English: Depiction of the implementation and operation of a Weighted Overlap Add (WOLA) channelizer (DTFT sampler). Wrap-around of a circular input buffer is used to offset phase discontinuities, caused by lack of a true time reference for the Fourier transform (DFT).[1][2]
La persona que ha associat un treball amb aquest document ha dedicat l'obra domini públic, renunciant en tot el món a tots els seus drets de d'autor i a tots els drets legals relacionats que tenia en l'obra, en la mesura permesa per la llei. Podeu copiar, modificar, distribuir i modificar l'obra, fins i tot amb fins comercials, tot sense demanar permís.
http://creativecommons.org/publicdomain/zero/1.0/deed.enCC0Creative Commons Zero, Public Domain Dedicationfalsefalse
Altres versions
This was supposed to be a .svg file, but .svg did not support the yellow highlighting.
With no frequency or time decimation, the channelizer's DFT stage (fixed time-reference) calculation would be:
With frequency decimation by 4 and time-decimation by 2, it becomes:
The phase-correcting sequence is equivalent to which repeats periodically.
The diagram shows that these corrections are produced automatically, by using the buffer's natural wrap-around characteristic as a time-reference. No buffer unwrapping logic or phase-correcting logic is required. Or, in other words (Multirate Digital Signal Processing, p. 321 ),
The modulation to convert the short-time spectrum from the sliding to the fixed-time references can be achieved without multiplication by recognizing that a modulo K shift of the (time-domain) sequence at the input of the DFT introduces a linear phase-shift of the DFT (frequency-domain).
Llegendes
Afegeix una explicació d'una línia del que representa aquest fitxer
Depiction of the implementation and operation of a Weighted Overlap-Add (WOLA) channelizer
Aquest fitxer conté informació addicional, probablement afegida per la càmera digital o l'escàner utilitzat per a crear-lo o digitalitzar-lo. Si s'ha modificat posteriorment, alguns detalls poden no reflectir les dades reals del fitxer modificat.