共查询到17条相似文献,搜索用时 156 毫秒
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针对采样率变换系统中CIC抽取滤波器存在通带失真较大和阻带衰减较小的问题,提出一种高性能CIC抽取滤波器的设计方法,该方法采用补偿滤波器技术和非递归并行结构.仿真结果表明,通带失真与阻带衰减特性明显优于传统的CIC,CIC-Cosine,ISOP-CIC等滤波器.因此,适用于对幅频特性要求较高的采样率变换系统. 相似文献
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用于软件无线电中的整数倍采样率转换技术 总被引:4,自引:0,他引:4
主要讨论了用于软件无线电中的整数倍采样率转换技术。首先讨论了进行整数倍采样率转换的必要性。然后讨论了用于设计抽取器的关键参数,实现结构及其相应滤波器的设计。文章最后讨论了用于频谱成形和通带衰减补偿的FIR滤波器的必要性和设计方法。 相似文献
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为了有效提高数字信号处理的实时性,经常要进行整倍数采样率的转换。简要介绍多抽样率信号处理理论及内插原理,在此基础上介绍了3种高效滤波器的特点,探讨了多相滤波网络结构的等效变换和多相滤波的设计理论。重点推导并给出了基于多相分解的内插多相滤波器的工作原理和结构以及实际工程应用,这种滤波器结构算法简单,并且最大限度地减少资源消耗、降低系统复杂度,提高运算速度,对工程实现具有较大的实用价值。 相似文献
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The introduction of nonlinear optimization techniques to the design of a frequency-response masking (FRM) filter has changed
the way in which an FRM filter is synthesized. It allows all subfilters in an FRM structure to be optimized jointly, resulting
in further savings in the number of arithmetic operations. Under the joint optimization, a new set of design equations is
necessary, not only for a more computationally efficient filter, but also for the simplification of the design process and
the reduction of the design time. In this paper, we present a set of design equations that estimates the filter lengths and
optimum interpolation factor in an FRM filter under joint optimization. It is shown, by means of examples, that the proposed
design equations lead to a better estimation of the optimum interpolation factor compared with existing design equations. 相似文献
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Design of Computationally Efficient Sharp FIR Filter Utilizing Modified Multistage FRM Technique for Wireless Communications Systems 下载免费PDF全文
Modern wireless communications gadgets demand multi-standard communications facilities with least overlap between different input radio channels. A sharp digital filter of extremely narrow transition-width with lower stop band ripples offers alias-free switching among the preferred frequency bands. A computationally competent low pass filter (LPF) structure based on the multistage frequency response masking (FRM) approach is proposed for the design of sharp finite impulse response (FIR) filters which are suitable for wireless communications applications. In comparison of basic FRM with other existing multistage FRM structures, the proposed structure has a narrow transition bandwidth and higher stop band attenuation with significant reduction in terms of the number of computational steps. A design example is incorporated to demonstrate the efficiency of the proposed approach. Simulation results establish the improvement of the proposed scheme over other recently published design strategies. 相似文献
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In the frequency-response masking (FRM) approach, the complexity of two
masking filters is heavily dependent on the interpolation factor and the cutoff frequencies
of the bandedge shaping filter. In this paper, we propose a novel structure that decouples
the masking filters from the bandedge shaping filter. The design equations together with the
design procedures are presented. With the introduction of an additional decoupling stage,
the complexity of the overall filter can be greatly reduced. Our example shows that more
than 40% savings in the numbers of multipliers and adders can be achieved compared with
the original FRM approach. 相似文献
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Yong Ching Lim Ya Jun Yu Saramaki T. 《IEEE transactions on circuits and systems. I, Regular papers》2005,52(11):2444-2453
Hilbert transformers and half-band filters are two very important special classes of finite-impulse response filters often used in signal processing applications. Furthermore, there exists a very close relationship between these two special classes of filters in such a way that a half-band filter can be derived from a Hilbert transformer in a straightforward manner and vice versa. It has been shown that these two classes of filters may be synthesized using the frequency-response masking (FRM) technique resulting in very efficient implementation when the filters are very sharp. While filters synthesized using the FRM technique has been characterized for the general low-pass case, Hilbert transformers and half-band filters synthesized using the FRM technique have not been characterized. The characterization of the two classes of filter is a focus of this paper. In this paper, we re-develop the FRM structure for the synthesis of Hilbert transformer from a new perspective. This new approach uses a frequency response correction term produced by masking the frequency response of a sparse coefficient filter, whose frequency response is periodic, to sharpen the bandedge of a low-order Hilbert transformer. Optimum masking levels and coefficient sparseness for the Hilbert transformers are derived; corresponding quantities for the half-band filters are obtained via the close relationship between these two classes of filters. 相似文献
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Diniz P.S.R. de Barcellos L.C.R. Netto S.L. 《Signal Processing, IEEE Transactions on》2004,52(5):1278-1288
Due to the growing importance of multichannel modulation, there has been great interest in the design of high-performance transmultiplex systems. In this paper, a new cosine-modulated transmultiplex structure is proposed based on a prototype filter designed with the frequency-response masking (FRM) approach. This new structure leads to substantial reduction in the computational complexity (number of multiplications per output sample) of the prototype filters having sharp transition band and equivalently small roll-off values. The relation between the interpolation factor used in the FRM prototype filter and the decimation factor in the subbands leads to distinct structures. Examples included indicate that the reduction in computational complexity can be higher than 50% of the current state-of-art designs, whereas the reduction on the number of distinct coefficients of the prototype filter can be reduced even further (over 75%). As a result, the proposed approach allows the design of very selective subfilters for transmultiplexes with a very large number of subchannels. 相似文献
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Lee W.R. Caccetta L. Teo K.L. Rehbock V. 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2006,53(5):379-383
This paper presents an application of the weighted least squares (WLS) method to the design of sharp linear phase finite-impulse response (FIR) digital filters synthesized using a modified frequency-response masking (FRM) structure. In our approach, the original minimax design problem is converted into a WLS problem. The WLS problem is highly nonlinear with respect to the coefficients of the filter. However, it can be decomposed into four linear least squares (LS) problems, each of which can be solved analytically. The design problem is then solved iteratively by using an alternating variable approach. The effectiveness of the method is demonstrated through solving a low-pass linear phase sharp FIR digital filter example. 相似文献
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A new method to reduce the number of arithmetic operations in a sharp FIR filter
synthesized by the frequency-response masking (FRM) technique is presented. The success
of the proposed method is based on a modified FRM approach where the subfilters in
the FRM approach are implemented by using recently introduced prefilter-equalizer based
filters. It is shown, by means of examples, that the proposed method yields considerable
savings in the numbers of multipliers and adders compared to the original single-stage
FRM approach. 相似文献