Imperialist competitive algorithm for minimum bit error rate beamforming

In this paper, the recently introduced optimisation strategy, imperialist competitive algorithm (ICA) is used to design an optimal antenna array which minimises the error probability for binary phase shift keying modulation, called minimum bit error rate (MBER) beamforming. ICA is used to deal with the high complexity and high dimensionality of this challenging problem which can not be easily solved by gradient-based methods. The results are compared to that of both a genetic algorithm (GA) and the optimal array obtained by a properly set gradient based algorithm. Comparison shows that in contrast with GA, ICA leads to the array with error probability which is very close to the optimal value. Also, being faster than GA, ICA minimises the cost function with more consistency. The total results show that ICA is a powerful and reliable tool for solving complex optimisation problems such as MBER beamforming.