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Live Q&A with fred harris - Green FIR Filters with Large Ratio of Sample Rate to Bandwidth

Fredric J Harris - Watch Now - Duration: 29:48

Live Q&A with fred harris following his talk titled "Green FIR Filters with Large Ratio of Sample Rate to Bandwidth"
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fred_hSpeaker
Score: 1 | 3 years ago | 1 reply

adam,

The polyphase filter that implements a cascade of analysis and binary masked synthesis filter bank always has a longer delay that the direct FIR filter implementation... because you have gone through two filters between input and output....

What is interesting, there is a recursive form of the polyphase filter, one with non uniform phase and one form with linear phase (actually equal ripple approximation to linear phase) the linear phase version will present a reduced delay relative to the direct form FIR.... see my book and if interested... I can pass along the code for the M-Path Linear phase IIR filter bank...

adam.rex
Score: 0 | 2 years ago | no reply

I would be interested in the code for an M-path linear phase IIR filter bank.

Amit
Score: 0 | 3 years ago | no reply

Prof. Harris,
would it be possible to get the code for the M-Path Linear phase IIR filter bank

thanks

adam.rex
Score: 0 | 3 years ago | no reply

Can polyphase FIR filter design reduce delay compared to a non-polyphase FIR filter?

remco_at_itsonlyaudio.com
Score: 0 | 3 years ago | no reply

Boy did you bury the lead in the last few minutes!
So for a log spaced polyphase bank, do you keep the transition bandwidths equal to assure the 6 dB Nyquist overlap but scale the bandwidths by the square root multiplier? Wouldn't that lead to a varying number of coefficients for each polyphase bank?

magarac
Score: 1 | 3 years ago | no reply

thank you so much for great presentation dr harris ! I'm curious to learn more about polyphase filterbank for hearing aids which is topic of your upcoming paper, but did not catch when/where will it be published. also, some specifics about inband aliasing that might affect some processing like echo-canceller, etc...
thanks & best regards !

Stefano
Score: 0 | 3 years ago | no reply

Hi Fred,
It is always an immense pleasure listening to your talks.
Regarding RF direct sampling, what are your thoughts about one analog Hilbert transformer followed by 2 ADCs, rather than directly sampling RF with one ADC? With the first approach we would have the 2 ADCs running at half speed but never seen a system done in this way so far.
Thanks!
Stefano

13:33:31	 From  Emanuele Ziglioli : Happy dsp-versary Stephane!
13:36:39	 From  Thomas Wagner : david you are on!
13:37:07	 From  David Robinson : Sorry for that
13:37:16	 From  Thomas Wagner : No worries ;)
13:39:44	 From  Emanuele Ziglioli : Ric Losada? but that was zero paddin
13:51:12	 From  mnapier : The coefs are in a ROM.  You select them.
13:52:39	 From  Radu Pralea : prof. harris, you've mentioned your modified remez FIR designer. I was wondering how it compares with the Least Squares method (which also provides decaying lobes
13:54:17	 From  kclifford : I like Least Squares as well. Also one can add e.g. time domain constraints.
14:00:33	 From  Radu Pralea : great, thanks!
14:00:46	 From  kclifford : Thanks, much appreciated!
14:01:27	 From  Jeff Cannon : Great information.  Thanks, fred!
14:01:44	 From  magarac : thank you so much for great presentation dr harris ! I'm curious to learn more about polyphase filterbank for hearing aids which is topic of your upcoming paper, but did not catch when/where will it be published. also, some specifics about inband aliasing that might affect some processing like echo-canceller, etc...
thanks & best regards !

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