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A Single-Chip Narrowband Frequency Domain Excisor for a Global Positioning System (GPS) Receiver
August 1999
Paul T. Capozza, Member IEEE
Brian J. Holland, Member IEEE
Thomas M. Hopkinson, Member IEEE
Roberto L. Landrau, Member IEEE
ABSTRACT
In recent years, we have witnessed the rapid adoption of the Department of Defense’s Global Positioning System (GPS) for navigation in a number of military and civilian applications. Unfortunately, the low-power GPS signal is susceptible to interference.This paper presents a novel VLSI architecture that removes narrow-band signals from the wide-bandwidth GPS spectrum. The interference suppression technique employed is frequency-domain excision. The single-chip frequency-domain excisor transforms the received signal (GPS signal + noise + interference) to the frequency domain, computes signal statistics to determine an excision threshold, removes all spectral energy exceeding that threshold, and restores the remaining signal (GPS) signal + noise) to the temporal domain. The heart of this VLSI implementation is an on-chip 256-point fast Fourier transform processor that operates at 40 million complex samples per second. It processes 12-bit (for each and ) sampled complex data. The 1.5-million-transistor chip was fabricated in 0.5- m CMOS triple metal technology and is fully functional.
Additional Search Keywords
Adaptive narrow-band filter, frequency-domain excision, frequency-domain inteference suppression, GPS
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