Efficient Blind MAI Suppression in DS/CDMA Systems by Embedded Constraint Parallel Projection Techniques
Efficient Blind MAI Suppression in DS/CDMA Systems by Embedded Constraint Parallel Projection Techniques
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DOI：
10.1093/ietfec/e88-a.8.2062
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发表时间：
2005-08
期刊：
影响因子：
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通讯作者：
M. Yukawa;R. Cavalcante;I. Yamada
中科院分区：
文献类型：
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作者：
M. Yukawa;R. Cavalcante;I. Yamada
本文提出了两种新的盲集理论自适应滤波算法来抑制DS/CDMA系统中的“多址干扰”。我们自然地将多址干扰抑制问题描述为在期望用户签名定义的线性约束下代价函数序列的渐近最小化。该算法将约束嵌入到更新方向，从而使自适应滤波器在不脱离约束集的情况下向最优滤波器移动。此外，使用并行处理器，所提出的算法在线性计算复杂度下获得了优异的性能。几何解释阐明了所提出的方法相对于现有方法的优势。仿真结果表明，与其他盲方法相比，所提算法具有更快的收敛速度和更好的误码率性能；(2)比非盲NLMS算法有更快的收敛速度(实际上，其收敛速度与非盲RLS算法相当)。
This paper presents two novel blind set-theoretic adaptive filtering algorithms for suppressing "Multiple Access Interference (MAI)," which is one of the central burdens in DS/CDMA systems. We naturally formulate the problem of MAI suppression as an asymptotic minimization of a sequence of cost functions under some linear constraint defined by the desired user's signature. The proposed algorithms embed the constraint into the direction of update, and thus the adaptive filter moves toward the optimal filter without stepping away from the constraint set. In addition, using parallel processors, the proposed algorithms attain excellent performance with linear computational complexity. Geometric interpretation clarifies an advantage of the proposed methods over existing methods. Simulation results demonstrate that the proposed algorithms achieve (i) much higher speed of convergence with rather better bit error rate performance than other blind methods and (ii) much higher speed of convergence than the non-blind NLMS algorithm (indeed, the speed of convergence of the proposed algorithms is comparable to the non-blind RLS algorithm).