Vlsi implementation of cascaded integrator comb filters for. Cascaded integrator comb cic digital filters are computationally efficient implementations of narrowband lowpass filters and are often embedded in hardware implementations of decimation and. Cascaded integrator comb filters digital filter design toolkit. The cascaded integrator comb filters cic find many applications in recent electronic. Cascaded integrator comb cic digital filters are computationally efficient implementations of narrowband lowpass filters and are often embedded in hardware implementations of decimation and interpolation in modern communications.
Using cic filters can cut costs, improve reliability, and help performance. The compensated cic filter response is much flatter in the passband region and the stopband suppression is around 100 db. Decimate signal using cascaded integratorcomb cic filter. Nov 01, 2010 s topselling dsp book for seven straight yearsnow fully updated. Cascaded integrator comb cic filters are one of the most economical multirate filters widely used as decimators in digital receivers.
The cic decimation filter structure consists of n sections of cascaded integrators, followed by a rate change by a factor of r, followed by n sections of cascaded comb filters. Understanding the phasing method of single sideband modulation. Therefore, cic filters are more efficient than conventional fir filters, especially in fixedpoint applications. I created an octave script to generate fixed point coefficients for the serial fir filter i used. Understanding cascaded integratorcomb filters cic and. Lyons, understanding digital signal processing, 3rd edition.
In the classic paper, an economical class of digital filters for decimation and interpolation, hogenauer introduced an important class of digital filters called cascaded integratorcomb, or cic for short also sometimes called hogenauer filters. Example of cascaded integrator comb filter in matlab. Cascaded integratorcomb cic digital filters are computationally efficient implementations of narrowband lowpass filters and are often. Cic filter introduction understanding cascaded integrator comb filters. In this tutorial, matthew donadio provides continued. A beginners guide to cascaded integratorcomb cic filters. Ipug42 cascaded integratorcomb cic filter ip users guide. In digital signal processing, a cascaded integratorcomb cic is an optimized class of finite. In the case of a decimating cic, the input signal is fed through one or more cascaded integrators, then a downsampler, followed by one or more comb. Understanding digital signal processing, second edition book.
These filters are used in the signal decimation which has the. This paper presents the vlsi implementation, analysis and design of high speed cic filters which are based on a lowpass filter. Lyons has thoroughly updated and expanded his bestselling first edition, building on the exceptionally readable coverage that has made it a favorite of both students and professionals worldwide. I would like to ask something regarding cics cascaded integrator comb filters or more particular about the frequency response of it. Pdf understanding cascaded integratorcomb filters researchgate. Take n moving average filters in sequence with decimation at the end rearrange all integrators first, and comb filters last, with the decimator in the middle integrator overflows are removed by combs if unsigned math is used and the bit width is at least nlog 2 d. Us7788309b2 interleaved comb and integrator filter. The next step toward understanding cic filters is to consider an equivalent form, the recursive runningsum filter. Implementation of optimized cascaded integrator comb filters for.
But ive faced situations where my fpga design couldnt fit because of the additional resource consumption of the fir filters. The filters work to reduce artifacts such as dot crawl. He is author of the book understanding digital signal processing, editor and contributor to the book streamlining digital signal processing, and has authored numerous articles on dsp. Jul 01, 2007 equivalence of moving average and cic filter. Cascaded integratorcomb cic filter introduction dspguru. Integrator comb cic filters are useful to reduce as well as to increase the data. Mar 26, 2020 this blog discusses the behavior, mathematics, and implementation of cascaded integrator comb filters. Cicdecimator system object decimates an input signal using a cascaded integratorcomb cic decimation filter. Lyons, understanding digital signal processing pearson. In digital signal processing3, a cascaded integratorcomb cic is an optimized class. A cascaded integrator comb cic filter is a special class of linear phase, finite impulse response fir filter. The recursive comb filters or cascaded integrator comb filter cic are commonly used as decimators for the sigma delta modulators. Performance analysis and behaviour of cascaded integrator. In digital signal processing, a cascaded integratorcomb cic is an optimized class of finite impulse response fir filter combined with an interpolator or decimator a cic filter consists of one or more integrator and comb filter pairs.
Based on above explanation, it is good enough motivation to use oversampling. Understanding digital signal processing, 3rd edition informit. Cascaded integratorcomb cic digital filters are computationally efficient implementations of. Pdf understanding cascaded integrator comb filters semantic. These interleaved structures enable the systems to obtain output data rates that exceed the highest operation rates of the system components. A implementation of a cascaded integrator comb filter for the cortex m4, designed to have an api similar to cmsisdsp. Cascaded integratorcomb cic digital filters are computationally efficient implementations of narrowband lowpass filters and are often embedded in hardware. Filter system embodiments are provided for realizing interpolation and decimation processes with interleaved filter structures. Cascaded integratorcomb cic digital filters are computationally efficient implementations of narrowband lowpass filters and are often embedded in hardware implementations of decimation and interpolation in modern communications. Cascaded integrator comb cic digital filters are computationallyefficient implementations of narrowband lowpass filters, and are often embedded in hardware implementations of decimation, interpolation, and deltasigma converter filtering.
