Antenna Array Based GNSS Signal Acquisition for Interference Mitigation

This work addresses the signal acquisition problem using an array of antennas in the general framework of Global Navigation Satellite Systems (GNSS) receivers. We propose a statistical approach, using the Neyman-Pearson (NP) detection theory and the generalized likelihood ratio test (GLRT), to obtain a new detector which is able to mitigate temporally uncorrelated interferences even if the array is unstructured and moderately uncalibrated. The key statistical feature is the assumption of an arbitrary and unknown covariance noise matrix, which attempts to capture the statistical behavior of the interferences and of other nondesirable signals, while exploiting the spatial dimension provided by antenna arrays. Closed-form expressions for detection and false alarm probabilities are provided. The performance and interference rejection capability are modeled and compared with their theoretical bound. Furthermore the proposed detector is analyzed under realistic conditions, which accounts for the presence of errors in the covariance matrix estimation, the residual Doppler and delay errors, and the signal quantization effects. The theoretical results are supported by Monte Carlo simulations.