The optimal loading of robust adaptive beamforming based on worst-case performance optimization

In this paper the robust adaptive beamforming (RARF) based on worst-case performance optimization is investigated. This method belongs to the class of diagonal loading approaches and determines the loading level by optimizing the worst-case performance. Other than solving the optimal loading by iteration, as many existing methods in this field did, we derive a simple closed-form solution to the optimal loading after some approximations. In addition to reducing the computational complexity, this simple analytical solution reveals how different factors affect the optimal loading, Numerical examples confirm that the closed-form expression is a very accurate approximation to the actual optimal loading.