Citation
Abstract
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.
Details
- Volume
- 42-107
- Published
- November 15, 1991
- Pages
- 132–140
- File Size
- 501.0 KB