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数字滤波器是数字信号处理的关键组件之一,主要由加(减)法器、乘法器、延迟模块等部分组成。按单位脉冲响应长度,数字滤波器可分为无限脉冲响应滤波器和有限脉冲响应滤波器两类,分别称为IIR滤波器和FIR滤波器。本文以设计二阶无限脉冲响应滤波器IIR滤波器为例,选用ALTERA公司的FLEXl0KA系列FPGA,表述从单元设计、逻辑综合、布局布线到仿真验征的设计流程。 相似文献
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为了避免传统的经验方法设计增益均衡滤波器(GEF)的主观性和不确定性,将电子学格型有限冲激响应(FIR)数字滤波的概念和算法移植到光学格型滤波器,提出一种基于掺Er光纤放大器(EDFA)自发增益(ASE)谱的频率采样设计法和光格型GEF的设计方案。该滤波器由数个各种分光比的波导耦合器经由具有单位时延差的光波导级连构成。分析了根据目标传递函数求解光格型阵列参数的算法,进而针对实际的ASE谱设计了40阶的GEF,在1527~1564nm波段内的增益平坦波动小于±0.4dB,并具有线性相频响应特性和互易性。 相似文献
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无限脉冲响应(IIR)数字滤波器在很多领域中有着广阔的应用。本文用Butterworth法、切比雪夫1法法、切比雪夫2法通过MATLAB仿真软件对几种给定性能的IIR数字滤波器进行了仿真设计,并用基于MOTOROLA公司的M68HC11单片机进行了硬件设计实现,表明数字滤波器具有灵活、方便、功能强的特点。 相似文献
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从设计原理和软件实现两个方面对软件无线电中的FIR(有限长单位脉冲响应)内插成型滤波器的设计与实现的方法进行了分析:以降低滤波运算量,提高性能,减少数据缓存量与输出延迟为目标,采用基于子滤波器时分处理的多相滤波器的设计方法。在此基础上,运用切比雪夫逼近法来计算内插滤波器的频响,并针对具体的数字无线电台的内插滤波器的几种实现方案进行了比较。 相似文献
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Yanfei Cao Kai Wang Wenjiang Pei Yujie Liu Yifeng Zhang 《Circuits, Systems, and Signal Processing》2011,30(5):963-985
Expensive multiplication operations can be replaced by simpler additions and hardwired shifters so as to reduce power consumption
and area size, if the coefficients of a digital filter are signed power-of-two (SPT). As a consequence, FIR digital filters
with SPT coefficients have been widely studied in the last three decades. However, most approaches for the design of FIR filters
with SPT coefficients focus on filters with length less than 100. These approaches are not suitable for the design of high-order
filters because they require excessive computation time. In this paper, an approach for the design of high-order filters with
SPT coefficients is proposed. It is a two-step approach. Firstly, the design of an extrapolated impulse response (EIR) filter
is formulated as a standard second-order cone programming (SOCP) problem with an additional coefficient sensitivity constraint
for optimizing its finite word-length effect. Secondly, the obtained continuous coefficients are quantized into SPT coefficients
by recasting the filter-design problem into a weighted least squares (WLS) sequential quadratic programming relaxation (SQPR)
problem. To further reduce implementation complexity, a graph-based common subexpression elimination (CSE) algorithm is utilized
to extract common subexpressions between SPT coefficients. Simulation results show that the proposed method can effectively
and efficiently design high-order SPT filters, including Hilbert transformers and half-band filters with SPT coefficients.
