Antenna array system with disparate beam forming networks and non-linear filtering to mitigate interference

A method for suppressing a plurality of interference signals received by an antenna array that concurrently receives a desired signal, the method comprising:

• receiving N antenna signals from the antenna array, wherein the antenna array comprises N antenna elements, where N is greater than one;
• obtaining respective arrival directions of the interference signals upon the antenna array;
• applying each of a plurality of nulling beam weight sets to a respective one of N null beam forming networks (null BFNs) of an interferer-nulling beam forming network coupled to the antenna array to generate N null signals, wherein each nulling beam weight set corresponds to a different respective set of (N−1) independent nulls corresponding to (N−1) of the arrival directions, such that within each null signal, (N−1) of the interference signals are suppressed with respect to each of a remaining one of the interference signals and the desired signal;
• filtering each of the N null signals using a respective one of N non-linear filters to suppress the respective remaining one of the interference signals with respect to the desired signal, thereby generating N filtered signals;
• combining the N filtered signals to generate an output signal corresponding to the desired signal;
• operating in a first mode using the plurality of beam weight sets when a number of interference signals is equal to N, and operating in a second mode when the number of interference signals is less than N;
• in the first mode, providing the respective nulling beam weight set to each of the null BFNs, and providing a desired signal beam weight set to a desired signal beam forming network to combine the filtered signals to generate the output signal;
• and
• in the second mode, providing a collective beam weight set to a particular null BFN of the null BFNs, wherein the collective beam weight set corresponds to independent nulls aligned to arrival directions of the interference signals and a beam peak aligned with an arrival direction of the desired signal.