A Genetic Algorithm for the Optimization of the Analog Channel Filter

This paper presents a method for optimizing the transfer function of the channel filter within the Zero-Intermediate Frequency radio receivers of Orthogonal Frequency-Division Multiplexing (OFDM) broadcasts. The method is based on a genetic algorithm (GA) and has several distinctive features: the type and order of the transfer function can be changed during the optimization process; the optimal solution is calculated based on three objective functions that allow an independent control of the pass band and stop band; a real test signal including wanted and adjacent channels is applied at the filter’s input, which allows the estimation of the nonlinearity effects of the filter. Another important feature is that for a given set of conditions, the GA is run multiple times, taking full advantage of the random permutations employed by the algorithm: the multiple results are not only used to select the very best but they are also analyzed statistically in order to estimate the convergence of the algorithm.