Abstract:
PURPOSE: A circuit and method for encoding, decoding, and multistage-decoding a concatenated BCH code, an error correcting circuit of a flash memory device using the same, and the flash memory device are provided to improve error correction performance by repetitively decoding an inner code and an outer code until an error is completely corrected. CONSTITUTION: A first stage code unit outputs a first output BCH code or a parity bit by receiving a part or the entire of data inputted to a flash memory core and performing a BCH encoding operation. An interleaving unit receives and interleaves the part or the entire of the data inputted to the flash memory core and outputs the interleaved data. A second stage code unit performs the BCH encoding operation of the BCH code or the data and outputs a second output BCH code or the parity bit.
Abstract:
PURPOSE: Secure communication using non-systematic error control codes is provided to encode a message by a non systematic error control code, thereby generating an encoded message not to show the original shape of the message. CONSTITUTION: A transmitter(110T) includes an encoder which applies at least one non systematic error control code during message transmission. A receiver(110R) comprises a mutual decoder. The signal-to-noise ratio in a main channel(120) is lower than the signal-to-noise ratio in a concealed microphone channel(150). A concealed microphone(140) taps a transmitter device in the concealed microphone channel. An encoded message is transmitted to a receiver in the main channel.
Abstract:
PURPOSE: A decoding method and an apparatus for layered belief propagation and a medium thereof are provided to reduce the number of times being decoded without increasing decoding complexity by determining the number of a variable intercept and establishing an optimal decoding group based on the distribution of the number of a variable intercept. CONSTITUTION: Each number of a variable intercept and a check intercept are calculated from the parity check matrix H of a irregular LDPC(Low Density Parity Check) code(S310). The variable intercept with a high number has a top priority. Variable intercepts are grouped so that the sum of the number of variable intercepts included within the same group becomes similar and one or more groups are formed(S340). Top priority is given to the group including higher number of a variable intercept among groups and the decoding of belief propagation is performed(S360). Whether the group arrives a maximum iteration number or a parity check is satisfied or not is determined(S370).
Abstract:
PURPOSE: A puncturing method, a puncturing device thereof, and a decoding method in a puncturing process are provided to increase an error detection performance by connecting a CRC code to control information to be transmitted. CONSTITUTION: A generator(210) generates cordwords which is convoluted by connecting a CRC code to control information with k bits. A first calculation unit(220) looks for a minimum free distance and a hamming weight of generated codewords. A second calculator(230) calculates the number of the punctured bits. A code unit(240) obtains the combination and progression of the codewords. A puncturing unit(250) punctures the position of the minimum element among the elements of the progression. An exclusion unit(260) excludes an adjacent position from a puncturing candidate not to puncture the adjacent position.