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Polyphase FIR interpolation filter

Hello! Im looking for a simple matlab code that illustrates an interpolation using polyphase implementation. I need this to understand the purpose with the polyphase structure. Maybe anyone knows some sources also? Thanks in advance ...

polyphase filtering

hi.. This is my 1st mail to this group. I am trying to do a polyphase filter bank in dsp and thn get it into FPGA.. this is not for decimation or interpolation. This is mainly done for radio telescope back end in which we need 4 or 8 small channels from a big IF coming in. Can any one help me t...

Polyphase filter questions

Hi, Hoping some of you experts can shine some light on the following regarding polyphase filtering 1...I created a polyphase FIR interpolator, sampling frequency is upsampled by 10 from 10KHz to 100KHz. It works fine and I get the required frequencies output on the scope. I notice however, ...

Polyphase FFT Filter bank

Hi, I would appreciate if someone could help me by advising me on the implementation of a polyphase FFT filter bank on a FPGA. I understand the basic fundamentals & computationally-efficient/improved side-lobe rejection advantages of polyphase fft filter banks. My implementation is based on a p...

Re: Polyphase decimation filter, is it only a mathematical gimmick?

Yes. The polyphase technique is a way of achieving the same output with a reduced number of arithmetic operations. ...

polyphase channelizer

hi all, I'm trying to build a polyphase channelizer in matlab using a prototype filter(sqrt nyquist) as my school project. Can anyone please explain this concept more precisely to me and what are the important things I should consider when implementing. Thank You. Riddhi ...

Regarding polyphase IIR filter.

Dear All, Iam working subband acoustic echo cancellation.In that for subbanding the input signal i used polyphase IIR filter.I searched in net for polyphase IIr filter design.I got some techinical documents related to polyphase IIr filter, I mentioned important links related to do...

polyphase filterbank

Does any have an efficient implementation of polyphase filterbank in C? M=32 thanks Andrew ...

regarding polyphase IIR filter.

Dear All, This is the my first mail to post our group.Iam working on subband acoustic echo cancellation.In that for subbanding the input signal 2 path polyphase IIR filter is used.I searched for polyphase IIR filter design in net I got some techginical documents.In those documents one doc...

Group Delay of Polyphase FIR filters

Could anyone explain or point me to any literature that explains how to compute the group delays of polyphase FIR filters used for decimation and interpolation? For example if an FIR filter with (N*L) coefficients is implemented as L polyphase filters each with N coefficients, what is the grou...

Polyphase FFT

I have a few programs that compute and display a running waterfall of an audio signal input to the PC sound card. The waterfall is computed via ordinary FFTs up to 1048576 points for the highest resolution settings. Recently I have seen a similar program that uses polyphase FFTs and it has a sp...

Polyphase FIR implementation

Hi, does anyone know if there is any reference code which implements a generic polyphase FIR resampler (up/down scaler), using Altivec instruction set? I searched the web (as usual), but I could not find anything really usefull, actully I did not find anything at all. Also non-obvious se...

clocks used in polyphase interpolation scheme

Greetings, I am trying to understand how the clock domains work during interpolation using the polyphase structure. Does one use 2 different clocks during implementation(lets say an interpolate by 2 FIR filter). One at the input and one at the output which is 2x the input clock. IS th...

Polyphase interpolation on an image with real value only

Hi all, I encounter some "problem" while using polyphase filter for interpolation. I have implemented a 8 zero crossing with upsampling of L=32. The image I used are a simulated image with 4 sinc impulse response near the four corner. All pixels values are positive. While performing ...

Scaling of fir polyphase filters

In a FIR filter the scaling of the input in order to avoid overflow at the output can be specified by using the 1st norm of the vector of coefficients. ymax=xmax*scaling*norm_1 for xmax=ymax=1 scaling=1/norm_1 How to use this relation in a multistage interpolator with polyphase decomposition...

VHDL source code for polyphase filter

Hello, Where can I find the VHDL ( or verilog) source code for polyphase filter? Is there any free implementation around? Regards ...

why do we need Polyphase decimatation filter?

I did a decimator FIR filter simply by doing the convolution only once every M' input sample. for example M=3: feed x0,feed x1, feed x2, convolution, feed x3,feed x4, feed x5, convolution, feed x6,.... Then I find many people talk about polyphase decimation filter, I wonder if it is more effi...

Re: Interpolation with FIR filters

in article 1132685207.779486.257470@o13g2000cwo.googlegroups.com, Anshu at anshu.dhawan@gmail.com wrote on 11/22/2005 13:46: > Can anyone please explain me about Interpolation using FIR filters? I > dont understand how they can be used for interpolation. might you understand how an FIR fil...

Re: Polyphase decimation

Praveen wrote: > Hi > > I am implementing a polyphase decimation of a 8k signal by a factor of > 20. I have designed a filter of pi/20, which means there are 20 > subbands. In case of decimation, the input gets shifted by a sample at > each time instant and then convolved with all the...

Re: multirate filter design

jon8spam@yahoo.com wrote: > Hi, > When one designs a fractional rate change filter, when specifying > the filter parameters do you design the filter at the interpolated > rate or the decimated rate? > > For example if you have an input rate of Fs then interp by 64 > decimate by 12...

best method for implementing an SRC

Hi, i would like to know which is the best method for implementing a integer sample rate converter (decimation /interpolation) in terms of quality. the conversion rates required are (2,4,8,16) both decimation and interpolation.i had tried with polyphase implementation and lagrange interpolatio...

