Pilot Cluster ICI Suppression in OFDM Systems Based on Coded Symbols

Yong DING; Shan OUYANG; Yue-Lei XIE; Xiao-Mao CHEN

doi:10.1587/transcom.2017EBP3473

Pilot Cluster ICI Suppression in OFDM Systems Based on Coded Symbols

Yong DING, Shan OUYANG, Yue-Lei XIE, Xiao-Mao CHEN

Full Text Views

0

Cite this

Summary :

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).

Publication: IEICE TRANSACTIONS on Communications Vol.E101-B No.11 pp.2320-2330

Publication Date: 2018/11/01

Publicized: 2018/04/27

Online ISSN: 1745-1345

DOI: 10.1587/transcom.2017EBP3473

Type of Manuscript: PAPER

Category: Wireless Communication Technologies

Authors

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

Keyword

orthogonal frequency division multiplexing (OFDM), channel estimation, pilot cluster ICI suppression, coded symbol, alternating iterative optimization

Cite this

Copy

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

Copy

@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},}

Copy

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 -