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
Ao tentar estimar canais multipercursos variantes no tempo aplicando um modelo de expansão de base (BEM) em sistemas de multiplexação por divisão de frequência ortogonal (OFDM), os clusters piloto são contaminados por interferência entre portadoras (ICI). O cluster piloto ICI (PC-ICI) degrada a precisão da estimativa dos coeficientes BEM, o que degrada o desempenho do sistema. Neste artigo é proposto um esquema de supressão PC-ICI, no qual dois símbolos codificados definidos como somas ponderadas de símbolos de dados são inseridos em ambos os lados de cada cluster piloto. Supondo que o canal possua espectro Doppler plano, os coeficientes de peso otimizados são obtidos por um algoritmo de otimização iterativo alternado, de modo que a soma do PC-ICI gerado pelos símbolos codificados e pelos símbolos de dados seja minimizada. Ao aproximar os coeficientes de peso otimizados, eles são independentes da potência de tap do canal. Além disso, verifica-se que o esquema proposto é robusto ao erro de estimativa do offset de frequência Doppler normalizado e pode ser aplicado a canais com outros tipos de espectros Doppler. Os resultados da simulação numérica mostram que, em comparação com os esquemas convencionais, o esquema proposto alcança melhorias significativas no desempenho da supressão de PC-ICI, estimativa de canal e taxa de erro de bit do sistema (BER).
Yong DING
Xidian University,Guilin University of Electronic Technology
Shan OUYANG
Xidian University,Guilin University of Electronic Technology
Yue-Lei XIE
Guilin University of Electronic Technology
Xiao-Mao CHEN
Guilin University of Electronic Technology
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Yong DING, Shan OUYANG, Yue-Lei XIE, Xiao-Mao CHEN, "Pilot Cluster ICI Suppression in OFDM Systems Based on Coded Symbols" in IEICE TRANSACTIONS on Communications,
vol. E101-B, no. 11, pp. 2320-2330, November 2018, doi: 10.1587/transcom.2017EBP3473.
Abstract: When trying to estimate time-varying multipath channels by applying a basis expansion model (BEM) in orthogonal frequency division multiplexing (OFDM) systems, pilot clusters are contaminated by inter-carrier interference (ICI). The pilot cluster ICI (PC-ICI) degrades the estimation accuracy of BEM coefficients, which degrades system performance. In this paper, a PC-ICI suppression scheme is proposed, in which two coded symbols defined as weighted sums of data symbols are inserted on both sides of each pilot cluster. Under the assumption that the channel has Flat Doppler spectrum, the optimized weight coefficients are obtained by an alternating iterative optimization algorithm, so that the sum of the PC-ICI generated by the encoded symbols and the data symbols is minimized. By approximating the optimized weight coefficients, they are independent of the channel tap power. Furthermore, it is verified that the proposed scheme is robust to the estimation error of the normalized Doppler frequency offset and can be applied to channels with other types of Doppler spectra. Numerical simulation results show that, compared with the conventional schemes, the proposed scheme achieves significant improvements in the performance of PC-ICI suppression, channel estimation and system bit-error-ratio (BER).
URL: https://global.ieice.org/en_transactions/communications/10.1587/transcom.2017EBP3473/_p
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@ARTICLE{e101-b_11_2320,
author={Yong DING, Shan OUYANG, Yue-Lei XIE, Xiao-Mao CHEN, },
journal={IEICE TRANSACTIONS on Communications},
title={Pilot Cluster ICI Suppression in OFDM Systems Based on Coded Symbols},
year={2018},
volume={E101-B},
number={11},
pages={2320-2330},
abstract={When trying to estimate time-varying multipath channels by applying a basis expansion model (BEM) in orthogonal frequency division multiplexing (OFDM) systems, pilot clusters are contaminated by inter-carrier interference (ICI). The pilot cluster ICI (PC-ICI) degrades the estimation accuracy of BEM coefficients, which degrades system performance. In this paper, a PC-ICI suppression scheme is proposed, in which two coded symbols defined as weighted sums of data symbols are inserted on both sides of each pilot cluster. Under the assumption that the channel has Flat Doppler spectrum, the optimized weight coefficients are obtained by an alternating iterative optimization algorithm, so that the sum of the PC-ICI generated by the encoded symbols and the data symbols is minimized. By approximating the optimized weight coefficients, they are independent of the channel tap power. Furthermore, it is verified that the proposed scheme is robust to the estimation error of the normalized Doppler frequency offset and can be applied to channels with other types of Doppler spectra. Numerical simulation results show that, compared with the conventional schemes, the proposed scheme achieves significant improvements in the performance of PC-ICI suppression, channel estimation and system bit-error-ratio (BER).},
keywords={},
doi={10.1587/transcom.2017EBP3473},
ISSN={1745-1345},
month={November},}
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TY - JOUR
TI - Pilot Cluster ICI Suppression in OFDM Systems Based on Coded Symbols
T2 - IEICE TRANSACTIONS on Communications
SP - 2320
EP - 2330
AU - Yong DING
AU - Shan OUYANG
AU - Yue-Lei XIE
AU - Xiao-Mao CHEN
PY - 2018
DO - 10.1587/transcom.2017EBP3473
JO - IEICE TRANSACTIONS on Communications
SN - 1745-1345
VL - E101-B
IS - 11
JA - IEICE TRANSACTIONS on Communications
Y1 - November 2018
AB - When trying to estimate time-varying multipath channels by applying a basis expansion model (BEM) in orthogonal frequency division multiplexing (OFDM) systems, pilot clusters are contaminated by inter-carrier interference (ICI). The pilot cluster ICI (PC-ICI) degrades the estimation accuracy of BEM coefficients, which degrades system performance. In this paper, a PC-ICI suppression scheme is proposed, in which two coded symbols defined as weighted sums of data symbols are inserted on both sides of each pilot cluster. Under the assumption that the channel has Flat Doppler spectrum, the optimized weight coefficients are obtained by an alternating iterative optimization algorithm, so that the sum of the PC-ICI generated by the encoded symbols and the data symbols is minimized. By approximating the optimized weight coefficients, they are independent of the channel tap power. Furthermore, it is verified that the proposed scheme is robust to the estimation error of the normalized Doppler frequency offset and can be applied to channels with other types of Doppler spectra. Numerical simulation results show that, compared with the conventional schemes, the proposed scheme achieves significant improvements in the performance of PC-ICI suppression, channel estimation and system bit-error-ratio (BER).
ER -