共查询到20条相似文献,搜索用时 15 毫秒
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本文对基于子带分解的自适应滤波做了研究,给出子带分解下的包含子带间滤波的最优维纳解和LMS算法,并分析了其收敛性能和计算复杂度,与传统的LMS算法相比,基于子带分解的自适应滤波具有更好的性能,计算机模拟结果也体现了这一点。 相似文献
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To overcome the limitations of a conventional fullband adaptive filtering, various subband adaptive filtering (SAF) structures have been proposed. Properly designed, an SAF will converge faster at a lower computational cost than a fullband structure. However, its design should consider the following two facts: the interband aliasing introduced by the downsampling process degrades its performance, and the filter bank in the SAF introduces additional computational overhead and system delay. In this paper, to fully exploit the benefits of using an SAF, an almost alias-free SAF structure with critical sampling is proposed. The interband alising is removed from the subband signal by isolating the aliasing using a bandwidth-increased analysis filter. Computer simulations show that the proposed structure converges faster than both an equivalent fullband structure at lower computational complexity and recently proposed SAF structures for a colored input. 相似文献
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Nonuniform Subband Adaptive Filtering With Critical Sampling 总被引:2,自引:0,他引:2
Adaptive subband structures have been proposed with the objective of increasing the convergence speed and/or reducing the computational complexity of conventional adaptive algorithms, mainly for applications that require a large number of adaptive coefficients. In this paper, we present a nonuniform subband structure with critical sampling, which is capable of modeling an arbitrary finite-impulse response (FIR) system with reduced aliasing. A least-mean-square (LMS)-type adaptation algorithm with normalized step sizes, which works at the lowest downsampling rate and minimizes the average of the subband squared errors, is derived for the proposed structure. A convergence analysis of the adaptation algorithm is presented, from which its convergence rate and steady-state mean-square error can be estimated. 相似文献
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Yung-Yi Lin Ran-Zan Wang 《IEEE signal processing letters》2010,17(3):245-248
In 2007, Wang and Shyu proposed a scalable secret image sharing scheme in which three sharing styles, namely the multisecret, priority, and progressive modes, are designed to encode an image with diverse revealing effects. Their scheme is a (2, n ) sharing method where each generated shadow image is half size of the original image. This letter proposes a general (t,n), 2 ? t ? n, scalable secret image sharing scheme with the same revealing effects. Notably, the size of each generated shadow image is only (2n-t)/n 2 times of the original image. The smaller size of the generated shadow images makes their transmission and storage more efficient. 相似文献
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《Signal Processing, IEEE Transactions on》2008,56(12):5840-5850
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由于广播节目受众广,影响力大,其播控要求高,对错播、插播、漏播等异常播出情况容忍度低。针对广播节目播出实时监测问题,本文提出了一种快速的广播音频信号相似性检测方法。该方法计算Pearson相关系数来判别两广播音频信号是否相似。然后,为了抵消编解码器、收发设备及传输信道的影响,应用自适应Volterra滤波器来处理信号。最后,用子带分解技术将全频带信号分解为子带信号,并仅对功率最高的子带进行分析预处理,以降低计算量。实验结果表明,在考虑了真实的传输影响后,通过不同条件的比较,该方法具有良好的检测准确度,且计算量较小,可以满足实时处理的要求。 相似文献
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自适应滤波器在系统辨识、回声消除、信道均衡等领域获得了广泛应用.符号子带自适应滤波器(Sign Subband Adaptive Filter,SSAF)具有较强的抗脉冲干扰能力,但当输入信号受到噪声干扰时,其对未知系统系数向量的估计会产生偏差.为了解决上述问题,本文基于无偏估计准则,提出了一种偏差补偿符号子带自适应滤波器(Bias-Compensated Sign Subband Adaptive Filter,BC-SSAF).为了解决定步长自适应滤波器需要在收敛速度和稳态失调之间进行折中的问题,本文采用随机梯度法来更新正则化参数,提出了变正则化参数偏差补偿符号子带自适应滤波器(Variable Regularization Bias-Compensated Sign Subband Adaptive Filter,VR-BC-SSAF).仿真结果验证了BC-SSAF和VR-BC-SSAF性能的优越性. 相似文献
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Yongtao Wang Hamid Mahmoodi Lih-Yih Chiou Hunsoo Choo Jongsun Park Woopyo Jeong Kaushik Roy 《Journal of Signal Processing Systems》2010,58(2):125-137
Polyphase channelizer is an important component of subband adaptive filtering systems. This paper presents an energy-efficient
hardware architecture and VLSI implementation of polyphase channelizer, integrating algorithmic, architectural and circuit
level design techniques. At algorithm level, low complexity polyphase channelizer architecture is derived using multirate
signal processing approach. To reduce the computational complexity in polyphase filters, computation sharing differential
coefficient (CSDC) method is effectively used as an architectural level technique. The main idea of CSDC is to combine the
strength of augmented differential coefficient method and subexpression sharing. Efficient circuit-level techniques: low power
commutator implementation, dual-VDD scheme and novel level-converting flip-flop (LCFF), are also used to further reduce the
power dissipation. The proposed polyphase channelizer consumes 352 mW power with throughput of 480 million samples per second
(MSPS). A test chip has been fabricated in 0.18 μm CMOS technology and its functionality is verified. Chip measurement results
show that the dual-VDD implementation achieves a total power saving of 2.7 X. 相似文献
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利用改进的多带结构子带自适应滤波(IMSAF)算法辨识具有稀疏特性的未知系统.代价函数引入加权的l1范数作为附加约束,并结合次梯度分析方法推导出新的更新方程.根据加权矩阵选取的不同,提出了两个li范数约束的IMSAF算法:l1-IMSAF和l1-RIMSAF.仿真结果表明,在未知系统具备稀疏特性的条件下,相较于传统的IMSAF算法,两个新算法的收敛性能具有显著提高. 相似文献
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A new algorithm, which is a variant of the sign algorithm, is proposed for the adaptive adjustment of an FIR digital filter with an aim of improving the original convergence characteristics, yet retaining the advantage of hardware simplicity. Based on a recently proposed theory for the sign algorithm, a practical design method is derived for the new algorithm, and it is shown by computer simulation that the new algorithm in fact performs significantly better than the original algorithm. 相似文献
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一种自适应电子调速器的设计 总被引:2,自引:0,他引:2
文章给出了一种自适应电子调速器的基本结构;论述了调速器的工作原理、电路的设计和软件编程方法。进口电子调速器所用的控制算法只限于传统PID,控制效果不理想。文章给出的电子调速器采用先进的自适应控制算法,优化了电路的设计,提高了控制精度,实际应用情况良好。 相似文献