Richard lyons has thoroughly updated and expanded his bestselling second edition, building on the exceptionally readable coverage that has made it a favorite of both professionals and students worldwide. Understanding digital signal processing, second edition is simply the best way for students to master dsp technology. Assuming that i have as input iq samples from a signal genera. Its frequency response may be tuned by selecting the appropriate number of cascaded integrator and comb filter pairs. After cascading the cic filter and the compensation fir filter, i got the following compensated cic filter response.
Hogenauer devised a flexible, multiplier free filter suitable for hardware implementation, that can also handle arbitrary and large rate changes. Understanding digital signal processing, third edition is quite simply the best resource for engineers and other technical professionals who want to master and apply todays latest dsp techniques. Sample rate conversion from understanding digital signal processing. For understanding the cascaded integrator comb cic filter, firstly let us understand the moving average filter, which is accumulation latest samples of an input sequence. Cascaded integratorcomb cic digital filters are computationally efficient implementations of narrowband lowpass filters and are often embedded in hardware implementations of decimation and. The project presents the design of cascadedintegratedcomb filter for the pulseshaping the digital data for. Cascaded integrator comb cic digital filters are computationally efficient implementations of narrowband lowpass filters and are often embedded in hardware implementations of decimation and interpolation in modern communications systems. If you understand the timedomain behavior of a moving averager, then you now understand the timedomain behavior of the cic filter in figure 3.
Understanding digital signal processing 2nd edition. Cic filters were introduced to the signalprocessing community by eugene hogenauer over two decades ago. Cascaded integratorcomb cic digital filters are computationally efficient implementations of narrowband lowpass filters and are often embedded in hardware implementations of decimation and interpolation in modern communications systems. These are known as cascaded integratorcomb filters, or cic filters for short. A cic filter consists of an equal number of stages of ideal integrator followed by comb filters. These filters are used as decimation or interpolation filters and can be effi. Pdf this paper provides several tricks to reduce the complexity and enhance the usefulness of cascaded integratorcomb cic filters. The cascaded integrater comb filter is an efficient way of implementing lowpass filters and is particularly useful for sampling rate conversion using decimation or interpolation. Cic filters were introduced to the signalprocessing community, by eugene hogenauer, more. Let me briefly share my understanding on the cascaded integrator comb cic filter, thanks to the nice article. The transfer functions of both approaches are relevant since it shows that both are equal to each other. To summarize, a cic decimator would have n cascaded integrator stages clocked at.
Cascaded integrator comb cic filters the cascaded integrator comb cic filter is a class of linear filters achieve sampling rate decrease decimation and sampling rate increase interpolation without using multipliers in the filters. Design of five stage cic decimation filter for signal. Cascaded integratorcomb cic filters, commonly used for antialiasing during interpolation and decimation operations that change the sample rate of a discretetime system. An interesting fourier transform 1f noise steve smith. Cascaded integrator comb cic filters the cascaded integratorcomb cic filter is a class of linear filters achieve sampling rate decrease decimation and sampling rate increase interpolation without using multipliers in the filters.
This article discusses the behavior, mathematics, and implementation of cascaded integratorcomb filters. Sep 07, 2015 one of the amazing properties of cic filters is that each integrator stage is allowed to overflow, but the resulting output of the filter doesnt overflow if the filter is designed using 2s complement arithmetic and the filter bit width is wide enough to accomodate the maximum value at the output. It combines the cascaded integratorcomb cic multirate filter. An economical class of digital filters for decimation and interpolation. Signal processing techniques for software radio behrouz farhangboroujeny department of electrical and computer engineering university of utah c 2007, behrouz farhangboroujeny, ece department, university of utah. These are known as cascaded integrator comb filters, or cic filters for short.
Design of five stage cic decimation filter 353 where m denoted as a decimation factor. Pdf the previously obscure cic filter is now vital to many highvolume wireless communications tasks and equipment. Cascaded integrator comb cic filter teymourzadeh, rozita on. At this point, other options need to be considered and cascaded integratorcomb filters are a good one. Hogenauer devised a flexible, multiplierfree filter suitable for. Cic filters do not require multipliers and use a limited amount of storage. Description understanding digital signal processing, 3e is simply the best practitioners resource for mastering dsp technology. Lyons is a consulting systems engineer and lecturer with besser associates in mountain view, california. The two basic building blocks of a cic filter are an integrator and a comb. Jun 16, 2019 application of filter sharpening to cascaded integratorcomb decimation filters pdf a new architecture for the implementation of highorder decimation filters is described.
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