FMDemod, Phase noise and Polyphase

Hi All, I am trying to debug a FM demodulation noise problem for a FPGA prototype. The output in general looks ok, but the THD+N of a clean 60% modulated signal is only in the mid-40's dB (noticable even by ear), and that is mainly due to a high noise floor. The FM architecture is using the d...

CIC versus Polyphase FIR

I am trying to understand the real benefits of using a CIC filter for rate sample change v.s a conventional multi-rate FIR filter. My thoughts on CIC v/s traditional sampling rate conversion methods below: I understand the multiplier-less advantage of CIC filters. However, because of their spectr...

Polyphase decimation errors

Folks, I understand that, based on the Nobel Identities, the output of a polyphase decimator should be identical to the output of a basic FIR decimator. This is due to the fact that even though we decimate in the full input bandwidth all the undersampled aliases will exactly cancel in the fina...

Intel's polyphase resampling function

Hi, All. I'm trying to use Intel's IPP polyphase resampling functions. They are part of the signal processing set and found in the manual under Speech Recognition Functions. I've found the manual's usage description somewhat lacking. I don't understand it well enough to implement. Can an...

uniform filter bank implementation.

I have a question with regards to going from a polyphase decimation routine and adapting it to an actual filter bank to separate a large bandwidth into smaller subbands. I understand how polyphase filters works, that no problem, I am just stuck on seeing how you make the transistion to a MxL (...

Regarding Acoustic Echo Cancellation with subbanding

Dear Sir, I am working on Acoustic Echo Cancellation. I have implemented both AEC without subbanding and AEC with subbanding in C+ +. For subbanding of AEC I used Polyphase IIR filter(with 70dB attenuation). AEC without subbanding is working fine. But in the outputs ...

Re: Farrow interpolation in QPSK synchro

Let me try to summarize Farrow's idea in three bullet points: The numbers are from the reference. * I can use a FIR filter to interpolate one particular point between samples, for example at an offset of 1/32 sample time * I keep 32 different banks of FIR coefficients at hand, so that I can c...

Polyphase decimating filter - not working - why?

Hello...I created a polyphase decimating filter based on F.Harris's book shared register design. This is a Decimation by 2, 100 tap, Fs =100MHz, Low pass 20MHz - stop band 24MHz filter. Each MAC is 28-bit length, 14-bit ADC input, and the filter output is truncated. The filter looks good a...

Re: non integer interpolation

On Aug 6, 9:25 pm, "chivak" wrote: > Hi All, > > I am trying to understand how a non-integer interpolating filter works. > For ex: In a 1.5 case, you would upsample by 3 and then down sample by > 2. > > How is the convolution between input samples and filter coefficients >...

Re: Interpolation/FIR/etc... =]

Hello, agree. Here is one reference: http://www.signumconcepts.com/IP_center/paper018.pdf I've got some slides here, mostly for my own use: http://www.elisanet.fi/mnentwig/multirate.pdf Those aren't polished, the polyphase filter is on page 15/16. In case of discrepancies, I'd tend to be...

Re: Polyphase filter questions

Scaling the output up by a factor N, certainly improves things. Many thanks to all in comp.dsp especially Fred for their help. Now, next problem..... Best Regards Duncan ...

Re: symbol timing recovery using interpolation filter method:suggestion

On 18 Oct 2005 03:39:08 -0700, asnivas223@gmail.com wrote: > Hi, > first of all i thank you all for your explanation, one thing i want > to ask is that in Gardners paper he is taking only 2 samples/symbol. > But i am having 16 samples/symbol or it may vary depending upon the > incoming sig...

Re: half band filter

I forgot to note in my previous message: this implementation method is called "polyphase" FIR filtering. Jason ...

Polyphase decimating filter - not working in lab- why?

Hello... I created a polyphase filter filter based on F.Harris's book shared register design. This is a Decimation by 2, 100 tap, Fs =100MHz, Low pass 20MHz - stop band 24MHz filter. Each MAC is 28-bit length, 14-bit ADC input, and the filter output is truncated. I also created a Xilinx d...

Re: Downsampe and convert stereo file to mono file.

Question for Erik, Julius, or someone else in the know: Erik's web page says (http://www.mega-nerd.com/SRC/quality.html): "SoX provides three methods of resampling; a linear interpolator, a polyphase resampler and the Julius O. Smith simulated analogue filter method." What's the differenc...

Polyphase & wavetable playback?

Hi. I am looking to add "wavetable" playback of sampled music/instruments to an existing project. The design already uses an FPGA & has an audio CODEC which supports playback at 48 kHz. I want to implement pitch-shifting and mimic higher/lower notes by altering the playback rate of the sam...

Re: Filter-banks: efficient splitting?

The magic words you want to Google are: polyphase DCT filter bank -- Matt ...

Re: FIR design

Randy Yates writes: > julius writes: > > > On May 31, 8:14 am, Jerry Avins wrote: > > > Is your filter symmetric (or antisymmetric)? If so, you can replace half > > > the multipliers with adders (or subtracters). > > > > > > Jerry > > > > Or, use something like the Canon...

Re: need interview questions for a DSP based embedded systems position

"siddharth.vaghela@gmail.com" writes: > thank u for the reply :) > thts wht i am doing exactly.. preparing my basics well and trying to > get my hands on simple programs on fir filters, bit reversals, etc etc. > i do get confused sometimes bcoz of the sheer size of material to be > re...