Correcting errors in miscorrected codewords using list decoding

#The subject matter of this application is related to U.S. patent application Ser. No. 12/675,981 filed on Mar. 2, 2010 and U.S. patent application Ser. No. 12/677,322 filed Mar. 10, 2010, the teachings of all of which are incorporated herein by reference in their entirety.

#Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. The same applies to the term “implementation.”

#Embodiments of the invention will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings.

#FIG. 1 shows a simplified block diagram of a receiving path of a communications system according to one embodiment of the disclosure; and

#FIG. 2 shows a simplified block diagram of a virtual storage system according to one embodiment of the disclosure.

#Referring to FIG. 1, receiving path 100 may be implemented in any communications system suitable for communicating an input data stream over a communications channel (not shown), such as a wireless communications system, a hard-disk drive (HDD) system, or an optical-disk drive system. For example, when implemented in a wireless communications system, receiving path 100 is a receiver, and the communications channel is a wireless transmission medium. When implemented in a hard-disk drive system, the receive path includes the read channel, and the communications channel includes a hard-disk platter.

#In general, receiving path 100 receives, or retrieves in the case of an HDD or optical-disk drive system, an encoded codeword from the communications channel. The encoded codeword is a version of an original input data word that is encoded in a transmitting path (not shown) of the communications system using a cyclic-redundancy-check (CRC) encoding scheme, a low-density parity-check (LDPC) encoding scheme, and a run-length limited (RLL) encoding scheme (in the case of an HDD or optical-disk drive system). Receiving path 100 processes the encoded codeword to recover the original input data word that was encoded in the transmitting path.

#In particular, the encoded codeword is processed by receiving path 100 using upstream processing 102, which may include processing such as amplification, analog-to-digital conversion, finite-impulse-response (FIR) filtering, equalization, and possibly other processing suitable for preparing encoded codewords for decoding. Samples yn of the encoded codeword are provided to channel detector 104 in an order, herein referred to as the “user-data order,” that corresponds to the order in which the original input data word is received from the user in the transmitting path.