引入加权系数消除ICI的二次快时变信道估计算法
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摘要
针对高速移动环境下由多普勒频移引起的子载波间干扰(inter-carrier interference,ICI),提出一种引入加权系数消除ICI的二次快时变信道估计算法。该算法进行两次信道估计,第一次估计用于提供信道状态信息,在保证符号率的前提下消除ICI,第二次估计在ICI消除的情况下进行,可以提高信道估计精度;并对简化的并行干扰消除(parallel interference cancellation,PIC)算法进行改进,基于最小均方误差准则引入加权系数,使得ICI消除后的残余误差最小。仿真结果和理论分析达到很好的一致性,当信道信噪比为0 d B时,归一化均方误差(normalized mean square error,NMSE)性能增益最大约为0. 071 4,提高了快时变信道估计的精度。
This paper proposed a twice channel estimation algorithm,in which used weighted coefficient to cancel ICI caused by Doppler frequency shift in high speed mobile environment. The algorithm achieved twice channel estimation. The first estimation provided channel state information to cancel the ICI under the premise of ensuring the symbol rate. In the case of ICI cancellation,the second estimation enhanced the channel estimation accuracy. Then the algorithm improved the simplified PIC algorithm,and introduced the weighting coefficient to make the residual error smallest after ICI cancellation based on the minimum mean square error criterion. The simulation results are in good agreement with the theoretical analysis. The proposed algorithm improves the estimation accuracy of rapidly time-varying channels. The maximum value of NMSE performance gain is0. 071 4,when the SNR is 0 dB.
This paper proposed a twice channel estimation algorithm,in which used weighted coefficient to cancel ICI caused by Doppler frequency shift in high speed mobile environment. The algorithm achieved twice channel estimation. The first estimation provided channel state information to cancel the ICI under the premise of ensuring the symbol rate. In the case of ICI cancellation,the second estimation enhanced the channel estimation accuracy. Then the algorithm improved the simplified PIC algorithm,and introduced the weighting coefficient to make the residual error smallest after ICI cancellation based on the minimum mean square error criterion. The simulation results are in good agreement with the theoretical analysis. The proposed algorithm improves the estimation accuracy of rapidly time-varying channels. The maximum value of NMSE performance gain is0. 071 4,when the SNR is 0 dB.
引文
[1] Wu Jingxian,Fan Pingzhi. A survey on high mobility wireless communications:challenges,opportunities and solutions[J]. IEEE Access,2016,4:450-476.
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[3] Mostofi Y,Cox D C. ICI mitigation for pilot-aided OFDM mobile systems[J]. IEEE Trans on Wireless Communications,2005,4(2):765-774.
[4] Hao Jinxing,Wang Jintao,Pan Changyong. Low complexity ICI mitigation for MIMO-OFDM in time-varying channels[J]. IEEE Trans on Broadcasting,2016,62(3):1-9.
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[7] Bi Yuming,Zhang Jianhua,Zeng Ming,et al. Channel modeling and estimation for OFDM systems in high-speed trains scenarios[C]//Proc of the 83rd IEEE Vehicular Technology Conference. Piscataway,NJ:IEEE Press,2016:1-6.
[8] Aboutorab N,Hardjawana W,Vucetic B. A new iterative Doppler-assisted channel estimation joint with parallel ICI cancellation for highmobility MIMO-OFDM systems[J]. IEEE Trans on Vehicular Technology,2012,61(4):1577-1589.
[9] Liao Jialing,Qiao Gang,Ma Xuefei. A novel parallel interference cancellation scheme for OFDM in time-varying underwater acoustic channels[C]//Proc of International Conference on Mechatronic Sciences,Electric Engineering and Computer. Piscataway,NJ:IEEE Press,2013:3692-3696.
[10]Liu Chun Hao,Chuang Gene C H. Joint ICI cancellation and channel estimation with real-time channel adaptation for high-mobility OFDM systems[C]//Proc of GLOBECOM Workshops. Piscataway,NJ:IEEE Press,2011:1376-1381.
[11]Nissel R,Rupp M. Doubly-selective MMSE channel estimation and ICI mitigation for OFDM systems[C]//Proc of IEEE International Conference on Communications. Piscataway,NJ:IEEE Press,2015:4692-4697.
[12] Tang Z,Cannizzaro R C,Leus G,et al. Pilot-assisted time-varying channel estimation for OFDM systems[J]. IEEE Trans on Signal Processing,2007,55(5):2226-2238.
[13] Guo Qilin,Wu Muqing,Zhang Qinjuan,et al. Iterative decomposed OFDM channel estimation algorithm over highly mobile channels[J].Wireless Personal Communications,2013,71(2):1137-1158.
[14] Tomasin S,Gorokhov A,Yang Haibing,et al. Iterative interference cancellation and channel estimation for mobile OFDM[J]. IEEE Trans on Wireless Communications,2005,4(1):238-245.
[15]Zemen T,Mecklenbrauker C F. Time-variant channel estimation using discrete prolate spheroidal sequences[J]. IEEE Trans on Signal Processing,2005,53(9):3597-3607.
[16]enol H. Joint channel estimation and symbol detection for OFDM systems in rapidly time-varying sparse multipath channels[J]. Wireless Personal Communications,2015,82(3):1161-1178.
