A 640-MHz 32-megachannel real-time polyphase-FFT spectrum analyzer
- Author:
- Grimm, M. J.
- Published:
- Nov 15, 1991.
- Physical Description:
- 1 electronic document
- Additional Creators:
- Garyantes, M. F., Charny, B., and Zimmerman, G. A.
Online Version
- hdl.handle.net , Connect to this object online.
- Restrictions on Access:
- Unclassified, Unlimited, Publicly available.
Free-to-read Unrestricted online access - Summary:
- A polyphase fast Fourier transform (FFT) spectrum analyzer being designed for NASA's Search for Extraterrestrial Intelligence (SETI) Sky Survey at the Jet Propulsion Laboratory is described. By replacing the time domain multiplicative window preprocessing with polyphase filter processing, much of the processing loss of windowed FFTs can be eliminated. Polyphase coefficient memory costs are minimized by effective use of run length compression. Finite word length effects are analyzed, producing a balanced system with 8 bit inputs, 16 bit fixed point polyphase arithmetic, and 24 bit fixed point FFT arithmetic. Fixed point renormalization midway through the computation is seen to be naturally accommodated by the matrix FFT algorithm proposed. Simulation results validate the finite word length arithmetic analysis and the renormalization technique.
- Other Subject(s):
- Collection:
- NASA Technical Reports Server (NTRS) Collection.
- Note:
- Document ID: 19920005032.
Accession ID: 92N14250.
The Telecommunications and Data Acquisition Report; p 132-140. - Terms of Use and Reproduction:
- No Copyright.
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