Alam Menezes - Academia.edu (original) (raw)

Papers by Alam Menezes

Computers and Electrical Engineering

Orientadores: Jose Marcos Travassos Romano, Cristiano Magalhães PanazioDissertação (mestrado) - U... more Orientadores: Jose Marcos Travassos Romano, Cristiano Magalhães PanazioDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de ComputaçãoResumo: A presente dissertação apresenta um estudo da tecnologia dos rádios cognitivos bem como uma avaliação dos possíveis ganhos desta promissora técnica em relação aos atuais meios de acesso ao espectro eletromagnético. Numa segunda frente de trabalho, tratamos do problema de equalização cega no contexto de canais SIMO, com uma única entrada e múltiplas saídas. Propomos a predição linear multicanal como estrutura de equalização em sistemas OFDM e avaliamos por meio de simulações a viabilidade da técnica propostaAbstract: In this work, we provide a study of the cognitive radio technology and the potential gains that this technique may provide with regard to current electromagnetic spectrum access techniques. In a second workphase, we deal with the problem of blind equalization in the context of single inp...

Universidade Federal de Juiz de Fora, Sep 1, 2014

A presente dissertacao apresenta um estudo da tecnologia dos radios cognitivos bem como uma avali... more A presente dissertacao apresenta um estudo da tecnologia dos radios cognitivos bem como uma avaliacao dos possiveis ganhos desta promissora tecnica em relacao aos atuais meios de acesso ao espectro eletromagnetico. Numa segunda frente de trabalho, tratamos do problema de equalizacao cega no contexto de canais SIMO, com uma unica entrada e multiplas saidas. Propomos a predicao linear multicanal como estrutura de equalizacao em sistemas OFDM e avaliamos por meio de simulacoes a viabilidade da tecnica proposta Abstract

This paper introduce the forward linear prediction for equalization of OFDM systems in space time... more This paper introduce the forward linear prediction for equalization of OFDM systems in space time channels. We shown by simulations that linear prediction structure have better performance that MERRY algorithm both to exploit space time diversity than tracking channel variations along of time. Keywords— OFDM, Blind Channel Shortening, Linear Multichannel Prediction, SIMO, MERRY, Second Order Statistics, Time-Varying Channel.

Anais do XXXIX Simpósio Brasileiro de Telecomunicações e Processamento de Sinais

Anais de XXXIII Simpósio Brasileiro de Telecomunicações

Advances and Results in Speech, Estimation, Compression, Recognition, Filtering, and Processing, 2015

2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications, 2008

This paper describes a real-time data communication system in metallurgical controllers. It was d... more This paper describes a real-time data communication system in metallurgical controllers. It was developed an acquisition and communication circuit (PAC) to become available the data process through Ethernet via TCP/IP. A short description of the technologies used is presented, as well as the basic PAC architecture. Finally, the methodology of tests and obtained results are discussed.

In this paper, we make use of a blind adaptive linear predictor for channel shortening in single ... more In this paper, we make use of a blind adaptive linear predictor for channel shortening in single input multiple output (SIMO) channels. We compare our approach to the so-called MERRY blind channel shortener. We assess through simulations that our proposed approach provides faster convergence rate and it better exploits the spatio-temporal diversity present in the SIMO channels.

This contribution introduces a robust version of the multicarrier equalization by restoration of ... more This contribution introduces a robust version of the multicarrier equalization by restoration of redundance (MERY) algorithm for data communication through power line communication (PLC) channel corrupted by impulsive noise. The novelty is the introduction of a nonlinear and differentiable function into the cost function of MERRY algorithm. As a result, the proposed and named robust (R)-MERRY algorithm is less sensitive to the presence and hardness of impulsive noise. Simulation results reveal that bit error rate (BER) performance improvements can be attained in PLC scenarios. I. INTRODUCTION Broadband access in last miles is a great challenge in developing and underdeveloped countries due to the limited telecom infrastructures. In this scenario, power line communications (PLC) as well as wireless communication appear as interesting solutions to overcome the lack of capillarity. The cost for PLC deployment can be reduced because the infrastructure available for transmission and dist...

This paper outlines a hybrid OFDM synchronization technique for powerline communication. Initiall... more This paper outlines a hybrid OFDM synchronization technique for powerline communication. Initially, the timing and frequency offset are estimated by searching for the peak of an evaluated metric provided by a reference block transmitted at the beginning of each OFDM frame, and subsequently, autocorrelation properties induced at cyclic prefix on the time domain are exploited to maintain estimates of the timing and frequency offset without the use of a new reference block for synchronization purpose. This strategy is interesting because once a first synchronization of the first OFDM block (the start point of the frame) is accomplished, any loss in spectral efficiency will occur subsequently. Additionally, we propose an interesting strategy with low computational complexity to improve the timing and frequency estimates after synchronization is carried out at the beginning of the frame. Basically, this strategy consists of averaging the peaks spacing between successive peaks of the evaluated autocorrelation metric. Simulation results reveal good performance in PLC scenarios, specially in the cases of occurrences of impulsive noise.

