Polyphase in Practice

Started by Fred Marshall in comp.dsp12 years ago 21 replies

As some may have noticed, I have a particular interest in frequency multiplication filtering methods - among other things. So, you can imagine...

As some may have noticed, I have a particular interest in frequency multiplication filtering methods - among other things. So, you can imagine my slight bias when looking at polyphase filters. I think Rick Lyon's book puts polyphase filters into a very nice perspective! I highly recommend it to all. In doing filtering in "batch" mode I can imagine a (temporal) "polyphase" filter as...


Polyphase FIR interpolation filter

Started by kungcoccos in comp.dsp10 years ago 4 replies

Hello! Im looking for a simple matlab code that illustrates an interpolation using polyphase implementation. I need this to understand the...

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 FFT Filter bank

Started by schadenfreud in comp.dsp9 years ago 4 replies

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...

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 polyphase decimation by D FIR filter and the end application is to split the input ADC samples into '...


polyphase filtering

Started by jith...@yahoo.com in comp.dsp13 years ago 6 replies

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...

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 to find wht exactly is polyphase filter. ie whether the filters in the bank is linked with each othe...


Regarding polyphase IIR filter.

Started by venkat in comp.dsp11 years ago

Dear All, Iam working subband acoustic echo cancellation.In that for subbanding the input signal i used polyphase IIR filter.I...

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 documents below. 1 http://users.cscs.wmin.ac.uk/~krukowa/pdf/Paper27.pdf 2http://ieeexplore.ieee.org...


Polyphase filter questions

Started by Anonymous in comp.dsp10 years ago 23 replies

Hi, Hoping some of you experts can shine some light on the following regarding polyphase filtering 1...I created a polyphase FIR...

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, that the output gain is much lower than that with a standard FIR sampled at 100 KHz with the same ...


Are all farrow filters polyphase filters?

Started by colin22 in comp.dsp5 years ago 1 reply

I know what a farrow filter is and I'm familiar with the efficient polyphase implementation, but the structures I've seen in articles about Farrow...

I know what a farrow filter is and I'm familiar with the efficient polyphase implementation, but the structures I've seen in articles about Farrow filters and the structures in the articles about "polyphase" Farrow filters look pretty much the same. I'm confused why the author would specify that a Farrow filter was a polyphase Farrow filter if all Farrow filters are polyphase. Could I have an exam...


Polyphase resampler jitter?

Started by gct in comp.dsp9 years ago 5 replies

I've got a polyphase resampler that I've built, and I'm noticing a lot of jitter in the output power spectrum that I'm having a hard time...

I've got a polyphase resampler that I've built, and I'm noticing a lot of jitter in the output power spectrum that I'm having a hard time tracking down. First a little about the resampler: It's designed so that the user provides an input signal, up/down values and a filter response, the program than generates 'up' number of polyphase legs and strides through, calculating every 'down' output samp...


Polyphase FFT

Started by Alberto in comp.dsp12 years ago 10 replies

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...

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 spectral leakage much lower than mine (I use a Blackman window). The subject of polyphase FFT is new ...


Polyphase Filter

Started by mishrask in comp.dsp5 years ago 4 replies

Hi , I am designing a polyphase filter in HW, which will do a sample rate upconversion by a factor of 1.25 on the incoming data.It is...

Hi , I am designing a polyphase filter in HW, which will do a sample rate upconversion by a factor of 1.25 on the incoming data.It is implemented as a upsampling by 5 followed by a decimation(polyphase)by 4(5/4=1.25)...For this design let's say I have a clock rate of 100kHz then I am not sure what will be the maximum limit on the input data sampling rate(Fs_input) which my design can handle ....


regarding polyphase IIR filter.

Started by ch.venkat in comp.dsp11 years ago 6 replies

Dear All, This is the my first mail to post our group.Iam working on subband acoustic echo cancellation.In that for subbanding the...

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 documents for 2 path polyphase IIR filter design related to acoustic echgo cancellation, The filter coe...


About RRC's polyphase structure

Started by zzp6682 in comp.dsp4 years ago 3 replies

Anyone know how to implement polyphase filter of the RRC? The RRC filter is designed with 17 taps. After modulation, the symbole rate is up 1Gsps,...

Anyone know how to implement polyphase filter of the RRC? The RRC filter is designed with 17 taps. After modulation, the symbole rate is up 1Gsps, we have to us polyphase structure to implement filter? How to do this ? _____________________________ Posted through www.DSPRelated.com


Polyphase Filtering Question

Started by westocl in comp.dsp8 years ago 1 reply

Im have a few question about polyphase filtering. Lets say you have a downsampling application. and in general with polyphase filtiering yoou...

Im have a few question about polyphase filtering. Lets say you have a downsampling application. and in general with polyphase filtiering yoou wish to exploit the efficiency assocationw it downsampling before invoking the lowpass filter. If you didnt do ployphase filtering, lets say you implimented a lowpass that was to reject frequencies above .2Fs and then did the downsampling to avoid ali...


Questions regarding polyphase filter

Started by bcarmaint in comp.dsp8 years ago 9 replies

I am try to get a better understand of polyphae filter. There are several questions I wonder if I can get some help: 1) Relationship of...

I am try to get a better understand of polyphae filter. There are several questions I wonder if I can get some help: 1) Relationship of polyphase filter and Different signal interpolation/decimation methods. One thing I am a bit confused about is the relationship between different curve fitting type interpolation methods (i.e., cubic bspline, cubic polynomial, linear etc.) and polyphase filter....


polyphase channelizer

Started by Riddhi in comp.dsp11 years ago

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...

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


Real usefullness of the polyphase form in DSP / CPU implementation of a decimator

Started by tsd82 in comp.dsp2 years ago 9 replies

Hello all, I read in a lot of papers that the polyphase form is the right way to implement a decimation filter, either on FPGA, DSP or...

Hello all, I read in a lot of papers that the polyphase form is the right way to implement a decimation filter, either on FPGA, DSP or CPU. But if I understand well why it is used in a FPGA (because it enables to have hardware resources working all the time at the lower rate, and not from time to time, but at the higher rate), I really cannot understand the usefullness of the polyphase form ...


polyphase filterbank

Started by Andrew Xiang in comp.dsp14 years ago 1 reply

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

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


Group Delay of Polyphase FIR filters

Started by dghosh in comp.dsp13 years ago 3 replies

Could anyone explain or point me to any literature that explains how to compute the group delays of polyphase FIR filters used for decimation...

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 group delay for the filter? Measured values indicate the group delay to be less than (N*L)/2 which is ...


Polyphase structure for interpolation

Started by Clay in comp.dsp5 years ago 6 replies

Hi everyone, I'm new to DSP and I have just been recently learning the concepts. And I don't really understand the polyphase filtering. I...

Hi everyone, I'm new to DSP and I have just been recently learning the concepts. And I don't really understand the polyphase filtering. I have to increase the sampling rate by a factor of 8, and I'm doing that in two stages: interpolate by 2 in the first stage, then by 4. I get the basic interpolation process which involves upsampling the signal by a factor of L (inserting zeros in between ...


Polyphase FIR implementation

Started by Piergiorgio Sartor in comp.dsp12 years ago 9 replies

Hi, does anyone know if there is any reference code which implements a generic polyphase FIR resampler (up/down scaler), using...

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 search hints will be appreciated. Thanks a lot in advance, bye, -- piergiorgio