Alocação de Potência Adaptativa para Maximização da Eficiência Espectral Sujeita a Restrições de Satisfação

Weskley Vinicius Fernandes Mauricio, Francisco Rafael Marques Lima, Tarcísio Ferreira Maciel, Francisco Rodrigo Porto Cavalcanti

DOI: 10.14209/sbrt.2015.54

Keywords: Radio Resource Allocation Power Allocation Quality of Service

Abstract

In this work we revisit the radio resource alocation problem of maximizing the total transmit data rate subject to satisfaction guarantees in terms of QoS. It was previously studied on the perspective of resource block assignment (only) considering equal power allocation and, herein, we study this problem assuming adaptive power allocation. One of the contri- butions of this work is the formulation of the studied problem as a non-linear integer optimization problem. Then, based on reasonable assumptions and some algebraic operations we were able to convert this problem to an integer and linear optimization problem. Through the analysis of the optimal solution that was obtained by means of computational simulations, we are able to assess the possible performance gains that could be obtained due to the use of adaptive power allocation in terms of QoS guarantees.

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On modeling power-line communication noise

Victor Fernandes, Sanja Angelova, Weiler A. Finamore, Moises V. Ribeiro

DOI: 10.14209/sbrt.2015.55

Keywords: Power line communication Power line noise Noise parameter estimation.

Abstract

This article introduces an algorithm to estimate pa- rameters of measured power line noise modeled as the Bernoul li- Gaussian noise. These are important parameters when design ing power line communications systems. Tests with several samp les of noise registered during a measure campaign in the city of Juiz de Fora, MG, were performed and the parameters of these measured noise are obtained. Tests with synthetic noise gen erated according to the Bernoulli model for power line noise are a go od evidence of the algorithm effectiveness.

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Ampliação de Ganho de Codificação em um Código EFEC BCH para Comunicações Ópticas

Diego Brito de Carvalho, Arley Henrique Salvador, Érico Nunes Ferreira Bastos, Luiz Juberto Rossi de Jesus, Max H. M. Cost

DOI: 10.14209/sbrt.2015.56

Keywords: Error Correcting Code BCH EFEC Recommendation ITU G.975.1 – Annex I.9 Optical Communication

Abstract

Due to factors such as the growing number of internet-connected devices, the core of optical communication networks is suffering great increase in traffic. Therefore, studying alternatives that provide more capacity and robustness to these networks, including improved error correcting codes, is of fundamental importance. This paper presents data of an FPGA implementation of a BCH code derived from the channel code proposed in Annex I.9 of ITU-T Recommendation G.975.1 [1]. By increasing redundancy (parity) and by reorganizing frame structures, the new code produces a higher coding gain than the original code.

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Performance of Maximum Eigenvalue Spectrum Sensing over α - μ , κ - μ and η - μ Fading Channels

Carlos Rafael Nogueira da Silva, Michel Daoud Yacoub, Dayan Adionel Guimarães

DOI: 10.14209/sbrt.2015.59

Keywords: Cognitive radio eigenvalue spectrum sensing gen- eralized fading channels

Abstract

Eigenvalue spectrum sensing is a powerful tech- nique to search for spectrum holes, with performance similar to the energy detection. Among the eigenvalue-based techniques, the maximum eigenvalue detection (MED), also known as Roy’s Largest Root Test (RLRT) is, for a sufficiently large number of samples, the optimum test if there is no a priori knowledge on the primary signal. In this paper, the probability of detection of the MED is assessed, assuming that the primary signal is transmitted over the α - μ , κ - μ and η - μ generalized fading channels.

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Eficiência Energética em Redes de Sensores Two-Way com Seleção de Relays

Nathalia dos Santos Silva, Lucas Dias Hiera Sampaio, Taufik Abrão

DOI: 10.14209/sbrt.2015.60

Keywords: Max Min Cooperative Networks Outage Proba- bility Energy Efficiency Wireless Sensors Network

Abstract

This paper analyses the dependence between outage probability and energy efficiency in wireless sensors networks with relay selection procedures. Considering different criteria like the best use of network resources such as spectrum and energy, it is possible to imply which relay selection scheme is the most appropriate for each practical scenario, if a single relay or multiple relays is more suitable. Our numerical expressions for the associated outage probability and energy efficiency are pre- sented while numerical results obtained through computational simulations corroborate the mathematical expressions. Finally, implications about the best transmission scheme are offered for each network configuration discussed.

