A new semi-blind adaptive beamforming scheme is proposed for multi-input multi-output （MIMO） induced and spacedivision multiple-access based wireless systems that employ high order phase shift keying signaling. A mi...A new semi-blind adaptive beamforming scheme is proposed for multi-input multi-output （MIMO） induced and spacedivision multiple-access based wireless systems that employ high order phase shift keying signaling. A minimum number of training symbols, very close to the number of receiver antenna elements, are used to provide a rough initial least squares estimate of the beamformer＇s weight vector. A novel cost function combining the constant modulus criterion with decision-directed adaptation is adopted to adapt the beamformer weight vector. This cost function can be approximated as a quadratic form with a closed-form solution, based on which we then derive the recursive least squares （RLS） semi-blind adaptive beamforming algorithm. This semi-blind adaptive beamforming scheme is capable of converging fast to the minimum mean-square-error beamforming solution, as demonstrated in our simulation study. Our proposed semi-blind RLS beamforming algorithm therefore provides an efficient detection scheme for the future generation of MIMO aided mobile communication systems.展开更多
由于长短码直扩码分多址(LSC-DS-CDMA)信号包含了多个用户的长码和短码,已有的直扩码分多址信号的盲伪码估计方法不再适用。为此该文提出一种基于矩阵填充和三阶相关的伪码估计方法。首先从理论上将结构复杂的LSC-DS-CDMA信号构建为多...由于长短码直扩码分多址(LSC-DS-CDMA)信号包含了多个用户的长码和短码,已有的直扩码分多址信号的盲伪码估计方法不再适用。为此该文提出一种基于矩阵填充和三阶相关的伪码估计方法。首先从理论上将结构复杂的LSC-DS-CDMA信号构建为多用户短码扩频的缺失矩阵模型,将复合码矩阵估计建模为盲源信号分离问题;然后将矩阵填充理论应用于复合码矩阵估计,提出基于奇异值阈值算法和快速独立成分分析算法的各用户复合码序列估计方法;最后利用m序列的移位相加性特性,提出延迟三阶相关算法,从各用户复合码序列中估计其包含的长短伪码序列。仿真表明,当信噪比高于-2 d B时,该文算法的长短伪码估计平均误码率低于0.1%。展开更多
文摘A new semi-blind adaptive beamforming scheme is proposed for multi-input multi-output （MIMO） induced and spacedivision multiple-access based wireless systems that employ high order phase shift keying signaling. A minimum number of training symbols, very close to the number of receiver antenna elements, are used to provide a rough initial least squares estimate of the beamformer＇s weight vector. A novel cost function combining the constant modulus criterion with decision-directed adaptation is adopted to adapt the beamformer weight vector. This cost function can be approximated as a quadratic form with a closed-form solution, based on which we then derive the recursive least squares （RLS） semi-blind adaptive beamforming algorithm. This semi-blind adaptive beamforming scheme is capable of converging fast to the minimum mean-square-error beamforming solution, as demonstrated in our simulation study. Our proposed semi-blind RLS beamforming algorithm therefore provides an efficient detection scheme for the future generation of MIMO aided mobile communication systems.
基金Supported by National Natural Science Foundation of P. R. China (69975011, 60172067, 60133020, 60325208), "863" Program (2002AA144060)Funding of China National Education Ministry, Natural Science Foundation of Guangdong Province (013164)
文摘由于长短码直扩码分多址(LSC-DS-CDMA)信号包含了多个用户的长码和短码,已有的直扩码分多址信号的盲伪码估计方法不再适用。为此该文提出一种基于矩阵填充和三阶相关的伪码估计方法。首先从理论上将结构复杂的LSC-DS-CDMA信号构建为多用户短码扩频的缺失矩阵模型,将复合码矩阵估计建模为盲源信号分离问题;然后将矩阵填充理论应用于复合码矩阵估计,提出基于奇异值阈值算法和快速独立成分分析算法的各用户复合码序列估计方法;最后利用m序列的移位相加性特性,提出延迟三阶相关算法,从各用户复合码序列中估计其包含的长短伪码序列。仿真表明,当信噪比高于-2 d B时,该文算法的长短伪码估计平均误码率低于0.1%。
