Robust blind adaptive array. A prototype for GPS

A receiver that incorporates an adaptive antenna array is presented. The system is designed to receive direct sequence spread spectrum (DS-SS) signals from the satellites of the NAVSTAR Global Positioning System (GPS) and to operate mounted on a mobile platform. Different from the conventional adaptive antenna for CDMA systems, the prototype presented here performs the array processing after the de-spreading. This approach diminishes the data rate provided to the processor that adapts the beamforming, and therefore it allows the use of low cost microprocessors. The adaptive beamforming implements a blind algorithm based on the non-stationarity of the linear modulated digital signals and a pseudo-PRO-ESPRIT algorithm but without any restriction in the geometry of the array. The algorithm estimates the weight vector that achieves the maximum SINR. It is shown that its convergence is faster than Phase-Score which is the only algorithm with comparable performance. Experimental data that show the performance of the whole system are also presented