In this paper we present a methodology for blind source separation (BSS) based on the coherence function to solve the problem of linear instantaneous mixtures of signals. The proposed methodology consists in minimizing the coherence function using a heuristic algorithm based on the simulating annealing method. Also, we derived an analytical expression of the coherence between the BSS model in which is found that independent and identically distributed (iid) Gaussian components can be recovered. Our results show satisfactory performance in comparison with traditional methods.