Future wireless communication systems require efficient and flexible baseband receivers. Meaningful efficiency metrics are key for design space exploration to quantify the algorithmic and the implementation complexity...
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Future wireless communication systems require efficient and flexible baseband receivers. Meaningful efficiency metrics are key for design space exploration to quantify the algorithmic and the implementation complexity of a receiver. Most of the current established efficiency metrics are based on counting operations, thus neglecting important issues like data and storage complexity. In this paper we introduce suitable energy and area efficiency metrics which resolve the afore-mentioned disadvantages. These are decoded information bit per energy and throughput per area unit. Efficiency metrics are assessed by various implementations of turbo decoders, LDPC decoders and convolutional decoders. An exploration approach is presented, which permit an appropriate benchmarking of implementation efficiency, communications performance, and flexibility trade-offs. Two case studies demonstrate this approach and show that design space exploration should result in various efficiency evaluations rather than a single snapshot metric as done often in state-of-the-art approaches.
Depth-first tree search with multiple radii (DFTS-MR) algorithm attains significant complexity reduction over DFTS with a single radius (DFTS-SR) for solving integer least-squares (ILS) problems. Herein, we derive the...
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Depth-first tree search with multiple radii (DFTS-MR) algorithm attains significant complexity reduction over DFTS with a single radius (DFTS-SR) for solving integer least-squares (ILS) problems. Herein, we derive the lower bound on the expected complexity of DFTS-MR under i.i.d. complex Gaussian environments. Currently, the upper bound on the expected DFTS-MR complexity is known. Our analytical result shows the computational dependence on the statistics of the channel, the noise, and the transmitted symbols. It also reflects the use of multiple radii, which is one of the main characteristics of DFTS-MR. The resultant lower bound provides an efficient means to better understand the complexity behavior of DFTS-MR, along with the (known) upper bound.
The large deviation properties of the Lempel-Ziv complexity are studied using a one-dimensional non-hyperbolic chaos map called the "modified Bernoulli map", where the transition between stationary and non-s...
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The large deviation properties of the Lempel-Ziv complexity are studied using a one-dimensional non-hyperbolic chaos map called the "modified Bernoulli map", where the transition between stationary and non-stationary chaos is clearly observed. The upper limit of the Lempel-Ziv complexity in the non-stationary regime is theoretically evaluated, and the relationship between the algorithmic complexity and the Lempel-Ziv complexity is discussed. Non-stationary processes are universal phenomena in non-hyperbolic systems, and they are usually characterized by an infinite ergodic measure and intrinsic long time tails, such as 1/f(nu) spectral fluctuations. It is shown that the Lempel-Ziv complexity obeys universal sealing laws and that the Lempel-Ziv complexity has the L-1-function property, which guarantees the Darling-Kac-Aaronson theorem for an infinite ergodic system. The most striking result is that the maximum diversity appears at the transition point from stationary chaos to non-stationary chaos where the exact 1/f spectral process is generated.
A stably bounded hypergraph H is a hypergraph together with four color-bound functions s, t, a and b, each assigning positive integers to the edges. A vertex coloring of H is considered proper if each edge E has at le...
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A stably bounded hypergraph H is a hypergraph together with four color-bound functions s, t, a and b, each assigning positive integers to the edges. A vertex coloring of H is considered proper if each edge E has at least s(E) and at most t(E) different colors assigned to its vertices, moreover each color occurs on at most b(E) vertices of E, and there exists a color which is repeated at least a(E) times inside E. The lower and the upper chromatic number of H is the minimum and the maximum possible number of colors, respectively, over all proper colorings. An interval hypergraph is a hypergraph whose vertex set allows a linear ordering such that each edge is a set of consecutive vertices in this order. We study the time complexity of testing colorability and determining the lower and upper chromatic numbers. A complete solution is presented for interval hypergraphs without overlapping edges. complexity depends both on problem type and on the combination of color-bound functions applied, except that all the three coloring problems are NP-hard for the function pair a, b and its extensions. For the tractable classes, linear-time algorithms are designed. It also depends on problem type and function set whether complexity jumps from polynomial to NP-hard if the instance is allowed to contain overlapping intervals. Comparison is facilitated with three handy tables which also include further structure classes. (C) 2012 Elsevier B.V. All rights reserved.
