Functional Bandwidth Criterion for Adaptive Array Performance

The bandwidth of an interference source affects the performance of an adaptive array. The nature and degree of this effect, however, depends on the application considered. To analyze the bandwidth´s effects correctly, therefore, a metric that reflects an adaptive array´s performance for that application must be chosen. This paper employs a quantity known as the percentage of available sky (PAS) to analyze the bandwidth´s effects on the performance of an adaptive array with a GPS receiver for GPS signal detection and tracking. The PAS, an important performance metric in GPS applications, is the fraction of area on a unit hemisphere where GPS signals are available for detection and tracking. The methodology to obtain the PAS for the minimum variance distortionless response (MVDR) beamformer is outlined. Results are presented that show how various system parameters influence the bandwidth´s effect on the PAS. A comparison of the results from the PAS with the currently accepted criterion for bandwidth classification shows that the latter is not a reliable indicator of bandwidth effects on beamformer performance for GPS signal detection and tracking.