Abstract: Applications for physical layer security are disclosed. One such application is a system comprising a medical sensor device and a wireless communication module. The medical sensor device is operable to generate data representative of a condition of a patient. The wireless communication module is operable to transmit, on a wireless communication channel, the generated data representative of the condition of the patient. The system also includes a physical layer security module residing at a physical layer of the wireless communication module. The physical layer security module is operable to provide a secrecy zone around the physical layer security module by transforming the generated data such that transmission of the generated data is secured from interception by an eavesdropper on the wireless communication channel.

Abstract: Systems, devices, and methods of physical layer security are disclosed. One such device includes a physical layer security module and a physical layer processing module. The physical layer security module is operable to transform user data in accordance with security characteristics. The physical layer processing module is operable to process the transformed data into a format suitable for the communication channel and further operable to transmit the processed data onto the communication channel. The security characteristics of the physical layer security module are such that decoding the intercepted user data by the eavesdropper results in a bit error rate of about one-half.

Abstract: Disclosed is a method and apparatus for coding in a communication system. The coding method includes generating an information codeword vector from an information vector, generating a first vector in the information vector from an information part of a parity check matrix, generating a first parity codeword vector by performing an exclusive OR operation of the first vector and a second vector corresponding to a cyclically shifted version of the first vector, and generating a second parity codeword vector by performing an exclusive OR operation of the first vector, the first parity codeword vector, and a third vector. The third vector is a cyclically shifted version of a vector resulting from the exclusive OR operation of the first vector, the first parity codeword vector, and a fed-back third vector.

Abstract: In a communication system, a signal transmission apparatus includes an encoder for encoding an information vector into a low density parity check (LDPC) codeword with an LDPC coding scheme, and a puncturer for puncturing the LDPC codeword according to a coding rate using a puncturing scheme. A signal reception apparatus includes a ‘0’ inserter for inserting ‘0’ symbols in a received signal according to a coding rate used in a signal transmission apparatus, and a decoder for decoding the ‘0’ symbol-inserted signal with a decoding scheme corresponding to a low density parity check (LDPC) coding scheme used in the signal transmission apparatus, thereby detecting an information vector.

Abstract: Disclosed is a method and apparatus for coding in a communication system. The coding method includes generating an information codeword vector from an information vector, generating a first vector in the information vector from an information part of a parity check matrix, generating a first parity codeword vector by performing an exclusive OR operation of the first vector and a second vector corresponding to a cyclically shifted version of the first vector, and generating a second parity codeword vector by performing an exclusive OR operation of the first vector, the first parity codeword vector, and a third vector. The third vector is a cyclically shifted version of a vector resulting from the exclusive OR operation of the first vector, the first parity codeword vector, and a fed-back third vector.

Abstract: A method for puncturing a low density parity check (LDPC) code that is decoded through a parity check matrix expressed by a factor graph including check nodes and bit nodes connected to the check nodes through edges. The method includes classifying the bit nodes mapped to a parity part of a codeword into hierarchical groups according to their decoding facilities when the bit nodes are punctured, determining puncturing order of the groups, and sequentially performing puncturing on the bit nodes from a bit node belonging to a corresponding group according to the puncturing order of the groups to acquire a codeword with a desired coding rate.

Abstract: A system and method for enabling efficient error correction and encryption using wavelet transforms over finite fields. The system and method utilizes the combination of a channel encoder and channel decoder to correct errors to source data after transmission over a physical channel or storage in a storage medium. The channel encoder mathematically generates a set of wavelet coefficients by performing a combination of filtering and/or processing of a received message vector. The wavelet coefficients are then utilized by the channel encoder to cause its filters to transform message data into transmission data. The channel decoder receives the transmitted source data in the form of a code word/channel error combination and performs filtering to render a syndrome, representative of the channel error. Analysis of the syndrome is performed to determine the actual error, which is utilized to derive the actual source data.