[17]Teo K A D,Ohno S. Optimal MMSE finite parameter model for doublyselective channels[C]//Proc of IEEE Global Telecommunications Conference. Piscataway,NJ:IEEE Press,2005.
[18]尼俊红,刘泽民.基于MMSE准则的改进型并行迭代ICI消除算法[J].电路与系统学报,2011,16(1):74-78.(Ni Junhong,Liu Zeming. Improved parallel iterative ICI cancellation algorithm based on MMSE criterion[J]. Journal of Circuits and Systems,2011,16(1):74-78.)
[19]Sheng Zhichao,Fang Yong,Wang Chen. A BEM method of channel estimation for OFDM systems in high-speed train environment[C]//Proc of International Workshop on High Mobility Wireless Communications. Piscataway,NJ:IEEE Press,2013:6-9.
[2] Jeon W G,Chan K H,Cho Y S. An equalization technique for OFDM systems in time-variant multipath channels[J]. IEEE Trans on Communications,1999,47(1):27-32.
[3] Mostofi Y,Cox D C. ICI mitigation for pilot-aided OFDM mobile systems[J]. IEEE Trans on Wireless Communications,2005,4(2):765-774.
[4] Hao Jinxing,Wang Jintao,Pan Changyong. Low complexity ICI mitigation for MIMO-OFDM in time-varying channels[J]. IEEE Trans on Broadcasting,2016,62(3):1-9.
[5] Zafarani E,Omidi M J,Heydaryan F,et al. Oversampled legendre basis expansion model for doubly-selective channels[C]//Proc of the19th Iranian Conference on Electrical Engineering. Piscataway,NJ:IEEE Press,2011:1-5.
[6] Zuo Huiling,Song Hengguo,Yuan Tianpeng,et al. Channel modeling and estimation in high-speed mobile environment[C]//Proc of the83rd IEEE Vehicular Technology Conference. Piscataway,NJ:IEEE Press,2016:1-5.
[7] Bi Yuming,Zhang Jianhua,Zeng Ming,et al. Channel modeling and estimation for OFDM systems in high-speed trains scenarios[C]//Proc of the 83rd IEEE Vehicular Technology Conference. Piscataway,NJ:IEEE Press,2016:1-6.
[8] Aboutorab N,Hardjawana W,Vucetic B. A new iterative Doppler-assisted channel estimation joint with parallel ICI cancellation for highmobility MIMO-OFDM systems[J]. IEEE Trans on Vehicular Technology,2012,61(4):1577-1589.
[9] Liao Jialing,Qiao Gang,Ma Xuefei. A novel parallel interference cancellation scheme for OFDM in time-varying underwater acoustic channels[C]//Proc of International Conference on Mechatronic Sciences,Electric Engineering and Computer. Piscataway,NJ:IEEE Press,2013:3692-3696.
[10]Liu Chun Hao,Chuang Gene C H. Joint ICI cancellation and channel estimation with real-time channel adaptation for high-mobility OFDM systems[C]//Proc of GLOBECOM Workshops. Piscataway,NJ:IEEE Press,2011:1376-1381.
[11]Nissel R,Rupp M. Doubly-selective MMSE channel estimation and ICI mitigation for OFDM systems[C]//Proc of IEEE International Conference on Communications. Piscataway,NJ:IEEE Press,2015:4692-4697.
[12] Tang Z,Cannizzaro R C,Leus G,et al. Pilot-assisted time-varying channel estimation for OFDM systems[J]. IEEE Trans on Signal Processing,2007,55(5):2226-2238.
[13] Guo Qilin,Wu Muqing,Zhang Qinjuan,et al. Iterative decomposed OFDM channel estimation algorithm over highly mobile channels[J].Wireless Personal Communications,2013,71(2):1137-1158.
[14] Tomasin S,Gorokhov A,Yang Haibing,et al. Iterative interference cancellation and channel estimation for mobile OFDM[J]. IEEE Trans on Wireless Communications,2005,4(1):238-245.
[15]Zemen T,Mecklenbrauker C F. Time-variant channel estimation using discrete prolate spheroidal sequences[J]. IEEE Trans on Signal Processing,2005,53(9):3597-3607.
[16]enol H. Joint channel estimation and symbol detection for OFDM systems in rapidly time-varying sparse multipath channels[J]. Wireless Personal Communications,2015,82(3):1161-1178.
[17]Teo K A D,Ohno S. Optimal MMSE finite parameter model for doublyselective channels[C]//Proc of IEEE Global Telecommunications Conference. Piscataway,NJ:IEEE Press,2005.
[18]尼俊红,刘泽民.基于MMSE准则的改进型并行迭代ICI消除算法[J].电路与系统学报,2011,16(1):74-78.(Ni Junhong,Liu Zeming. Improved parallel iterative ICI cancellation algorithm based on MMSE criterion[J]. Journal of Circuits and Systems,2011,16(1):74-78.)
[19]Sheng Zhichao,Fang Yong,Wang Chen. A BEM method of channel estimation for OFDM systems in high-speed train environment[C]//Proc of International Workshop on High Mobility Wireless Communications. Piscataway,NJ:IEEE Press,2013:6-9.