The Experts below are selected from a list of 36813 Experts worldwide ranked by ideXlab platform
Tetsuya Shimamura - One of the best experts on this subject based on the ideXlab platform.
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Amplitude Banded RLS Approach to Time Variant Channel Equalization
IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences, 2001Co-Authors: Tetsuya Shimamura, Colin CowanAbstract:SUMMARY This paper proposes a non-linear adaptive algorithm, the amplitude banded RLS (ABRLS) algorithm, as an adaptation procedure for time variant channel equalizers. In the ABRLS algorithm, a coefficient matrix is updated based on the amplitude level of the Received Sequence. To enhance the capability of tracking for the ABRLS algorithm, a parallel adaptation scheme is utilized which involves the structures of decision feedback equalizer (DFE). Computer simulations demonstrate that the novel ABRLS based equalizer provides a significant improvement relative to the conventional RLS DFE on a rapidly time variant communication channel.
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EUSIPCO - ABRLS algorithm for time variant channel equalisation
1998Co-Authors: Tetsuya Shimamura, Colin CowanAbstract:This paper proposes a non-linear adaptive algorithm, the ABRLS algorithm, as an adaptation procedure for time variant channel equalisers. In the ABRLS algorithm, a coefficient matrix is updated based on the amplitude level of the Received Sequence. To enhance the tracking capability of the ABRLS algorithm, a parallel adaptation scheme is deployed which involves the structures of decision feedback equaliser(DFE). Computer simulations demonstrate that the novel ABRLS DFE provides a significant improvement related to the conventional RLS DFE on rapidly time variant communication channels.
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ISCAS (4) - Nonuniform amplitude division for ABLMS equalisation
ISCAS 2001. The 2001 IEEE International Symposium on Circuits and Systems (Cat. No.01CH37196), 1Co-Authors: Tetsuya ShimamuraAbstract:This paper studies the operation to divide the amplitude of the Received Sequence, which is used to select the coefficients to be updated for each iteration in the amplitude banded LMS (ABLMS) equaliser. A novel nonuniform division method is developed. Computer simulations demonstrate that the ABLMS equaliser involving the novel division method provides a performance improvement relative to the original ABLRS equaliser as well as the LMS equaliser, while the RLS equaliser provides no advantages over the LMS equalised in the case of a second order Markov communication channel model.
Tadao Kasami - One of the best experts on this subject based on the ideXlab platform.
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A test pattern selection method for a joint bounded-distance and encoding-based decoding algorithm of binary codes [Transactions Letters]
IEEE Transactions on Communications, 2010Co-Authors: Hitoshi Tokushige, Marc P. C. Fossorier, Tadao KasamiAbstract:For binary linear block codes, this letter deals with a class of decoding algorithms which utilize bounded-distance and encoding-based decodings with input Sequences that are calculated from a Received Sequence and given test patterns. We propose a new method for selecting the test patterns by simulation. The effectiveness of the decoding algorithm whose test patterns are selected by the proposed method is also shown by simulation.
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Selection of Test Patterns in an Iterative Erasure and Error Decoding Algorithm for Non-binary Block Codes
IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences, 2006Co-Authors: Hitoshi Tokushige, Ippei Hisadomi, Tadao KasamiAbstract:This letter considers an iterative decoding algorithm for non-binary linear block codes in which erasure and error decoding is performed for input words given by the sums of a hard-decision Received Sequence and given test patterns. We have proposed a new selection method of test patterns for the iterative decoding algorithm. Simulation results have shown that the decoding algorithm with test patterns by the proposed selection method provides better error performance than a conventional iterative decoding algorithm with the same number of the error and erasure decoding iterations over an additive white Gaussian noise channel using binary phase-shift keying modulation.