Anais de XXXIII Simpósio Brasileiro de Telecomunicações

Computers and Electrical Engineering

Orientadores: Jose Marcos Travassos Romano, Cristiano Magalhães PanazioDissertação (mestrado) - U... more Orientadores: Jose Marcos Travassos Romano, Cristiano Magalhães PanazioDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de ComputaçãoResumo: A presente dissertação apresenta um estudo da tecnologia dos rádios cognitivos bem como uma avaliação dos possíveis ganhos desta promissora técnica em relação aos atuais meios de acesso ao espectro eletromagnético. Numa segunda frente de trabalho, tratamos do problema de equalização cega no contexto de canais SIMO, com uma única entrada e múltiplas saídas. Propomos a predição linear multicanal como estrutura de equalização em sistemas OFDM e avaliamos por meio de simulações a viabilidade da técnica propostaAbstract: In this work, we provide a study of the cognitive radio technology and the potential gains that this technique may provide with regard to current electromagnetic spectrum access techniques. In a second workphase, we deal with the problem of blind equalization in the context of single inp...

Universidade Federal de Juiz de Fora, Sep 1, 2014

A presente dissertacao apresenta um estudo da tecnologia dos radios cognitivos bem como uma avali... more A presente dissertacao apresenta um estudo da tecnologia dos radios cognitivos bem como uma avaliacao dos possiveis ganhos desta promissora tecnica em relacao aos atuais meios de acesso ao espectro eletromagnetico. Numa segunda frente de trabalho, tratamos do problema de equalizacao cega no contexto de canais SIMO, com uma unica entrada e multiplas saidas. Propomos a predicao linear multicanal como estrutura de equalizacao em sistemas OFDM e avaliamos por meio de simulacoes a viabilidade da tecnica proposta Abstract

This paper introduce the forward linear prediction for equalization of OFDM systems in space time... more This paper introduce the forward linear prediction for equalization of OFDM systems in space time channels. We shown by simulations that linear prediction structure have better performance that MERRY algorithm both to exploit space time diversity than tracking channel variations along of time. Keywords— OFDM, Blind Channel Shortening, Linear Multichannel Prediction, SIMO, MERRY, Second Order Statistics, Time-Varying Channel.

Anais do XXXIX Simpósio Brasileiro de Telecomunicações e Processamento de Sinais

Anais de XXXIII Simpósio Brasileiro de Telecomunicações

Advances and Results in Speech, Estimation, Compression, Recognition, Filtering, and Processing, 2015

2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications, 2008

This paper describes a real-time data communication system in metallurgical controllers. It was d... more This paper describes a real-time data communication system in metallurgical controllers. It was developed an acquisition and communication circuit (PAC) to become available the data process through Ethernet via TCP/IP. A short description of the technologies used is presented, as well as the basic PAC architecture. Finally, the methodology of tests and obtained results are discussed.

In this paper, we make use of a blind adaptive linear predictor for channel shortening in single ... more In this paper, we make use of a blind adaptive linear predictor for channel shortening in single input multiple output (SIMO) channels. We compare our approach to the so-called MERRY blind channel shortener. We assess through simulations that our proposed approach provides faster convergence rate and it better exploits the spatio-temporal diversity present in the SIMO channels.

This contribution introduces a robust version of the multicarrier equalization by restoration of ... more This contribution introduces a robust version of the multicarrier equalization by restoration of redundance (MERY) algorithm for data communication through power line communication (PLC) channel corrupted by impulsive noise. The novelty is the introduction of a nonlinear and differentiable function into the cost function of MERRY algorithm. As a result, the proposed and named robust (R)-MERRY algorithm is less sensitive to the presence and hardness of impulsive noise. Simulation results reveal that bit error rate (BER) performance improvements can be attained in PLC scenarios. I. INTRODUCTION Broadband access in last miles is a great challenge in developing and underdeveloped countries due to the limited telecom infrastructures. In this scenario, power line communications (PLC) as well as wireless communication appear as interesting solutions to overcome the lack of capillarity. The cost for PLC deployment can be reduced because the infrastructure available for transmission and dist...

This paper outlines a hybrid OFDM synchronization technique for powerline communication. Initiall... more This paper outlines a hybrid OFDM synchronization technique for powerline communication. Initially, the timing and frequency offset are estimated by searching for the peak of an evaluated metric provided by a reference block transmitted at the beginning of each OFDM frame, and subsequently, autocorrelation properties induced at cyclic prefix on the time domain are exploited to maintain estimates of the timing and frequency offset without the use of a new reference block for synchronization purpose. This strategy is interesting because once a first synchronization of the first OFDM block (the start point of the frame) is accomplished, any loss in spectral efficiency will occur subsequently. Additionally, we propose an interesting strategy with low computational complexity to improve the timing and frequency estimates after synchronization is carried out at the beginning of the frame. Basically, this strategy consists of averaging the peaks spacing between successive peaks of the evaluated autocorrelation metric. Simulation results reveal good performance in PLC scenarios, specially in the cases of occurrences of impulsive noise.

Anais de XXXIII Simpósio Brasileiro de Telecomunicações