No abstract

Narrowband and partial-band interference can severely degrade the performance of GPS receivers. The use of digital signal processing in a receiver has been shown to provide protection against this type of interference in communications systems and has been proposed for application in future GPS systems. This paper discusses the measured effects of narrowband interference suppression on GPS receiver performance. Emphasis is placed on its effects on pseudorange measurements, since navigation accuracy is ultimately the measure of interest to the user. Performance metrics presented include: the GPS receiver input carrier-to-noise ratio, receiver crosscorrelation function, and pseudorange errors. The results demonstrate that substantial interference suppression can be attained with modest navigation accuracy degradation by incorporating narrowband interference suppression technology into GPS receivers.

Publc reporting burden for this collection of inforiat~on is estimated to average 1 hour ner response. including the time for reviewing instructions, searching existing data sources, ga~thering and mantaining the data needed, and cOml:eting and revl~ing the collection of information. Approved for public release; distribution unlimited. ABSTRACT (Maximum 200 words)This paper presents a highly-integrated, high-precision FFT architecture. A 1.2 jm CMOS implementation of this architecture has yielded a 32-bit, 64K-point FFT that operates at a continuous 4-million-samples-per-second data rate. All FFT support functions, including coefficient generation and memory interfacing, are included on-chip.