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The Map and Related Decoding Algorithms
Trellises and Trellis-Based Decoding Algorithms for Linear Block Codes, 1998Co-Authors: Shu Lin, Tadao Kasami, Toru Fujiwara, Marc P. C. FossorierAbstract:In a coded communication system with equiprobable signaling, MLD minimizes the word error probability and delivers the most likely codeword associated with the corresponding Received Sequence. This decoding has two drawbacks. First, minimization of the word error probability is not equivalent to minimization of the bit error probability. Therefore, MLD becomes suboptimum with respect to the bit error probability. Second, MLD delivers a hard-decision estimate of the Received Sequence, so that information is lost between the input and output of the ML decoder. This information is important in coded schemes where the decoded Sequence is further processed, such as concatenated coding schemes, multi-stage and iterative decoding schemes.
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A Recursive Maximum Likelihood Decoding
Trellises and Trellis-Based Decoding Algorithms for Linear Block Codes, 1998Co-Authors: Shu Lin, Tadao Kasami, Toru Fujiwara, Marc P. C. FossorierAbstract:The Viterbi algorithm is indeed a very simple and efficient method of implementing the maximum likelihood decoding. However, if we take advantage of the structural properties in a trellis section, other efficient trellis-based decoding algorithms can be devised. Recently, an efficient trellis-based recursive maximum likelihood decoding (RMLD) algorithm for linear block codes has been proposed [37]. This algorithm is more efficient than the conventional Viterbi algorithm in both computation and hardware requirements. Most importantly, the implementation of this algorithm does not require the construction of the entire code trellis, only some special one-section trellises of relatively small state and branch complexities are needed for constructing path (or branch) metric tables recursively. At the end, there is only one table which contains only the most likely codeword and its metric for a given Received Sequence r = (r1, r2, …, r N ). This algorithm basically uses the divide and conquer strategy. Furthermore, it allows parallel/pipeline processing of Received Sequences to speed up decoding.
Dang Qun - One of the best experts on this subject based on the ideXlab platform.
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In-Symbol Correlation Spectrum Sensing Method for OFDM Systems in Cognitive Radio
Computer Science, 2011Co-Authors: Dang QunAbstract:Based on characteristic of periodic Sequence,a novel spectrum sensing method that takes the correlation calculation was proposed in OFDM systems.Firstly,divided the Received Sequence into two part,and took average calculation respective to reduce the noise variance in an OFDM symbol,then used the two sub-Sequences to take the correlation calculation,the influence brought by time-vary channel could be reduced.And the expectation and variance of correlation value were analyzed,verifying the new method was of validity.The experiments showed that the new method outperforms the traditional method in time-vary channel,reduces the number of symbols involved in the calculation,and has the low calculation complexity.
Manuel Roveri - One of the best experts on this subject based on the ideXlab platform.
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on line reconstruction of missing data in sensor actuator networks by exploiting temporal and spatial redundancy
International Joint Conference on Neural Network, 2012Co-Authors: Cesare Alippi, Giacomo Boracchi, Manuel RoveriAbstract:Data streams from remote monitoring systems such as wireless sensor networks show immediately that the “you sample you get” statement is not always true. Not rarely, the data stream is interrupted by intermittent communication or sensors faults, resulting in missing data in the Received Sequence. This has a negative impact in many algorithms assuming continuous data stream; as such, the missing data must be suitably reconstructed, in order to guarantee continuous data availability. We suggest a general methodology for reconstructing missing data that exploits both temporal and spatial redundancy characterizing the phenomenon being monitored and the distributed system, a situation proper of many monitoring systems constituted by sensor and actuator networks. Temporal and spatial dependencies are learned through linear and non-linear non-parametric models, also encompassing neural -possibly recurrent- networks, which become the spatial transfer functions connecting the different views of the phenomenon under investigation. Missing data are finally reconstructed by exploiting the forecasting ability provided by such transfer functions. The experimental section shows the effectiveness of the proposed methodology.