Different aspects of the predictability problem in dynamical systems are reviewed. The deep relation among Lyapunov exponents, Kolmogorov-Sinai entropy, Shannon entropy and algorithmic complexity is discussed. In part...
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Different aspects of the predictability problem in dynamical systems are reviewed. The deep relation among Lyapunov exponents, Kolmogorov-Sinai entropy, Shannon entropy and algorithmic complexity is discussed. In particular, we emphasize how a characterization of the unpredictability of a system gives a measure of its complexity. Adopting this point of view, we review some developments in the characterization of the predictability of systems showing different kinds of complexity: from low-dimensional systems to high-dimensional ones with spatio-temporal chaos and to fully developed turbulence. A special attention is devoted to finite-time and finite-resolution effects on predictability, which can be accounted with suitable generalization of the standard indicators. The problems involved in systems with intrinsic randomness is discussed, with emphasis on the important problems of distinguishing chaos from noise and of modeling the system. The characterization of irregular behavior in systems with discrete phase space is also considered. (C) 2002 Elsevier Science B.V. All rights reserved.
Two conjectures, drawn from Gregory Chaitin's algorithmic Information Theory, are examined with respect to the relationship between an algorithm and its product;in particular his finding that, where an algorithm i...
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Two conjectures, drawn from Gregory Chaitin's algorithmic Information Theory, are examined with respect to the relationship between an algorithm and its product;in particular his finding that, where an algorithm is minimal, its length provides a measure of the complexity of the product. algorithmic complexity is considered from the perspective of the relationship between genotype and phenotype, which Chaitin suggests is analogous to other algorithm-product systems. The first conjecture is that the genome is a minimal set of algorithms for the phenotype. Evidence is presented for a factor, here termed 'genetic parsimony', which is thought to have helped minimize the growth of genome size during evolution. Species that depend on rapid replication, such as prokaryotes which are generally r-selected are more likely to have small genomes, while the K-strategists accumulate introns and have large genomes. The second conjecture is that genome size could provide a measure of organism complexity. A surrogate index for coding DNA is in agreement with an established phenotypic index (number of cell types), in exhibiting an evolutionary trend of increasing organism complexity over time. Evidence for genetic parsimony indicates that simplicity in coding has been selected, and is responsible for phenotypic order. It is proposed that order evolved because order in the phenotype can be encoded more economically than disorder. Thus order arises due to selection for genetic parsimony, as does the evolution of other 'emergent' properties.
If (X,T) is a measure-preserving system, ct a nontrivial partition of X into two sets and f a positive increasing function defined on the positive real numbers, then the limit inferior of the sequence (2H(alpha (n-1)(...
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If (X,T) is a measure-preserving system, ct a nontrivial partition of X into two sets and f a positive increasing function defined on the positive real numbers, then the limit inferior of the sequence (2H(alpha (n-1)(0))/f(n))(n=1)(infinity) is greater than or equal to the limit inferior of the sequence of quotients of the average complexity of trajectories of length n generated by alpha (n-1)(0) and nf(log(2)(n))/(log(2)(n). A similar statement. also holds for the limit superior.
Deleting a node from an AVL tree of n nodes requires time O(log n). Typically, the operation may require O(log n) space, because a path of nodes from the root of the tree to the node being deleted must be maintained. ...
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Deleting a node from an AVL tree of n nodes requires time O(log n). Typically, the operation may require O(log n) space, because a path of nodes from the root of the tree to the node being deleted must be maintained. Sometimes, this stack is maintained separately;sometimes it is maintained using an extra pointer field in each node on the path (which points to its parent) together with a one-bit field that indicates whether the node is the left or right son of its parent. This article outlines a technique that eliminates completely the need for extra space for the stack.
We discuss a Neural Network model generating activation signals for locomotion in ants. The signals are chaotic and so are the temporal patterns of spontaneous activations in single ants. Active ants are able to move ...
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We discuss a Neural Network model generating activation signals for locomotion in ants. The signals are chaotic and so are the temporal patterns of spontaneous activations in single ants. Active ants are able to move and interact with other nest mates. This process of movement-interaction generates periodic pulses of activity once the number of individuals reaches a certain density value. An algorithmic complexity measure is used for identifying accurately the transition from chaos into order. Finally, an Iterated Function System analysis reveals the richness of dynamical behavior that emerges when ant colonies are self-poised near such a transition.
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