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Considerações para a Implementaçãode Power Line Communications para Aplicações de Smart Grid

Hening Almeida de Andrade, Rafael Moura Duarte, Fabrício Braga Soares de Carvalho, Fabiano Salvadori, Waslon Terllizzie Araújo Lopes

DOI: 10.14209/sbrt.2015.61

Keywords: Power Line Communications Circuits Simulations

Abstract

This work presents a study of the transmission of data via PLC (Power Line Communications) technology. The objective is to design circuits to implement the communication for Smart Grid. In the proposed project, some important operational parameters are defined and the preliminary results obtained from the simulation of the proposed PLC communication are highlighted.

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Studying the compression performance of video descriptors

Renam C. da Silva, Fernando Pereira, Eduardo A. B. da Silva

DOI: 10.14209/sbrt.2015.63

Keywords: Visual features descriptors compression SIFT SURF

Abstract

The main objective of this paper is to study the per- formance of a framework for encoding visual feature descriptor s. Local visual feature descriptors are employed in a number of computer vision tasks, e.g. image and video retrieval by visual search, object recognition and automatic annotation. In scenar ios strictly constrained in terms of storage capability, memory and network resources such as those observed in visual sensor networks and mobile visual search applications, compression may be imperative. We evaluate coding schemes for the two most used feature descriptors, namely Scale Invariant Feature Transform (SIFT) and Speeded Up Robust Features (SURF). The coding modes include intra- and inter-frame modes, with and without decorrelating transforms. They are tested in descriptors extra cted from video sequences with different content characteristics. A detailed rate-distortion analysis is conducted in order to assess the contribution of each coding mode. Also, is shown that rate- distortion optimization with all coding mode enabled leads to best results.

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Classification of the perfect codes in the ∞ -Lee metric

Claudio M. Qureshi, Sueli I. R. Costa

DOI: 10.14209/sbrt.2015.64

Keywords: Perfect codes Lee metric p -Lee metric group isomorphism

Abstract

This paper is concerned with perfect codes in the ∞ -Lee metric. A complete classification and description of all (linear and non-linear) two-dimensional perfect codes in the ∞ - Lee metric is presented. Moreover, in the linear case we construct a generator matrix for these codes which induces an isomorphism between the code and an abelian group of the form Z a × Z b with a | b and we determine all possible group structures that can be represented for such codes. We also present an algorithm to obtain a q -ary perfect code with a given group structure and two methods of construction of perfect codes in the ∞ -Lee metric from codes of smaller dimension. In particular, these methods allow us to construct interesting families of perfect ∞ -Lee codes including n -dimensional cyclic perfect codes for all n .

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Perfil de alocação Logarítmico Adaptativo dos Coeficientes da TWD para Compressão de S-EMG

Marcel H. Trabuco, Marcus V. C. C osta, Francisco A. de O. Nasc iment

DOI: 10.14209/sbrt.2015.62

Keywords: Data compression Wavelet transform Surface electromyographic sign al Adaptive protoco

Abstract

This article presents a surface electromyography signal compression algorithm based on wavelet transform and sub-band adaptive bit allocation. The proposal is an allocation profile that fits a logarithmic curve according to the energy o f each sub-band. The results obtained, compared to others previous works found in literature, outperforms those in a wide range of objective evaluation metrics

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Some Reflections on the 35 Years of the Constant Modulus Criterion

Ricardo Suyama, Romis Attux, Denis Fantinato, Jo ão Marcos T. Roman

DOI: 10.14209/sbrt.2015.65

Keywords: Unsupervised equalization constant modulus criterion CMA

Abstract

This work, which is intended to be a celebration to the 35 years of the constant modulus criterion and to the impact it had in the development of our research group, pr esents both tutorial elements and a discussion of published and unpublished results that, hopefully, will generate new reflecti ons and perspectives on this important topic

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