Here's some stuff I wrote up while I was trying to figure out Aaron's FFT magic which might be useful to others. Read at your own risk of course. http://www.eecs.berkeley.edu/~sgowda/parallel_fft_algorithm.pdf -Suraj
On Mon, Jun 23, 2014 at 11:43 AM, Aaron Parsons < [email protected]> wrote: > Hi Stevo, > > The short answer is that there aren't any papers I know of that went into > more detail on the math (I certainly didn't write one). However, the > decomposition of a large FFT into smaller FFTs is a standard property of > the the radix-2 (and generally, radix-N) FFT algorithm. > > The reordering and phase shifting is absolutely necessary to preserve the > phase relationships between all the various frequencies in the band. > > Aaron > > > On Thu, Jun 19, 2014 at 2:10 PM, Stevo Bailey < > [email protected]> wrote: > >> Hi CASPERians, >> >> I'm working on a digital ASIC spectrometer like the Splash >> <https://casper.berkeley.edu/wiki/PIDDP_Spectrometer> one, but >> constructed in Chisel <https://chisel.eecs.berkeley.edu/> instead of the >> CASPER tools. Thus I'm implementing a number of DSP algorithms from >> scratch. I'm trying to work out the math behind a large-point FFT block. >> From my understanding, it consists of a number of biplex pipelined FFTs in >> parallel, followed by some reordering or phase shifting (is this >> necessary?), then followed by an in-place FFT. I have the biplex FFTs done. >> I'm looking for documents or publications discussing the math behind >> combining the parallel FFT results for the in-place FFT. Aaron has a >> paper <http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4840623> >> on this, but I was hoping for one with more detail. >> >> Thanks! >> Stevo >> > > > > -- > Aaron Parsons > 510-306-4322 > Hearst Field Annex B54, UCB >
