Space-Frequency Orthonormal Compensation Method for GNSS Compact Antenna Array Designs

In the global navigation satellites systems, the trav-eling time determination of the travelling signals is the main task of the receivers. For precise positioning applications, the accuracy is expected to be less than 1 ns to limit the error to the centimeters level. Hence, the influence of the responses of the antennas cannot be ignored since they can introduce delays of the order of 10 ns, which translates into errors of a few meters. The problem becomes even more complex when compact antenna arrays are used since the mutual coupling between their elements is considerable. In this work, a signal pre-processing scheme for coupled antenna arrays to compensate their space-frequency responses is described and analyzed.