A new perspective family of universal variable length prefix codes with a set of delimiters is introduced. The main seed of these codes is the binary representation of natural numbers in the two-base numeration system...
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ISBN:
(纸本)9781479985050
A new perspective family of universal variable length prefix codes with a set of delimiters is introduced. The main seed of these codes is the binary representation of natural numbers in the two-base numeration system with the main radix 2 and the auxiliary radix 3. We construct extensions and generalizations of these (2,3)-codes, which we call (Delta, k) codes. We prove that all (Delta, k) -codes are complete. Also for these codes we developed fast and efficient bit-wise and byte-wise encoding and decoding algorithms. Some representatives of (Delta, k) -codes family outperform the known closest to them Fibonacci codes either in text compression efficiency or in computational complexity.
Wireless broadcast advantage (WBA) and wireless cooperative advantage (WCA) are exploited in this paper for finding a cooperative route in a wireless mesh network with minimum energy consumption considering practical ...
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ISBN:
(纸本)9781479974986
Wireless broadcast advantage (WBA) and wireless cooperative advantage (WCA) are exploited in this paper for finding a cooperative route in a wireless mesh network with minimum energy consumption considering practical coding and modulation schemes. In doing so we have assumed a multihop wireless mesh network consisting of nodes capable of adjusting their transmit power. An optimization problem to allocate minimum sum power for a given route subject to a desired end-to-end throughput and outage probability constraints is formulated. WBA and WCA are taken into account separately and together during the resource allocation. Afterwards, optimal and suboptimal route selection is done using a classical Dijkstra's algorithm. Turbo codes with iterative decoding algorithms are implemented with various QAM modulation schemes.
Tail-biting codes are the main control channel coding form for the LTE system. The WAVA algorithm is one of the widely used as the decoding algorithm of tail-biting codes. To fully make use of the information on the a...
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ISBN:
(纸本)9781467381741
Tail-biting codes are the main control channel coding form for the LTE system. The WAVA algorithm is one of the widely used as the decoding algorithm of tail-biting codes. To fully make use of the information on the algebra structure of the tail-biting codes, we combined the WAVA algorithm with the algebraic decoding, and proposed a new joint probabilityalgebraic decoding algorithm. Simulation results show that, compared with the single probability decoding, the new algorithm has better performance on the error correction.
To make full use of the characteristics of LDPC decoding, Stephan ten Brink had proposed a joint iterative demapping and decoding algorithm for LDPC coded BICM systems. Based on Brink proposed algorithm, we propose a ...
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ISBN:
(纸本)9781510821279
To make full use of the characteristics of LDPC decoding, Stephan ten Brink had proposed a joint iterative demapping and decoding algorithm for LDPC coded BICM systems. Based on Brink proposed algorithm, we propose a modified joint iterative scheme to further reduce the computation complex. Different from the algorithm presented by Brink, in the process of iterative demapping and decoding, the proposed method simplifies the update calculation of the LDPC parity check nodes by adopting the UMP-BP. More importantly, to compensate for the performance degradation brought by UMP-BP, LLRs optimization based on certain optimality criterion is employed for the proposed method. Numerical analysis shows that the complexity of the proposed method is less than traditional joint iterative algorithm. Simulation results also show that by LLRs optimization the proposed method achieves noticeable performance improvement compared with the BICM-ID and the joint iterative algorithm.
This paper presents a novel belief propagation (BP) based decoding algorithm for polar codes. The proposed algorithm facilitates belief propagation by utilizing the specific constituent codes that exist in the factor ...
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ISBN:
(纸本)9781479959532
This paper presents a novel belief propagation (BP) based decoding algorithm for polar codes. The proposed algorithm facilitates belief propagation by utilizing the specific constituent codes that exist in the factor graph, which results in an express journey (XJ) for belief information to propagate in each decoding iteration. In addition, this XJ-BP decoder employs a novel round-trip message passing scheduling method for the increased efficiency. The proposed method simplifies min-sum (MS) BP decoder by 40.6%. Along with the round-trip scheduling, the XJ-BP algorithm reduces the computational complexity of MS BP decoding by 90.4%;this enables an energy-efficient hardware implementation of BP decoding in practice.
A unique decoding algorithm for general AG codes, namely multipoint evaluation codes on algebraic curves, is presented. It is a natural generalization of the previous decoding algorithm which was only for one-point AG...
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A unique decoding algorithm for general AG codes, namely multipoint evaluation codes on algebraic curves, is presented. It is a natural generalization of the previous decoding algorithm which was only for one-point AG codes. As such, it retains the same advantages of fast speed, regular structure, and direct message recovery. Upon this generalization, we add a technique from the Guruswami-Sudan list decoding that boosts the decoding speed significantly. Compared with other known decoding algorithms for general AG codes, it has a similar decoding performance and allows streamlined practical implementation by its simple and regular structure.