Experiment results indicate that 0.81N∼0.29N adders are required for 18-bit N-order FIR filters (N=335∼3261) to meet the given magnitude response specifications. 相似文献
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本文提出了全相位数据空间的概念,并基于DFT/IDFT滤波导出了一种新型的零相位滤波器——全相位DFT(APDFT)数字滤波器.本文给出了它的脉冲响应与相应的DFT滤波响应向量之间的正、反变换公式,证明了这种滤波器的一些重要性质.APDFT方法兼有窗函数法和频率采样法的优点,是一种设计FIR滤波器的新方法.理论分析和模拟实验证实,其总体性能优于传统方法.APDFT数字滤波器除可用通常的卷积结构实现外,也可用一种直接频域网络实现.本文给出了这种网络结构及其简化算法.这种网络具有实时自设计功能.它可以构成时变系统用于滤波器传递函数实时可变的场合,可以方便地集成为一个长度和频响均可编程的通用零相位数字滤波器,而且还可用于实现严格互补子带滤波. 相似文献
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In this paper, we propose a method for designing a class of M‐channel, causal, stable, perfect reconstruction, infinite impulse response (IIR), and parallel uniform discrete Fourier transform (DFT) filter banks. It is based on a previously proposed structure by Martinez et al. [1] for IIR digital filter design for sampling rate reduction. The proposed filter bank has a modular structure and is therefore very well suited for VLSI implementation. Moreover, the current structure is more efficient in terms of computational complexity than the most general IIR DFT filter bank, and this results in a reduced computational complexity by more than 50% in both the critically sampled and oversampled cases. In the polyphase oversampled DFT filter bank case, we get flexible stop‐band attenuation, which is also taken care of in the proposed algorithm. 相似文献
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详细讨论了4型线性相位滤波器的幅频特性与正弦基函数神经网络算法的关系,分析了神经网络系统的稳定条件,给出了FIR滤波器优化设计实例。根据4型FIR滤波器的幅频响应特性,构造出一个相应的神经网络模型,并建立了FIR线性相位数字滤波器的神经网络算法。该算法通过训练神经网络权值,使设计的数字滤波器与希望得到的FIR线性相位滤波器的幅频响应之间的误差平方和最小化,从而获得FIR线性相位数字滤波器的脉冲响应。计算机仿真表明了该算法的有效性和优异性能。 相似文献
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自积分式磁场传感器用于脉冲场测量时,普遍存在低频失真问题,本文提出一种数字滤波的方案对传感器的低频特性进行补偿。滤波器采用无限冲激响应滤波器的形式,并以系统辨识的方法直接在时域进行设计,应用结果表明,该滤波器能有效地修复失真波形,使传感器的响应特性得到显著改善。 相似文献
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This paper presents architecture design techniques for implementing both single-rate and multirate high-speed finite impulse response (FIR) digital filters, with emphasis on the multirate multistage interpolated FIR (IFIR) digital filters. Well-known techniques to achieve high-speed and low-power applications for the single-rate digital FIR architecture are summarized, followed by the introduction of variable filter order selection, optimal filter decomposition, memory-saving and mirror symmetric filter pairs techniques which offer further gains in both performance and complexity reduction for the multirate multistage digital FIR architecture. A filter design example with TSMC 0.25?µm standard cell for 64-QAM baseband demodulator shows that the area is reduced by 39% for low-complexity application. Moreover, for high-speed application, the chip can operate at 714?MHz. Finally, a designed decimator which is used in the CDMA cellular shows that the area is reduced by 70% as compared with conventional approach. 相似文献
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Hui Zhao Juebang Yu 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2006,53(2):157-160
In this paper, a simple and efficient approach for designing one-dimensional variable fractional delay finite impulse response digital filters is proposed. Two matrix equations, based respectively on the weighted least-squares function of the optimum fixed fractional delay filter and the filter coefficient polynomial fitting, are formulated in tandem to form the design algorithm, which only has the computation complexity comparable with that of designing fixed finite impulse response digital filters. A design example is also given to justify the effectiveness and advantages of the proposed design method. 相似文献
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为了解决多频段数字均衡滤波器处理过程中数据计算量的问题,通过对数字均衡器设计的分析,将数字音频信号进行频域滤波处理,最终设计出一种高效的数字均衡滤波器。通过将数字信号在频域中进行傅里叶变换,提出了一种基于快速傅里叶变换原理的算法,该算法中码位倒置和蝶形运算方法的处理与通常的快速傅里叶变换相比,更有效地减少了数据的运算量,减少了数据处理的时间。结果表明,使用该种算法设计的数字均衡滤波器与传统的时域滤波方法相比,具有很好的实时处理效果。 相似文献
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Digital filtering is the process of spectrum shaping using digital components as the basic elements. Increasing speed and decreasing size and cost of digital components make it likely that digital filtering, already used extensively in the computer simulation of analog filters, will perform, in real-time devices, the functions which are now performed almost exclusively by analog components. In this paper, using the z-transform calculus, several digital filter design techniques are reviewed, and new ones are presented. One technique can be used to design a digital filter whose impulse response is like that of a given analog filter; other techniques are suitable for the design of a digital filter meeting frequency response criteria. Another technique yields digital filters with linear phase, specified frequency response, and controlled impulse response duration. The effect of digital arithmetic on the behavior of digital filters is also considered. 相似文献