The original paper is in English. Non-English content has been machine-translated and may contain typographical errors or mistranslations. ex. Some numerals are expressed as "XNUMX".
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The original paper is in English. Non-English content has been machine-translated and may contain typographical errors or mistranslations. Copyrights notice
Este artigo propõe máximo conjunto a posteriori (MAP) detecção e filtragem espacial para comunicações móveis MIMO-OFDM; ele oferece excelente desempenho do receptor mesmo em canais com interferência limitada. O processador conjunto proposto consiste em um gerador de log de verossimilhança e um equalizador MAP. O gerador de log de verossimilhança suprime a interferência co-canal filtrando espacialmente os sinais recebidos e fornece métricas de ramificação de candidatos a sinais transmitidos. Usando as métricas de ramificação, o equalizador MAP gera razões de verossimilhança logarítmica de bits codificados e executa a decodificação de canal com base no critério MAP. No primeiro estágio, o gerador de log de verossimilhança realiza a filtragem espaço-temporal (STF) dos sinais recebidos antes da transformada rápida de Fourier (FFT) e é referido como STF do tipo pré-FFT. A estimativa de parâmetros, incluindo coeficientes de derivação dos filtros espaço-temporais e respostas de impulso de canal equivalentes de sinais desejados, é baseada na decomposição de valores próprios de uma matriz de autocorrelação de ambos os sinais recebidos e transmitidos. Para melhorias adicionais, no segundo estágio, o gerador realiza a filtragem espacial (SF) da saída FFT e é denominado SF do tipo pós-FFT. A estimativa dos coeficientes de derivação dos filtros espaciais e das respostas ao impulso do canal emprega os mínimos quadrados recursivos (RLS) com suavização. A razão para mudar do STF do tipo pré-FFT para o SF do tipo pós-FFT é que o STF do tipo pré-FFT supera o SF do tipo pós-FFT com um número limitado de símbolos de preâmbulo, enquanto o SF do tipo pós-FFT supera o STF do tipo pré-FFT quando os símbolos de dados podem ser detectados de forma confiável e usado para a estimativa dos parâmetros. Observe que existem duas diferenças principais entre os esquemas proposto e convencional: uma é que o esquema proposto realiza o processamento em dois estágios do STF do tipo pré-FFT e do tipo SF pós-FFT, enquanto a outra é que o algoritmo de suavização é aplicado ao parâmetro estimativa do esquema proposto. Simulações computacionais demonstram que o esquema proposto pode alcançar excelente desempenho PER sob condições de canal com interferência limitada e que pode superar o processamento conjunto convencional do STF do tipo pré-FFT e do equalizador MAP.
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Fan LISHENG, Kazuhiko FUKAWA, Hiroshi SUZUKI, Satoshi SUYAMA, "MAP Receiver with Spatial Filters for Suppressing Cochannel Interference in MIMO-OFDM Mobile Communications" in IEICE TRANSACTIONS on Communications,
vol. E92-B, no. 5, pp. 1841-1851, May 2009, doi: 10.1587/transcom.E92.B.1841.
Abstract: This paper proposes joint maximum a posteriori (MAP) detection and spatial filtering for MIMO-OFDM mobile communications; it offers excellent receiver performance even over interference-limited channels. The proposed joint processor consists of a log likelihood generator and a MAP equalizer. The log likelihood generator suppresses cochannel interference by spatially filtering received signals and provides branch metrics of transmitted signal candidates. Using the branch metrics, the MAP equalizer generates log likelihood ratios of coded bits and performs channel decoding based on the MAP criterion. In the first stage, the log likelihood generator performs spatio-temporal filtering (STF) of the received signals prior to the fast Fourier transform (FFT) and is referred to as preFFT-type STF. Estimation of parameters including tap coefficients of the spatio-temporal filters and equivalent channel impulse responses of desired signals is based on the eigenvalue decomposition of an autocorrelation matrix of both the received and transmitted signals. For further improvement, in the second stage, the generator performs spatial filtering (SF) of the FFT output and is referred to as postFFT-type SF. Estimation of both tap coefficients of the spatial filters and channel impulse responses employs the recursive least squares (RLS) with smoothing. The reason for switching from preFFT-type STF into postFFT-type SF is that preFFT-type STF outperforms postFFT-type SF with a limited number of preamble symbols while postFFT-type SF outperforms preFFT-type STF when data symbols can be reliably detected and used for the parameter estimation. Note that there are two major differences between the proposed and conventional schemes: one is that the proposed scheme performs the two-stage processing of preFFT-type STF and postFFT-type SF, while the other is that the smoothing algorithm is applied to the parameter estimation of the proposed scheme. Computer simulations demonstrate that the proposed scheme can achieve excellent PER performance under interference-limited channel conditions and that it can outperform the conventional joint processing of preFFT-type STF and the MAP equalizer.