Abstract: A computer program product, apparatus, and method for correcting errors introduced into a set of data bits during transmission of the set of data bits over a channel includes determining a confidence measure for each data bit based only on the values of one or more of the data bits, each confidence measure representing the probability that the value of the corresponding data bit is correct; and changing the value of a given data bit when the confidence measure for the given data bit indicates that the value of the given data bit is not correct, thereby producing a corrected data bit.

Abstract: A system is provided for decoding product codes. The system includes a processor configured with logic to generate syndromes for a first codeword test pattern and generate syndromes for subsequent codeword test patterns using a recursive function of the syndromes generated for a codeword test pattern previously generated.

Abstract: A system and method are disclosed for reading a multilevel signal from an optical disc. The method includes reading a raw analog data signal from a disc using an optical detector and adjusting the amplitude of the raw analog data signal. A timing signal is recovered from the amplitude adjusted analog data signal and correction is made for amplitude modulation of the raw analog data signal by processing the raw analog data signal and the timing signal.

Abstract: A system and method for reading data to and writing data from multi-level (M-ary) partial response channels uses a trellis coder to encode an input bit stream sequence into a stream of multi-level data symbols. The data symbols are written to the partial response channel using any of a number of techniques. Preferably, the trellis coder anticipates the modulation transfer function of the partial response channel in encoding the data. Because the partial response channel has its own transfer function, the relationship between the data read from the channel and the actual input data bits is a function not only of the data encoder but also of the partial response channel. Therefore, a decoder specification used to implement the decoder takes into account the effect of the trellis encoder as well as the effect of the partial response channel.

Abstract: A system and method are disclosed for reading a multilevel signal from an optical disc. The method includes reading a raw analog data signal from a disc using an optical detector and adjusting the amplitude of the raw analog data signal. A timing signal is recovered from the amplitude adjusted analog data signal and correction is made for amplitude modulation of the raw analog data signal by processing the raw analog data signal and the timing signal.

Abstract: A system for encoding digital data with an M-ary (d,k) code to provide multi-level coded data where M>2 comprises an M-ary (d,k) encoder for accepting digital input data. The M-ary (d,k) coder encodes the digital input data to produce a plurality of code symbols, where each code symbol is at one of M levels and each pair of non-zero code symbols is separated by at least d but no more than k zeros. A waveform encoder converts the code symbols into waveform signal amplitudes compatible with a multi-level channel. Each waveform signal amplitude is generated by modulo M addition of a current code symbol with a previous waveform signal amplitude. A specific M=10(2,10) code provides high density recording to a multi-level storage medium. The M=10 (2,10) encoder is implemented using a seven-state encoder and a modulo ten waveform encoder.

Abstract: A system for encoding digital data with an M-ary (d,k) code to provide multi-level coded data where M>2 comprises an M-ary (d,k) encoder for accepting digital input data. The M-ary (d,k) coder encodes the digital input data to produce a plurality of code symbols, where each code symbol is at one of M levels and each pair of non-zero code symbols is separated by at least d but no more than k zeros. A waveform encoder converts the code symbols into waveform signal amplitudes compatible with a multi-level channel. Each waveform signal amplitude is generated by modulo M addition of a current code symbol with a previous waveform signal amplitude. A specific M-ary (d,k) code provides high density recording to a multi-level storage medium. The M-ary (d,k) encoder is implemented using a M-state encoder and a modulo M waveform encoder.

Abstract: A system for encoding digital data with an M-ary (d,k) code to provide multi-level coded data where M>2 comprises an M-ary (d,k) encoder for accepting digital input data. The M-ary (d,k) coder encodes the digital input data to produce a plurality of code symbols, where each code symbol is at one of M levels and each pair of non-zero code symbols is separated by at least d but no more than k zeros. A waveform encoder converts the code symbols into waveform signal amplitudes compatible with a multi-level channel. Each waveform signal amplitude is generated by modulo M addition of a current code symbol with a previous waveform signal amplitude. A specific M=8 (1,2) code provides high density recording to a multi-level storage medium. The M=8 (1,2) encoder is implemented using a four-state encoder and a modulo eight waveform encoder.