In this paper we introduce a novel reliable asyn-chronous protocol that allows to establish a VLC link between a LED luminary and an off-the-shelf smartphone. Our protocol and decoding algorithms benefit from the acce...
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ISBN:
(纸本)9781479959532
In this paper we introduce a novel reliable asyn-chronous protocol that allows to establish a VLC link between a LED luminary and an off-the-shelf smartphone. Our protocol and decoding algorithms benefit from the access to advanced camera settings available in the latest generations of mobile devices to outperform previous VLC designs in the state of the art. In particular, in the paper we provide an experimental evaluation using a commercial Nexus 5 device where it is shown how our designed prototype can achieve transmission speeds of up to 700 bps and operating distances of up to 3 meters. The previous performance figures have the potential to spark a wide set of novel applications.
Low-Density Parity-Check (LDPC) decoders typically implement a single decoding algorithm or update rule, which narrows down the design space of the decoder and maintains its overall simplicity. However, gear-shift tec...
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ISBN:
(纸本)9781467369985
Low-Density Parity-Check (LDPC) decoders typically implement a single decoding algorithm or update rule, which narrows down the design space of the decoder and maintains its overall simplicity. However, gear-shift techniques combine multiple decoding algorithms, update rules and quantization of the log-likelihood ratios (LLRs), allowing wider design space explorations as more parameters can be fine-tuned to a particular need. Gear-shift LDPC decoders have been shown to improve both the decoding throughput and the energy efficiency per bit decoded, while achieving similar capacity compared to traditional approaches that only use one algorithm. In this paper, we incorporate gear-shift techniques based on the Min-Sum algorithm (MSA) and Self-Corrected Min-Sum algorithm(SCMSA) using variable quantization steps. The proposed design allows bit error rate (BER) performances close to the more powerful SCMSA running only a selected number of iterations using the most powerful update rule.
The 0-1 multidimensional knapsack problem (MKP) arises in many fields of optimization and is NP-hard. Several exact as well as heuristic methods exist. Recently, an artificial fish swarm algorithm has been developed i...
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The 0-1 multidimensional knapsack problem (MKP) arises in many fields of optimization and is NP-hard. Several exact as well as heuristic methods exist. Recently, an artificial fish swarm algorithm has been developed in continuous global optimization. The algorithm uses a population of points in space to represent the position of fish in the school. In this paper, a binary version of the artificial fish swarm algorithm is proposed for solving the 0-1 MKP. In the proposed method, a point is represented by a binary string of 0/1 bits. Each bit of a trial point is generated by copying the corresponding bit from the current point or from some other specified point, with equal probability. Occasionally, some randomly chosen bits of a selected point are changed from 0 to 1, or 1 to 0, with an user defined probability. The infeasible solutions are made feasible by a decoding algorithm. A simple heuristic add item is implemented to each feasible point aiming to improve the quality of that solution. A periodic reinitialization of the population greatly improves the quality of the solutions obtained by the algorithm. The proposed method is tested on a set of benchmark instances and a comparison with other methods available in literature is shown. The comparison shows that the proposed method gives a competitive performance when solving this kind of problems. (C 2013 Elsevier B.V. All rights reserved.
In this paper, we present a decode-and-forward network coded (DFNC) scheme over GF(2(q)) for the multi-user cooperative communication systems. In particular, we consider a cooperative network with m users transmitting...
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In this paper, we present a decode-and-forward network coded (DFNC) scheme over GF(2(q)) for the multi-user cooperative communication systems. In particular, we consider a cooperative network with m users transmitting independent packets to the same destination. These users form a cooperation set to help each other by using linear network coding. We propose a coding coefficients construction method which can efficiently reduce the transmission overhead from m(q + log(2)m) to m bits compared with conventional random network coding. Furthermore, we propose a novel decoding algorithm-credit-based updating algorithm in order to improve the solvability of decoding set of equations at the destination. The proposed decoding algorithm is combined with channel decoding and is applied on symbol-level. It can fully make use of the error recovery property of network coding while conventional decoding algorithms (e.g., Gaussian elimination) overlook it. We theoretically analyze the diversity performance in terms of information outage probability, and the results show that diversity order of m + 1 can be achieved for a m-user cooperation system. Moreover, we conduct extensive simulations to show that DFNC outperforms other transmission schemes in terms of symbol error rate and achieves higher diversity order. We also demonstrate that the proposed decoding algorithm provides significant performance gain over conventional decoding algorithm.
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