This paper proposes an efficient scheme to track the time variant channel induced by multi-path Rayleigh fading in mobile wireless multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) systems with null sub-carriers. In the proposed method, a blind channel response predictor is designed to cope with the time variant channel. The proposed channel tracking scheme consists of a frequency domain estimation approach that is coupled with a minimum mean square error (MMSE) time domain estimation method, and does not require any matrix inverse calculation during each OFDM symbol. The main attributes of the proposed scheme are its reduced computational complexity and good tracking performance of channel variations. The simulation results show that the proposed method exhibits superior performance than the conventional channel tracking method [Y.G. Li, N. Seshadri, S. Ariyavisitakul, Channel estimation for OFDM systems with transmitter diversity in mobile wireless channels, IEEE J. Sel. Areas Commun. 17 (March 1999) 461-471] in time varying channel environments. At a Doppler frequency of 100 Hz and bit error rates (BER) of 10~(-4), signal-to-noise power ratio (E_b,/N_0) gains of about 2.5 dB are achieved relative to the conventional channel tracking method [Y.G. Li, N. Seshadri, S. Ariyavisitakul, Channel estimation for OFDM systems with transmitter diversity in mobile wireless channels, IEEE J. Sel. Areas Commun. 17 (March 1999) 461-471]. At a Doppler frequency of 200 Hz, the performance difference between the proposed method and conventional one becomes much larger.
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机译:本文提出了一种有效的方案,用于在带有空子载波的移动无线多输入多输出正交频分复用(MIMO-OFDM)系统中跟踪由多径瑞利衰落引起的时变信道。在提出的方法中,盲信道响应预测器被设计为应付时变信道。所提出的信道跟踪方案包括频域估计方法,该方法与最小均方误差(MMSE)时域估计方法相结合,并且在每个OFDM符号期间不需要任何矩阵逆计算。所提出的方案的主要属性是其降低的计算复杂度和信道变化的良好跟踪性能。仿真结果表明,与传统的信道跟踪方法相比,该方法具有更好的性能。 Li,N. Seshadri,S. Ariyavisitakul,《移动无线信道中具有发射机分集的OFDM系统的信道估计》,IEEE J. Sel。地区社区。时变信道环境中,图17(1999年3月)461-471]。在100 Hz的多普勒频率和10〜(-4)的误码率(BER)下,相对于传统的信道跟踪方法,可以获得约2.5 dB的信噪功率比(E_b,/ N_0)[ G Li,N. Seshadri,S. Ariyavisitakul,《移动无线信道中具有发射机分集的OFDM系统的信道估计》,IEEE J. Sel。地区社区。 17(1999年3月)461-471]。在200 Hz的多普勒频率下,提出的方法与常规方法之间的性能差异变得更大。
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