Abstract: A system for encoding digital data with an M-ary (d,k) code to provide multi-level coded data where M>2 comprises an M-ary (d,k) encoder for accepting digital input data. The M-ary (d,k) coder encodes the digital input data to produce a plurality of code symbols, where each code symbol is at one of M levels and each pair of non-zero code symbols is separated by at least d but no more than k zeros. A waveform encoder converts the code symbols into waveform signal amplitudes compatible with a multi-level channel. Each waveform signal amplitude is generated by modulo M addition of a current code symbol with a previous waveform signal amplitude. A specific M=8(1,3) code provides high density recording to a multi-level storage medium. The M=8(1,3) encoder is implemented using a two-state encoder and a modulo eight waveform encoder.

Abstract: A system for encoding digital data with an M-ary (d,k) code to provide multi-level coded data where M>2 comprises an M-ary (d,k) encoder for accepting digital input data. The M-ary (d,k) coder encodes the digital input data to produce a plurality of code symbols, where each code symbol is at one of M levels and each pair of non-zero code symbols is separated by at least d but no more than k zeros. A waveform encoder converts the code symbols into waveform signal amplitudes compatible with a multi-level channel. Each waveform signal amplitude is generated by modulo M addition of a current code symbol with a previous waveform signal amplitude. A specific M=7 (3,8) code provides high density recording to a multi-level storage medium. The M=7 (3,8) encoder is implemented using a five-state encoder and a modulo seven waveform encoder.

Abstract: A system for encoding digital data with an M-ary (d,k) code to provide multi-level coded data where M>2 comprises an M-ary (d,k) encoder for accepting digital input data. The M-ary (d,k) coder encodes the digital input data to produce a plurality of code symbols, where each code symbol is at one of M levels and each pair of non-zero code symbols is separated by at least d but no more than k zeros. A waveform encoder converts the code symbols into waveform signal amplitudes compatible with a multi-level channel. Each waveform signal amplitude is generated by modulo M addition of a current code symbol with a previous waveform signal amplitude. A specific M=6 (4,11) code provides high density recording to a multi-level storage medium. The M=6 (4,11) encoder is implemented using a six-state encoder and a modulo six waveform encoder.

Abstract: A system for encoding digital data with an M-ary (d,k) code to provide multi-level coded data where M>2 comprises an M-ary (d,k) encoder for accepting digital input data. The M-ary (d,k) coder encodes the digital input data to produce a plurality of code symbols, where each code symbol is at one of M levels and each pair of non-zero code symbols is separated by at least d but no more than k zeros. A waveform encoder converts the code symbols into waveform signal amplitudes compatible with a multi-level channel. Each waveform signal amplitude is generated by modulo M addition of a current code symbol with a previous waveform signal amplitude. A specific M=4 (1,2) code provides high density recording to a multi-level storage medium. The M=4 (1,2) encoder is implemented using a three-state encoder and a modulo four waveform encoder.

Abstract: A system for encoding digital data with an M-ary (d,k) code to provide multi-level coded data where M>comprises an M-ary (d,k) encoder for accepting digital input data. The M-ary (d,k) coder encodes the digital input data to produce a plurality of code symbols, where each code symbol is at one of M levels and each pair of non-zero code symbols is separated by at least d but no more than k zeros. A waveform encoder converts the code symbols into waveform signal amplitudes compatible with a multi-level channel. Each waveform signal amplitude is generated by modulo M addition of a current code symbol with a previous waveform signal amplitude. A specific M=(3,8) code provides high density recording to a multi-level storage medium. The M=6 (3,8) encoder is implemented using a ten-state encoder and a modulo six waveform encoder.