A computationally efficient soft-output detector with lattice-reduction (LR) for the multiple-input multiple-output (MIMO) systems is proposed. In the proposed scheme, the sorted QR de- composition is applied on t...A computationally efficient soft-output detector with lattice-reduction (LR) for the multiple-input multiple-output (MIMO) systems is proposed. In the proposed scheme, the sorted QR de- composition is applied on the lattice-reduced equivalent channel to obtain the tree structure. With the aid of the boundary control, the stack algorithm searches a small part of the whole search tree to generate a handful of candidate lists in the reduced lattice. The proposed soft-output algorithm achieves near-optimal perfor- mance in a coded MIMO system and the associated computational complexity is substantially lower than that of previously proposed methods.展开更多
为了降低Turbo均衡中均衡器的复杂度,该文提出了符号方差反馈均衡算法(SVFE)。该算法是对精确的线性最小均方误差估计值(LMMSE)进行Taylor展开得到的。在该算法中,先利用时不变均衡器得到初步符号估计值,再根据先验符号方差对估计值加权...为了降低Turbo均衡中均衡器的复杂度,该文提出了符号方差反馈均衡算法(SVFE)。该算法是对精确的线性最小均方误差估计值(LMMSE)进行Taylor展开得到的。在该算法中,先利用时不变均衡器得到初步符号估计值,再根据先验符号方差对估计值加权,最后进行时不变滤波得到更佳的符号估计值。由于用到了时变的先验符号方差信息,其性能更接近精确的LMMSE均衡器。将所提算法用于Proakis C信道下的Turbo均衡处理,和时不变均衡算法进行仿真对比,所提算法将信噪比损失从0.83 d B降到了0.17 d B,并且仍可通过快速傅里叶变换降低为对数复杂度。展开更多
针对长期演进技术(LTE)下行多输入多输出正交频分多址链路(MIMO-OFDM)中的天线间干扰和多径干扰的问题,提出一种低复杂度的基于预编码矩阵的迭代均衡算法。该算法通过预编码矩阵将发射信号扩展到所有子载波上,降低由天线引起的部分...针对长期演进技术(LTE)下行多输入多输出正交频分多址链路(MIMO-OFDM)中的天线间干扰和多径干扰的问题,提出一种低复杂度的基于预编码矩阵的迭代均衡算法。该算法通过预编码矩阵将发射信号扩展到所有子载波上,降低由天线引起的部分子载波干扰。在接收端,利用最小均方误差排序QR分解(MMSE-SQRD)软输入软输出干扰消除均衡算法,从而避免传统基于MMSE并行软干扰消除均衡算法中矩阵求逆运算,进而降低了算法复杂度。在接收端,同时通过预编码对重建信号中误差进行扩展,进而缓解在迭代干扰消除过程中的误差传播。研究结果表明:在2发2收场景下,当误码率为10-3时,本文算法经过5次迭代后信噪比相比于传统MMSE-SQRD的迭代算法提高4.4~5.0 d B。展开更多
文摘A computationally efficient soft-output detector with lattice-reduction (LR) for the multiple-input multiple-output (MIMO) systems is proposed. In the proposed scheme, the sorted QR de- composition is applied on the lattice-reduced equivalent channel to obtain the tree structure. With the aid of the boundary control, the stack algorithm searches a small part of the whole search tree to generate a handful of candidate lists in the reduced lattice. The proposed soft-output algorithm achieves near-optimal perfor- mance in a coded MIMO system and the associated computational complexity is substantially lower than that of previously proposed methods.
文摘为了降低Turbo均衡中均衡器的复杂度,该文提出了符号方差反馈均衡算法(SVFE)。该算法是对精确的线性最小均方误差估计值(LMMSE)进行Taylor展开得到的。在该算法中,先利用时不变均衡器得到初步符号估计值,再根据先验符号方差对估计值加权,最后进行时不变滤波得到更佳的符号估计值。由于用到了时变的先验符号方差信息,其性能更接近精确的LMMSE均衡器。将所提算法用于Proakis C信道下的Turbo均衡处理,和时不变均衡算法进行仿真对比,所提算法将信噪比损失从0.83 d B降到了0.17 d B,并且仍可通过快速傅里叶变换降低为对数复杂度。
文摘针对长期演进技术(LTE)下行多输入多输出正交频分多址链路(MIMO-OFDM)中的天线间干扰和多径干扰的问题,提出一种低复杂度的基于预编码矩阵的迭代均衡算法。该算法通过预编码矩阵将发射信号扩展到所有子载波上,降低由天线引起的部分子载波干扰。在接收端,利用最小均方误差排序QR分解(MMSE-SQRD)软输入软输出干扰消除均衡算法,从而避免传统基于MMSE并行软干扰消除均衡算法中矩阵求逆运算,进而降低了算法复杂度。在接收端,同时通过预编码对重建信号中误差进行扩展,进而缓解在迭代干扰消除过程中的误差传播。研究结果表明:在2发2收场景下,当误码率为10-3时,本文算法经过5次迭代后信噪比相比于传统MMSE-SQRD的迭代算法提高4.4~5.0 d B。