Nonuniform Tap Spacing in a GPS Spherical Adaptive Array

This letter introduces a signal processing procedure that improves the performance of the basic Global Positioning System (GPS) receivers. The proposed signal process incorporates fixed nonuniform tap delays to a seven-element spherical array to mitigate the degrading impact of multipath propagation in satellite communications. Contrary to the time-consuming tap-delay-tracking algorithms, the proposed nonuniform tap delays do not increase the complexity of the signal processing when compared to those of the uniform spaced delays. Using standardized channel models, it is shown that, for a bit error rate (BER) of 10 $^{-3}$ , the system can operate with 1–2 dB less signal-to-noise ratio (SNR) when an exponential distribution is used instead of the uniform.