共查询到18条相似文献,搜索用时 125 毫秒
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本文在分析得出MIMO-OFDM系统中的子空间盲信道估计方法不能用在发射天线数大于接收天线数这种情况下,引出了基于非冗余线性预编码的子空间盲估计算法,分析了预编码矩阵的设计方法.最后通过算法的仿真得出,只要P的取值合适,该算法就会有着很好的估计性能,并且通过分析发现,该算法的计算复杂度较小. 相似文献
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基于信号子空间的改进OFDM系统信道半盲估计 总被引:1,自引:0,他引:1
本文改进了一种基于信号子空间的OFDM系统半盲信道估计算法.该算法利用基于梯度变化的变遗忘因子递归最小二乘算法(GVFF-RLS)计算接收信号的自相关矩阵.通过同时对角化接收信号中的信息信号和噪声信号的全局协方差矩阵,推导出噪声信号子空间,无需对噪声信号的统计特性进行任何先验假定.本算法弥补了原始算法在慢衰落信道下收敛慢以及只限于加性白噪声的不足,实现了色噪声背景下高效半盲信道估计.仿真结果表明本文提出的算法具有良好的性能. 相似文献
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深入分析了基于二阶统计特性的子空间盲信道估计算法,在分析得出MIMO—OFDM系统中的子空间盲信道估计方法不能用在发射天线数大于接收天线数这种情况下,引出了基于非冗余线性预编码的子空间盲估计算法。仿真结果表明,只要尸的取值合适,该算法就会有着很好的估计性能,并且通过分析发现,该算法的计算复杂度较小。 相似文献
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在正交频分复用(OFDM)系统的超分辨时延估计中,针对多重信号分类(MUSIC)算法的特征分解计算复杂度较高的问题,给出一种基于传播算子(PM)的时延估计算法。对OFDM系统进行信道估计,根据信道估计结果计算协方差矩阵,并利用协方差矩阵计算PM,然后根据PM构造出噪声子空间并将其标准正交化,最后利用伪谱函数进行时延估计。仿真结果和复杂度分析表明,在复杂度大幅度下降的条件下,所提算法与MUSIC性能相当,且逼近克拉美罗界。 相似文献
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A new approach to blind and semi-blind channel estimation for space-time block codes (STBCs) is presented. By exploiting the recently proposed generalized space-time block code framework, an STBC system is reduced from multiple-input multiple-output to a single-input multiple-output system. A conventional blind algorithm based on the subspace algorithm is then used to identify the channel impulse responses and achieve equalization. Simulation results demonstrate the performance of the proposed algorithm and a comparable scheme. 相似文献
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We discuss a synchronous direct-sequence code division multiple-access (DS-CDMA) system based on block spreading in the presence of frequency-selective fading. Note that block spreading, which is also known as chip interleaving, refers to a spreading of a data block sequence, which is obtained by dividing a data symbol sequence into consecutive blocks. For such a system, we develop a simple new receiver that completely removes the multiuser interference (MUI) without using any channel information. The MUI-free operation is obtained by the use of a shift-orthogonal set of code sequences on which this receiver is based. Within the framework of the MUI-free receiver, we further present a subspace deterministic blind single-user channel estimation algorithm. As a benchmark for the MUI-free receiver and the corresponding subspace deterministic blind single-user channel estimation algorithm, we consider the linear multiuser equalizer and the corresponding subspace deterministic blind multiuser channel estimation algorithm developed by Liu and Xu (1996) for a standard synchronous DS-CDMA system in the presence of frequency-selective fading. We show that the complexity of the MUI-free receiver using the corresponding subspace deterministic blind single-user channel estimation algorithm is much smaller than the complexity of the linear multiuser equalizer using the corresponding subspace deterministic blind multiuser channel estimation algorithm. We further show that the performance of the MUI-free receiver is comparable with the performance of the linear multiuser equalizer. This is for the case in which the channels are known as well as for the case in which the channels are estimated with the corresponding subspace deterministic blind channel estimation algorithm 相似文献
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多重信号分类(MUSIC)时延估计算法需要多径数估计,且其特征分解和谱峰搜索的计算复杂度较高。针对此问题,给出了一种基于逼近噪声子空间的求根时延估计算法。该算法利用协方差矩阵逆的高次幂逼近噪声子空间与其自身共轭转置的积,并构造多项式等式,以多项式求根的方式避免谱峰搜索,从而降低了计算复杂度。仿真结果表明,在无需多径数估计和复杂度低于MUSIC算法的条件下,所提算法的性能与MUSIC算法的性能相当,并且逼近克拉美罗界。 相似文献