Integrated adaptive antenna array and adaptive locally-optimum detection system

Abstract

A system is provided which combines the advantages of Adaptive Antenna Arraying and Adaptive Locally-Optimum Detection, as well as Adaptive Filtering, signal processing techniques and achieves the capabilities of all these techniques. The present invention represents the first successful integrated system for performing signal processing techniques associated with an Adaptive Antenna Array (AAA) system and an Adaptive Locally-Optimum Detection (ALOD) system. The system automatically distributes interference signals among Adaptive Antenna Arraying and Adaptive Locally-Optimum Detection sub-systems according to which sub-system's algorithms can provide a more optimum suppression of the interference signals. The system permits an adaptive antenna array with a given number of antenna elements to effectively suppress a larger number of interferers than it otherwise could, and to adapt more quickly to a rapidly changing interference scenario. For an adaptive antenna array with a small number of antenna elements, e.g., two to four, the system provides added interference suppression capability than could be done by adding antenna elements to the adaptive antenna array. The system is primarily designed for incorporation within systems using Direct Sequence Spread Spectrum signals, such as Global Positioning System (GPS) signals. In a preferred embodiment the inventive system is incorporated within a conventional GPS receiver which tends to be vulnerable to jamming by interference signals.