equations, and if the data part is estimated to be error-free, terminate the iterative decoding process.