A method and system uses a constrained set of indexed samples to identify a next generation population of samples that exhibits a more desirable signal characteristic. The invention generates an intermediate set of indexed samples which are subjected to a fitness function and next generation calculations to produce next generation indexes for the next population of samples. The next generation indexes population of samples is further constrained over initial indexes for generating a more desirable signal characteristic. In an example, the PAPR for all samples of the population are reduced.