Sparse Solutions for Antenna Arrays

In the field of communication warfare, the use of transceivers with frequency hopping to avoid intensional interference is usual. As for the immunity to interference, such electronic countermeasure has excellent efficiency, but greatly increases the electromagnetic emission and, therefore, the station indiscretion. To overcome this problem, it is possible to make use of antenna arrays and interference cancellation algorithms that introduce nulls in the directions of interferers while keeping a constant gain in the direction of interest. Under some conditions, in this example or in any other antenna array application, the solution can be sparse. In this paper, we discuss the use of L0- nom or L1-norm constraints to obtain sparse solutions in antenna arrays.