URL: https://global.ieice.org/en_transactions/communications/10.1587/transcom.E92.B.1841/_p
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@ARTICLE{e92-b_5_1841,
author={Fan LISHENG, Kazuhiko FUKAWA, Hiroshi SUZUKI, Satoshi SUYAMA, },
journal={IEICE TRANSACTIONS on Communications},
title={MAP Receiver with Spatial Filters for Suppressing Cochannel Interference in MIMO-OFDM Mobile Communications},
year={2009},
volume={E92-B},
number={5},
pages={1841-1851},
abstract={This paper proposes joint maximum a posteriori (MAP) detection and spatial filtering for MIMO-OFDM mobile communications; it offers excellent receiver performance even over interference-limited channels. The proposed joint processor consists of a log likelihood generator and a MAP equalizer. The log likelihood generator suppresses cochannel interference by spatially filtering received signals and provides branch metrics of transmitted signal candidates. Using the branch metrics, the MAP equalizer generates log likelihood ratios of coded bits and performs channel decoding based on the MAP criterion. In the first stage, the log likelihood generator performs spatio-temporal filtering (STF) of the received signals prior to the fast Fourier transform (FFT) and is referred to as preFFT-type STF. Estimation of parameters including tap coefficients of the spatio-temporal filters and equivalent channel impulse responses of desired signals is based on the eigenvalue decomposition of an autocorrelation matrix of both the received and transmitted signals. For further improvement, in the second stage, the generator performs spatial filtering (SF) of the FFT output and is referred to as postFFT-type SF. Estimation of both tap coefficients of the spatial filters and channel impulse responses employs the recursive least squares (RLS) with smoothing. The reason for switching from preFFT-type STF into postFFT-type SF is that preFFT-type STF outperforms postFFT-type SF with a limited number of preamble symbols while postFFT-type SF outperforms preFFT-type STF when data symbols can be reliably detected and used for the parameter estimation. Note that there are two major differences between the proposed and conventional schemes: one is that the proposed scheme performs the two-stage processing of preFFT-type STF and postFFT-type SF, while the other is that the smoothing algorithm is applied to the parameter estimation of the proposed scheme. Computer simulations demonstrate that the proposed scheme can achieve excellent PER performance under interference-limited channel conditions and that it can outperform the conventional joint processing of preFFT-type STF and the MAP equalizer.},
keywords={},
doi={10.1587/transcom.E92.B.1841},
ISSN={1745-1345},
month={May},}
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TY - JOUR
TI - MAP Receiver with Spatial Filters for Suppressing Cochannel Interference in MIMO-OFDM Mobile Communications
T2 - IEICE TRANSACTIONS on Communications
SP - 1841
EP - 1851
AU - Fan LISHENG
AU - Kazuhiko FUKAWA
AU - Hiroshi SUZUKI
AU - Satoshi SUYAMA
PY - 2009
DO - 10.1587/transcom.E92.B.1841
JO - IEICE TRANSACTIONS on Communications
SN - 1745-1345
VL - E92-B
IS - 5
JA - IEICE TRANSACTIONS on Communications
Y1 - May 2009
AB - This paper proposes joint maximum a posteriori (MAP) detection and spatial filtering for MIMO-OFDM mobile communications; it offers excellent receiver performance even over interference-limited channels. The proposed joint processor consists of a log likelihood generator and a MAP equalizer. The log likelihood generator suppresses cochannel interference by spatially filtering received signals and provides branch metrics of transmitted signal candidates. Using the branch metrics, the MAP equalizer generates log likelihood ratios of coded bits and performs channel decoding based on the MAP criterion. In the first stage, the log likelihood generator performs spatio-temporal filtering (STF) of the received signals prior to the fast Fourier transform (FFT) and is referred to as preFFT-type STF. Estimation of parameters including tap coefficients of the spatio-temporal filters and equivalent channel impulse responses of desired signals is based on the eigenvalue decomposition of an autocorrelation matrix of both the received and transmitted signals. For further improvement, in the second stage, the generator performs spatial filtering (SF) of the FFT output and is referred to as postFFT-type SF. Estimation of both tap coefficients of the spatial filters and channel impulse responses employs the recursive least squares (RLS) with smoothing. The reason for switching from preFFT-type STF into postFFT-type SF is that preFFT-type STF outperforms postFFT-type SF with a limited number of preamble symbols while postFFT-type SF outperforms preFFT-type STF when data symbols can be reliably detected and used for the parameter estimation. Note that there are two major differences between the proposed and conventional schemes: one is that the proposed scheme performs the two-stage processing of preFFT-type STF and postFFT-type SF, while the other is that the smoothing algorithm is applied to the parameter estimation of the proposed scheme. Computer simulations demonstrate that the proposed scheme can achieve excellent PER performance under interference-limited channel conditions and that it can outperform the conventional joint processing of preFFT-type STF and the MAP equalizer.
ER -