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IJCNN - On-line reconstruction of missing data in sensor/actuator networks by exploiting temporal and spatial redundancy
The 2012 International Joint Conference on Neural Networks (IJCNN), 2012Co-Authors: Cesare Alippi, Giacomo Boracchi, Manuel RoveriAbstract:Data streams from remote monitoring systems such as wireless sensor networks show immediately that the “you sample you get” statement is not always true. Not rarely, the data stream is interrupted by intermittent communication or sensors faults, resulting in missing data in the Received Sequence. This has a negative impact in many algorithms assuming continuous data stream; as such, the missing data must be suitably reconstructed, in order to guarantee continuous data availability. We suggest a general methodology for reconstructing missing data that exploits both temporal and spatial redundancy characterizing the phenomenon being monitored and the distributed system, a situation proper of many monitoring systems constituted by sensor and actuator networks. Temporal and spatial dependencies are learned through linear and non-linear non-parametric models, also encompassing neural -possibly recurrent- networks, which become the spatial transfer functions connecting the different views of the phenomenon under investigation. Missing data are finally reconstructed by exploiting the forecasting ability provided by such transfer functions. The experimental section shows the effectiveness of the proposed methodology.
Rudiger Urbanke - One of the best experts on this subject based on the ideXlab platform.
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A New Coding Paradigm for the Primitive Relay Channel.
arXiv: Information Theory, 2018Co-Authors: Marco Mondelli, S. Hamed Hassani, Rudiger UrbankeAbstract:We present a coding paradigm that provides a new achievable rate for the primitive relay channel by combining compress-and-forward and decode-and-forward with a chaining construction. In the primitive relay channel model, the source broadcasts a message to the relay and to the destination; and the relay facilitates this communication by sending an additional message to the destination through a separate channel. Two well-known coding approaches for this setting are decode-and-forward and compress-and-forward: in the former, the relay decodes the message and sends some of the information to the destination; in the latter, the relay does not attempt to decode, but it sends a compressed description of the Received Sequence to the destination via Wyner-Ziv coding. In our scheme, we transmit over pairs of blocks and we use compress-and-forward for the first block and decode-and-forward for the second. In particular, in the first block, the relay does not attempt to decode and it sends only a part of the compressed description of the Received Sequence; in the second block, the relay decodes the message and sends this information plus the remaining part of the compressed Sequence relative to the first block. As a result, we strictly outperform both compress-and-forward and decode-and-forward. Furthermore, this paradigm can be implemented with a low-complexity polar coding scheme that has the typical attractive features of polar codes, i.e., quasi-linear encoding/decoding complexity and super-polynomial decay of the error probability. Throughout the paper we consider as a running example the special case of the erasure relay channel and we compare the rates achievable by our proposed scheme with the existing upper and lower bounds.
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ISIT - A New Coding Paradigm for the Primitive Relay Channel
2018 IEEE International Symposium on Information Theory (ISIT), 2018Co-Authors: Marco Mondelli, S. Hamed Hassani, Rudiger UrbankeAbstract:We present a coding paradigm that provides a new achievable rate for the primitive relay channel by combining compress-and-forward and decode-and-forward with a chaining construction. In the primitive relay channel model, the source broadcasts a message to the relay and to the destination; and the relay facilitates this communication by sending an additional message to the destination through a separate channel. Two well-known coding approaches for this setting are decode-and-forward and compress-and-forward: in the former, the relay decodes the message and sends some of the information to the destination; in the latter, the relay does not attempt to decode, but it sends a compressed description of the Received Sequence to the destination via Wyner-Ziv coding. In our scheme, we transmit over pairs of blocks and we use compress-and-forward for the first block and decode-and-forward for the second. In particular, in the first block, the relay does not attempt to decode and it sends only a part of the compressed description of the Received Sequence; in the second block, the relay decodes the message and sends this information plus the remaining part of the compressed Sequence relative to the first block. As a result, we strictly outperform both compress-and- forward and decode-and-forward. Furthermore, this paradigm can be implemented with a low-complexity polar coding scheme that has the typical attractive features of polar codes, i.e., quasi-linear encoding/decoding complexity and super-polynomial decay of the error probability. Throughout the paper we consider as a running example the special case of the erasure relay channel and we compare the rates achievable by our proposed scheme with the existing upper and lower bounds.
