一种抗脉冲噪声的宽带电力线通信系统信道估计算法
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摘要
基于正交频分复用(orthogonal frequency division multiplexing,OFDM)的宽带电力线通信(power line communication,PLC)系统中信道估计受到了脉冲噪声的严重影响。针对该问题提出了一种确定脉冲噪声出现位置的方法,对其进行"置零"处理。该时域非线性处理虽然消除了脉冲噪声的影响,但引入了子载波间干扰(inter carrier interference,ICI),造成信道估计性能的损失,利用PLC系统中的前导结构设计了一种迭代消除ICI的信道估计算法。仿真结果表明,由于进一步考虑了ICI对信道估计的影响,所提算法显著提高了PLC系统脉冲噪声环境下信道估计的准确性,相应改善了该系统的误码性能。
Channel estimation in OFDM-based wide band power line communication( WB-PLC) system is severely impacted by impulse noise. In order to solve this problem,a method to determine the position of impulse noise is firstly proposed and then"null"processing is carried out. Although the time domain nonlinear processing eliminates the impact of impulse noise,it causes the inter carrier interference( ICI) and results in the loss of channel estimation performance. Therefore,a channel estimation algorithm using preamble in PLC system to eliminate the ICI iteratively is designed. Simulation results show that furtherly considering the influence of ICI on channel estimation,the proposed algorithm significantly improves the accuracy of channel estimation under the impulse noise environment and correspondingly improves the BER performance in PLC system.
Channel estimation in OFDM-based wide band power line communication( WB-PLC) system is severely impacted by impulse noise. In order to solve this problem,a method to determine the position of impulse noise is firstly proposed and then"null"processing is carried out. Although the time domain nonlinear processing eliminates the impact of impulse noise,it causes the inter carrier interference( ICI) and results in the loss of channel estimation performance. Therefore,a channel estimation algorithm using preamble in PLC system to eliminate the ICI iteratively is designed. Simulation results show that furtherly considering the influence of ICI on channel estimation,the proposed algorithm significantly improves the accuracy of channel estimation under the impulse noise environment and correspondingly improves the BER performance in PLC system.
引文
[1] ZHANG J,MENG J. Noise Resistant OFDM for PowerLine Communication Systems[J]. IEEE Transactions on Power Delivery,2010,25(2):693-701.
[2] YASUI H,NAKAMURA A,ITAMI M. Efficient Channel Estimation Scheme under Impulsive Noise Environment[J]. Ite Transactions on Media Technology&Applications,2016,4(2):177-185.
[3] ZHIDKOV S V. Analysis and Comparison of Several Simple Impulsive Noise Mitigation Schemes for OFDM Receivers[J]. IEEE Transactions on Communications,2008,56(1):5-9.
[4] ZHIDKOV S V. Impulsive Noise Suppression in OFDMbased Communication Systems[J]. IEEE Transactions on Consumer Electronics,2003,49(4):944-948.
[5] YIH C H. Iterative Interference Cancellation for OFDM Signals with Blanking Nonlinearity in Impulsive Noise Channels[J]. IEEE Signal Processing Letters,2012,19(3):147-150.
[6] JUWONO F H,GUO Q,HUANG D,et al. Deep Clipping for Impulsive Noise Mitigation in OFDM-based Power-Line Communications[J]. IEEE Transactions on Power Delivery,2014,29(3):1335-1343.
[7]王丛慧.低压电力线OFDM通信系统信道估计技术的研究[D].秦皇岛:燕山大学,2016.WANG Conghui. Research on Channel Estimation Technology of Low Voltage Power Line OFDM Communication System[D]. Qinhuangdao:Yanshan University,2016.
[8]肖勇,房莹,张捷,等.低压电力线载波通信信道特性研究[J].电力系统保护与控制,2012(20):20-25.XIAO Yong,FANG Ying,ZHANG Jie,et al. Research on Characteristics of Low Voltage Power Line Communication Channel[J]. Power System Protection and Control,2012(20):20-25.
[9]谢斌,陈琴,杨丽清.一种结合DWT与DCT插值的OFDM信道估计新方法[J].江苏大学学报:自然科学版,2017,38(3):313-318.XIE Bin,CHEN Qin,YANG Liqing. A new method for channel estimation of OFDM based on DWT and DCT interpolation[J].Journal of Jiangsu University:Natural Science Editions,2017,38(3):313-318.
[10] ABURAKHIA S A,BADRAN E F,MOHAMED D A.Distribution of the PAPR for Real-Valued OFDM Signals[C]//International Conference on Information Technology. Las Vegas:IEEE Press,2009:2.
[11] CORTES J A,CANETE F J,DIEZ L,et al. On PLC Channel Models:An OFDM-based Comparison[C]//IEEE International Symposium on Power Line Communications and ITS Applications. Johannesburg:IEEE Press,2013:333-338.
[2] YASUI H,NAKAMURA A,ITAMI M. Efficient Channel Estimation Scheme under Impulsive Noise Environment[J]. Ite Transactions on Media Technology&Applications,2016,4(2):177-185.
[3] ZHIDKOV S V. Analysis and Comparison of Several Simple Impulsive Noise Mitigation Schemes for OFDM Receivers[J]. IEEE Transactions on Communications,2008,56(1):5-9.
[4] ZHIDKOV S V. Impulsive Noise Suppression in OFDMbased Communication Systems[J]. IEEE Transactions on Consumer Electronics,2003,49(4):944-948.
[5] YIH C H. Iterative Interference Cancellation for OFDM Signals with Blanking Nonlinearity in Impulsive Noise Channels[J]. IEEE Signal Processing Letters,2012,19(3):147-150.
[6] JUWONO F H,GUO Q,HUANG D,et al. Deep Clipping for Impulsive Noise Mitigation in OFDM-based Power-Line Communications[J]. IEEE Transactions on Power Delivery,2014,29(3):1335-1343.
[7]王丛慧.低压电力线OFDM通信系统信道估计技术的研究[D].秦皇岛:燕山大学,2016.WANG Conghui. Research on Channel Estimation Technology of Low Voltage Power Line OFDM Communication System[D]. Qinhuangdao:Yanshan University,2016.
[8]肖勇,房莹,张捷,等.低压电力线载波通信信道特性研究[J].电力系统保护与控制,2012(20):20-25.XIAO Yong,FANG Ying,ZHANG Jie,et al. Research on Characteristics of Low Voltage Power Line Communication Channel[J]. Power System Protection and Control,2012(20):20-25.
[9]谢斌,陈琴,杨丽清.一种结合DWT与DCT插值的OFDM信道估计新方法[J].江苏大学学报:自然科学版,2017,38(3):313-318.XIE Bin,CHEN Qin,YANG Liqing. A new method for channel estimation of OFDM based on DWT and DCT interpolation[J].Journal of Jiangsu University:Natural Science Editions,2017,38(3):313-318.
[10] ABURAKHIA S A,BADRAN E F,MOHAMED D A.Distribution of the PAPR for Real-Valued OFDM Signals[C]//International Conference on Information Technology. Las Vegas:IEEE Press,2009:2.
[11] CORTES J A,CANETE F J,DIEZ L,et al. On PLC Channel Models:An OFDM-based Comparison[C]//IEEE International Symposium on Power Line Communications and ITS Applications. Johannesburg:IEEE Press,2013:333-338.