赵海军, 贺春林, 蒲斌. OFDM系统中基于状态空间模型的ICI抑制均衡算法[J]. 云南大学学报(自然科学版), 2016, 38(6): 859-865. doi: 10.7540/j.ynu.20160375
引用本文: 赵海军, 贺春林, 蒲斌. OFDM系统中基于状态空间模型的ICI抑制均衡算法[J]. 云南大学学报(自然科学版), 2016, 38(6): 859-865. doi: 10.7540/j.ynu.20160375
ZHAO Hai-jun, HE Chun-lin, PU Bin. An equalization algorithm based on state space model for ICI inhibition in OFDM system[J]. Journal of Yunnan University: Natural Sciences Edition, 2016, 38(6): 859-865. DOI: 10.7540/j.ynu.20160375
Citation: ZHAO Hai-jun, HE Chun-lin, PU Bin. An equalization algorithm based on state space model for ICI inhibition in OFDM system[J]. Journal of Yunnan University: Natural Sciences Edition, 2016, 38(6): 859-865. DOI: 10.7540/j.ynu.20160375

OFDM系统中基于状态空间模型的ICI抑制均衡算法

An equalization algorithm based on state space model for ICI inhibition in OFDM system

  • 摘要: 为了对具有高多普勒扩展的频率选择性信道采用OFDM时,由于快速时变对子载波正交性的破坏而引入的载波间干扰进行抑制,提出了一种OFDM系统及抑制ICI的均衡算法.具体实现是首先通过对OFDM系统工作原理的分析,得到其ICI的表达式;然后把系统看作一个状态空间模型,在得到接收机端精确的信道状态信息情况下,采用AR-2模型得到信道抽头向量,把每个时刻的状态向量Sn看成是由L个相邻发射符号构成,从而采用卡尔曼滤波器来对接收机端的接收符号进行均衡.仿真结果表明,文章提出的均衡算法不仅在BER性能方面优于目前常用的几种均衡算法,而且还可以降低计算复杂度,同时在发射端采用卷积码,在接收端采用维特比译码器对系统性能也有改善.

     

    Abstract: In order to suppress the inter-carrier interference introduced into the frequency selective channel with high Doppler spread when the OFDM is used due to the orthogonality of subcarriers perturbed by the fast time variation,a OFDM system and equalization algorithm for ICI mitigation is proposed in this paper.The concrete implementation is that the expression of its ICI is obtained firstly through the analysis of the principle of OFDM system.And then the system is regarded as a state space model and the accurate channel state information at the receiver end is obtained.The Auto Regressive process of order-2 model is used to obtain the channel tap vector,and the state vector Sn at each instant is taken to comprise the L consecutive transmitted symbol values,and the Calman filter is used to equalize the received symbols at the receiver.Simulation results show that the proposed equalization algorithm is not only superior to several commonly used equalization algorithms in terms of the BER performance,but also can reduce the computational complexity.At the same time,the performance of the system is improved by using the convolutional coding at the transmitter and Viterbi decoder at the receiver.

     

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