Abstract: A sequential decoding method and a decoding apparatus are provided. According to the method, an open stack is adopted for storing a plurality of paths. When the codeword generated by an internal decoder in the decoding apparatus is incorrect, a codeword is generated again by using the paths stored in the open stack. Accordingly, the complexity of decoding is reduced.

Abstract: A decoding method and system for real-time wireless channel estimation, which decodes a received signal with a noise. The received signal is coded by a concatenation code. At first, the received signal is performed a certain amount of decoding by a Max-Log-MAP decoding procedure. Next, an estimated amplitude of the received signal and an estimated variance of a noise are computed. Then, the received signal is adjusted in accordance with the estimated amplitude and the estimated variance to thereby produce an adjusted received signal. Finally, the adjusted received signal is decoded by a Log-Map decoding procedure.

Abstract: A method for near maximum-likelihood sequential decoding is provided. According to the method, paths unlikely to become the maximum-likely path are deleted during decoding through a level threshold to reduce decoding complexity. Besides, the method performs maximum-likelihood decoding through sequential decoding by adopting a metric, so that a received signal does not have to go through a hard decision procedure.

Abstract: A method for BTFD decoding of signals having at least a message block of k-bit from a length candidate set S={s1, s2, . . . si}, wherein the k message bits are encoded by a CRC encoder and processed by an (n, l, m) convolutional encoder to generate encoded data that includes decoding a received frame to form a decoded sequence that includes an si-bit message and an error correcting code, calculating a ?(si) value, comparing ?(si) with a threshold value, repeating the decoding and calculating steps if ?(si) is greater than the threshold, and updating the threshold to be ?(si) if ?(si) is less than or equal to the threshold.

Abstract: A method and apparatus having a modified Reed-Solomon decoder is used for finding a specific code group used by a base station and the frame timing synchronization with the base station. The modified Reed-Solomon decoder uses a standard Reed-Solomon decoder and some reliability measurements computed from the received code word symbols. If the reliability of a received symbol is too low, this symbol is considered as erasure. By selecting code word symbols with higher reliabilities and erasing code word symbols with lower reliabilities, the symbol error probability is reduced and the performance is improved. Several modified Reed-Solomon decoders and a few decoding strategies are introduced in order to decode the received code word sequences with a power- and memory-effective method.

Abstract: A method for mitigating interference is provided. First, a received signal having a training sequence is received from a transmitter. Then, a Signal-to-Interference-plus-Noise Ratio (SINR) of the training sequence in the received signal is calculated, and whether a co-channel interference signal exists in the received signal is determined according to the SINR. The signal power corresponding to each time index in the received signal is calculated to detect a beginning time point and an ending time point of the co-channel interference signal. Finally, when the co-channel interference signal in the received signal is detected, the time when an interference cancellation filter is turned on is determined by the beginning time point and the ending time point.

Abstract: A decoder suitable for use in a digital communications system utilizing an RS(n?, k?) code modified from an RS(n, k) code receives n?-symbol vectors each including k? message symbols and r?=n??k? parity symbols and decodes the n?-symbol vectors to correct errors therein, wherein n, k, n?, and k? are integers, and k?<n?<n, k?<k<n, and wherein the decoder stores therein one erasure locator polynomial ?0(x). The decoder includes a syndrome calculator for receiving the n?-symbol vectors and for calculating syndromes of each n?-symbol vector, wherein the i-th syndrome Si of one n?-symbol vector R?, (rn??1, rn??2, . . . , r0), is Si=Rs(?i+1) for i=0, 1, . . . , n?k?1, wherein Rs(x)=rn??1xn??1+rn??2xn??2+ . . . +r0, and means for finding the locations and values of the errors in each n?-symbol vector using the syndromes thereof and the one erasure locator polynomial ?0(x).

Abstract: A communications system including a base station and a mobile unit wherein a size of information bits is negotiated between the base station and the mobile unit, an encoder encoding the information bits according to Reed-Muller codes, and a permuter permuting the encoded information bits. The information bits are transmitted between the base station and the mobile unit with the negotiated size. The communications system according to the present invention further comprises a depermuter depermuting the transmitted information bits, a transformer transforming the depermuted information bits with a reduced order determined according to the negotiated size, and a maximum likelihood (ML) decoder decoding the transmitted information bits.

Abstract: A method and apparatus having a modified Reed-Solomon decoder is used for finding a specific code group used by a base station and the frame timing synchronization with the base station. The modified Reed-Solomon decoder uses a standard Reed-Solomon decoder and some reliability measurements computed from the received code word symbols. If the reliability of a received symbol is too low, this symbol is considered as erasure. By selecting code word symbols with higher reliabilities and erasing code word symbols with lower reliabilities, the symbol error probability is reduced and the performance is improved. Several modified Reed-Solomon decoders and a few decoding strategies are introduced in order to decode the received code word sequences with a power- and memory-effective method.

