16
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How to implement Polyphase filter?
I assume that the Polyphase filter shown in the paper is used as a decimator such that the output rate is an integer fraction of the input rate (and this would make sense in a correlation operation ...
- 55k
4
votes
How to implement Polyphase filter?
The technique in the paper may be misnamed (or does not fit the normal use of polyphase filtering for resampling).
Normally when a window is made shorter than the FFTs length (by zero-padding, etc.), ...
- 35.7k
4
votes
The z factor in polyphase decomposition
The polyphase components of $h[n]$ are
$$e_k[n]=h[Mn+k]\tag{1}$$
Note that if $h[n]$ starts at $n=0$, then so do all polyphase components $e_k[n]$. In order to get back the original sequence $h[n]$ ...
- 92.5k
4
votes
The z factor in polyphase decomposition
These relationships are known as the multirate Noble Identities where in general you can change the order of an upsampling and delays if you change the exponent of the delay elements appropriately.
(...
- 55k
4
votes
Accepted
Polyphase Decimation Filter parallel inputs
Problem Statement and Bottom Line of Solution
As described, the OP wishes to channelize the input bandwidth that extends from DC to fs/2 (f = 0 to +1.25 GHz) into four channels each having one quarter ...
- 55k
4
votes
Efficient parallelized polyphase decimation FIR filter
Assume you do a polyphase decomposition into $M$ shorter filters, because that's really the best you can do in exploiting the decimation properties of your system.
Your $M$ shorter filters are just ...
- 32.5k
4
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What is the difference of each frequency response of partial filters in a polyphase method
The short answer is the polyphase filter converts a low pass filter into a series of all pass filters each with a different time delay. So it is a series of delays at even fractions of the time ...
- 55k
4
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Polyphase FFT example implementation
If you only have N points you cannot do better than an N point FFT does. What the polyphase does is to collect more data ...
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3
votes
Upsampling with time offsets
Answer: You will see residual images of $X(f)$ at multiples $f_s$, $2f_s$ and $3f_s$, and distorted image of $X(f)$ at non-zero multiples of $4f_s$, when sampling in the manner you explained. ...
- 2,621
3
votes
Polyphase filter bank channelizer FFT or IFFT
Forward DFT and Inverse DFT are quite similar transforms related by the following:
Let $x[n]$ be a length $N$ sequence, $X_f[k]$ be its N-point forward DFT, and $x_i[k]$ be its N-point inverse DFT : (...
- 28.4k
3
votes
Accepted
The z factor in polyphase decomposition
Note that the delay in the figure $4.37$ does not represent a commutation of delay $z^{-k}$ and an expander, but a commutation of delay $z^{-k}$ and polyhase branch filter $E_k(z^M)$ which is an LTI ...
- 28.4k
3
votes
Accepted
Polyphase Filter decomposition. It is not working
The following is a working code that uses 32-component polyphase decomposition of the associated 32-channel anslysis and synthesis filterbanks. As I have already commented, the speed gain is not ...
- 28.4k
3
votes
Relative Computational Complexity for Channelizer Implementations
For sufficiently long filters, it's usually more efficient to implement the individual filters as FFT-based fast convolution, indeed!
Now, whether something is faster than something else really doesn'...
- 32.5k
2
votes
How to implement Polyphase filter?
You can use this code to perform tests (for Matlab or Octave).
This basically writes down two sinusoids, and analyzes them following the very procedure as in https://casper.berkeley.edu/wiki/...
- 21
2
votes
Fractional Delay using Polyphase Filter
Since the question was how to specifically implement this with a polyphase filter, I offer the following:
Such a true polyphase filter structure could be done by designing the base FIR filter with 9*...
- 55k
2
votes
Fractional Delay using Polyphase Filter
Just sample a Sinc function at the appropriate phase offset, and truncate the FIR as needed to meet your rectangular window length requirement. You only need 1 phase for a constant delay while ...
- 35.7k
2
votes
Implementation of CIC filter using floating point
Heh. I've just worked this out, and I think you can implement a CIC using floating point -- but it wouldn't be perfect, and in most processing environments it would be a waste of resources.
The basic ...
- 13.3k
2
votes
Accepted
Use of DFT for Decimating Channelizers
As explained in detail at this post, an N-point DFT is functionally a bank of $N$ unity gain coefficient filters ("moving average" filters), each centered on $f_s/N$ where $f_s$ is the ...
- 55k
2
votes
Accepted
doppler tolerant phase coded waveforms
You should really read this paper, Phase Coded Waveforms for Radar, on doppler tolerance and phase coded waveforms.
I'll summarize section 5 on doppler intolerance for phase coded waveforms. PC ...
- 1,784
2
votes
doppler tolerant phase coded waveforms
The ambiguity diagram is used to analyze the result of pulse compression when receiving a Doppler-shifted version of the original waveform. I am not sure why you want to avoid the ambiguity diagram ...
- 2,936
1
vote
Implementation of CIC filter using floating point
See this post from Robert Bristow-Johnson, I think he posts on this stack exchange group by the way.
https://www.dsprelated.com/showthread/comp.dsp/364544-1.php
This post is about moving-average ...
- 3,797
1
vote
Direct and Transpose Polyphase Multirate Processing
The antialiasing filters here are FIR so there's no difference in the order of operations. If they were IIR there would be implications, see NUMERICAL ROBUSTNESS OF TDF-II. I think the classical ...
- 186
1
vote
Polyphase filter bank channelizer FFT or IFFT
To start with, XAPP1161's developers re-use, for their transmitter and receiver blocks, the objects dsp.ChannelSynthesis and dsp.Channelizer, respectively. These are objects of MATLAB's DSP System ...
- 1,774
1
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Polyphase filter bank channelizer FFT or IFFT
Sorry, I didn't read the paper so this is just a guess.
FFT and IFFT are almost identical algorithms so it really makes no sense to code up both in an FPGA. Just use
$$F^{-1} (x) = F(x')/N, \\ F(x) = ...
- 48.2k
1
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Decimating Polyphase Filter in Simulink
For starters, there are Simulink blocks that support polyphase filtering, such as this one https://www.mathworks.com/help/dsp/ref/firdecimation.html.
If you still want to design your own block in ...
- 3,797
1
vote
Decimating Polyphase Filter in Simulink
Just to follow up on this, I believe I figured out one way to do what I was looking for shown below...if anyone has any other ideas feel free to share too
- 29
1
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How to perform convolution using polyphase structure
I am not quite sure, if i understand you question properly, it would be better if you ask with detail and maybe with a figure, nevertheless if you want convolution of co-efficents of the transfer ...
- 105
1
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Coherent averaging of polyphase components of a signal
Yes. Simply sum all the polyphase outputs and the sum result will have higher resolution.
Consider that each polyphase output is a delayed version of the same signal, so that if you commutated ...
- 55k
1
vote
What is the threshold to prefer polyphase channelizer over FIR filtering?
A polyphase channelizer is not a special kind of filter. It is a structure that works well when using filters in multi rate settings. Polyphase is a sampling rate conversion method that leads to ...
- 133
1
vote
Accepted
Polyphase components Spectrum formula in Discrete time
Let's start with your equation.
$$ P_k\left( e^{j\Omega} \right) = \frac{1}{L} e^{jk\Omega/L} \sum_{p=0}^{L-1} e^{-2 \pi j k p / L} H\left( e^{j(\Omega-2\pi p)/L} \right) $$
Do a little rearranging....
- 7,600
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