I'm an EE from USC with mostly a software career. My hobbies of robotics and mechatronics have kept my EE skills reasonably sharp. My current role is architecting software for SDRs so I get to get DSP too!

Re: Impulse response of CIC filter

Reply posted 3 days ago (01/22/2020)
How did you choose how to do the interleaving?

Re: Test signal names

Reply posted 6 days ago (01/19/2020)
I like that, impulse prime. I'll use that name in my code, thanks!

Test signal names

New thread started 6 days ago
So I've used the "unit impulse" (which is a 1.0 magnitude sample followed by zeros) to test filters, and a "unit step" (50% of the samples are 0, the remaining 50%...

Re: Impulse response of CIC filter

Reply posted 1 week ago (01/15/2020)
Your right it does. Now nothing I've read about CIC filters talks about polyphase. That is something I need to understand, can you point me to a reference?And as...

Re: Impulse response of CIC filter

Reply posted 1 week ago (01/15/2020)
Ok, that is pretty awesome!

Impulse response of CIC filter

New thread started 1 week ago
So this is a curious one. I am continuing investigating #CIC filters now that I have run @Rick Lyons tests and proven to myself that they are now correctly implemented....

Re: #CIC filters and testing them

Reply posted 2 weeks ago (01/13/2020)
Rick,Thank you so much for your patience. You have helped connect a number of dots for me (that explanation of the diagram is brilliant).For other readers of this...

Re: #CIC filters and testing them

Reply posted 2 weeks ago (01/13/2020)
Hi Rick, [Side note: the pictures are awesome!]Your understanding is correct. Having the two pictures is also pretty cool since its easier to see how diagrammatically...

Re: #CIC filters and testing them

Reply posted 2 weeks ago (01/12/2020)
This makes a lot of sense to me, although the use of the word phase is ambiguous. I have understood differentiators to be computing the slope (i.e. the first derivative)...

Re: #CIC filters and testing them

Reply posted 2 weeks ago (01/12/2020)
Hi Rick,There is certainly something different in the differentiators :-).From your first response I use M = 1, so the differentiator is looking at X(n) and Y(n...

#CIC filters and testing them

New thread started 2 weeks ago
Rick Lyons posted an informative post about testing the implementation of your #CIC decimation filters here: Two Easy Ways to Test Multistage CIC Decimation Filters...

CIC Implementation details

New thread started 4 weeks ago
I'm implementing a #CIC decimation filter. I'm doing it on an microprocessor rather than in an FPGA and that means I don't "easily" get variable bit width registers....

Re: What is cyclic frequency α?

Reply posted 2 months ago (12/06/2019)
Consider this copy for $104 (https://www.abebooks.com/servlet/BookDetailsPL?bi=...)Generally Abe Books is a much better source of old text books than Amazon.

Re: phase change

Reply posted 3 months ago (11/09/2019)
Are you asking for the idiomatic way to do this in a DSP or just what does the process involve?If you're synthesizing the waveform you can just bump the value of...

Re: New IEEE Signal Processing Society Journal

Reply posted 3 months ago (11/01/2019)
@stephanebIn my opinion the only to metrics for a "journal" are credibility and the ability to track down citations to papers in that journal.Sadly credibility has...
Assuming you have the spectrum in complex form you band pass filter out the 1700 Hz, multiple the result by a .5 Hz complex sinusoid and add the result back into...

Re: New IEEE Signal Processing Society Journal

Reply posted 3 months ago (10/29/2019)
I am always a bit annoyed by "pay to publish" journals. Especially if that journal then charges extortionately for people to get copies of the papers. Given that...

Re: small DSP ?

Reply posted 3 months ago (10/26/2019)
Actually the Teensy 4 is pretty reasonable for this. I've got the Digilent I2S PMOD board which can do 192 kSPS in stereo.

Re: concept of bandwidth

Reply posted 3 months ago (10/21/2019)
Hi Sharan, make your data complex with the real component being MAXVAL and your quadrature component being randomized. That will spread the signal across the entire...

Re: Understanding cascaded integrators

Reply posted 3 months ago (10/20/2019)
Hi Chalil, It is helpful, thank you. In this particular case I am relying on the 32 bit nature of the registers to deal with overflow.The math question though is...

Re: FFT of a sine wave signal

Reply posted 3 months ago (10/20/2019)
Per Achilles comment, the FFT is always complex, even if you feed it a purely real signal. When you combine that with the understanding that a complex signal that...

Understanding cascaded integrators

New thread started 3 months ago
Hi All,I am working my way though the design and implementation of a #CIC filter to process the output of a PDM waveform (coming from a MEMS microphone). I know...

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