Abstract: A sequential decoding method and a decoding apparatus are provided. According to the method, an open stack is adopted for storing a plurality of paths. When the codeword generated by an internal decoder in the decoding apparatus is incorrect, a codeword is generated again by using the paths stored in the open stack. Accordingly, the complexity of decoding is reduced.

Abstract: A decoding method and system for real-time wireless channel estimation, which decodes a received signal with a noise. The received signal is coded by a concatenation code. At first, the received signal is performed a certain amount of decoding by a Max-Log-MAP decoding procedure. Next, an estimated amplitude of the received signal and an estimated variance of a noise are computed. Then, the received signal is adjusted in accordance with the estimated amplitude and the estimated variance to thereby produce an adjusted received signal. Finally, the adjusted received signal is decoded by a Log-Map decoding procedure.

Abstract: A method for near maximum-likelihood sequential decoding is provided. According to the method, paths unlikely to become the maximum-likely path are deleted during decoding through a level threshold to reduce decoding complexity. Besides, the method performs maximum-likelihood decoding through sequential decoding by adopting a metric, so that a received signal does not have to go through a hard decision procedure.

Abstract: In a method for a variable-length communications system including encoding a message and decoding a data bit stream, the message includes a plurality of message blocks. A message block of the message is encoded by generating a parity check bit stream, flipping the parity check bit stream, appending the flipped parity check bit stream and a number of 0's to the end of the message block, and convolutionally encoding the resultant bit stream. When a data bit stream is received, a guessed message block and a guessed flipped parity check bit stream are extracted based on a guessed message block length. A parity check bit stream is generated for the guessed message block and then flipped. If the flipped parity check bit stream is the same as the guessed flipped parity check bit stream, the message block has been identified. Otherwise, the guessed message block length is increased by 1 and the above step is repeated.

Abstract: A method for BTFD decoding of signals having at least a message block of k-bit from a length candidate set S={s1, s2, . . . si}, wherein the k message bits are encoded by a CRC encoder and processed by an (n, l, m) convolutional encoder to generate encoded data that includes decoding a received frame to form a decoded sequence that includes an si-bit message and an error correcting code, calculating a ?(si) value, comparing ?(si) with a threshold value, repeating the decoding and calculating steps if ?(si) is greater than the threshold, and updating the threshold to be ?(si) if ?(si) is less than or equal to the threshold.

Abstract: A decoder suitable for use in a digital communications system utilizing an RS(n?, k?) code modified from an RS(n, k) code receives n?-symbol vectors each including k? message symbols and r?=n?-k? parity symbols and decodes the n?-symbol vectors to correct errors therein, wherein n, k, n?, and k? are integers, and k?<n?<n, k?<k<n, and wherein the decoder stores therein one erasure locator polynomial ?0(x). The decoder includes a syndrome calculator for receiving the n?-symbol vectors and for calculating syndromes of each n?-symbol vector, wherein the i-th syndrome Si of one n?-symbol vector R?, (rn??1, rn??2, . . . , r0), is Si=Rs(?i+1) for i=0, 1, . . . , n?k?1, wherein Rs(x)=rn??1xn??1+rn??2xn??2+ . . . +r0, and means for finding the locations and values of the errors in each n?-symbol vector using the syndromes thereof and the one erasure locator polynomial ?0(x).

Abstract: In a method for a variable-length communications system including encoding a message and decoding a data bit stream, the message includes a plurality of message blocks. A message block of the message is encoded by generating a parity check bit stream, flipping the parity check bit stream, appending the flipped parity check bit stream and a number of 0's to the end of the message block, and convolutionally encoding the resultant bit stream. When a data bit stream is received, a guessed message block and a guessed flipped parity check bit stream are extracted based on a guessed message block length. A parity check bit stream is generated for the guessed message block and then flipped. If the flipped parity check bit stream is the same as the guessed flipped parity check bit stream, the message block has been identified. Otherwise, the guessed message block length is increased by 1 and the above step is repeated.

Abstract: A communications system including a base station and a mobile unit wherein a size of information bits is negotiated between the base station and the mobile unit, an encoder encoding the information bits according to Reed-Muller codes, and a permuter permuting the encoded information bits. The information bits are transmitted between the base station and the mobile unit with the negotiated size. The communications system according to the present invention further comprises a depermuter depermuting the transmitted information bits, a transformer transforming the depermuted information bits with a reduced order determined according to the negotiated size, and a maximum likelihood (ML) decoder decoding the transmitted information bits.

Abstract: A method and apparatus having a modified Reed-Solomon decoder is used for finding a specific code group used by a base station and the frame timing synchronization with the base station. The modified Reed-Solomon decoder uses a standard Reed-Solomon decoder and some reliability measurements computed from the received code word symbols. If the reliability of a received symbol is too low, this symbol is considered as erasure. By selecting code word symbols with higher reliabilities and erasing code word symbols with lower reliabilities, the symbol error probability is reduced and the performance is improved. Several modified Reed-Solomon decoders and a few decoding strategies are introduced in order to decode the received code word sequences with a power- and memory-effective method.