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Nature-inspired algorithms attract many researchers worldwide for solving the hardest optimization problems. One of the well-known members of this extensive family is the evolutionary strategy ES algorithm. To date, many variants of this algorithm have emerged for solving continuous as well as combinatorial problems. One of the more promising variants, a self-adaptive evolutionary algorithm, has recently been proposed that enables a self-adaptation of its control parameters. In this paper, we discuss and evaluate popular common and self-adaptive evolutionary strategy (ES) algorithms. In particular, we present an empirical comparison between three self-adaptive ES variants and common ES methods. In order to assure a fair comparison, we test the methods by using a number of well-known unimodal and multimodal, separable and non-separable, benchmark optimization problems for different dimensions and population size. The results of this experiments study were promising and have encouraged us to invest more efforts into developing in this direction.

The combined system STBC-OFDM has considered an important association to integrate into actual and next wireless system. Such as the Wifi standard, WiMAX standard, the LTE fourth generation of mobile. Which combat the effect of multipath fading channel that limited the performance in wireless communications. In recent years, this association has been a large study to achieve a better performance of BER and designed for the different situation of the wireless channel from slow to fast fading channel, with various parameters of OFDM modulation and under different condition of STBC code. To contribute in this axis of research, we present a comparative study of the simulation result for STBC-OFDM. The first results are the comparison between three schemes of STBC (Alamouti code, Orthogonal STBC, Non-Orthogonal STBC) associated with OFDM. The second results are the comparison between three schemes when applied OFDM in different parameters and also when these codes used without OFDM modulation. The channel considered across simulation is Rayleigh fading channel that presented a real situation of the wireless environment, the Maximum Likelihood (ML) is used for detection the data that encoded in the first. The performance of three schemes is evaluated by BER (Bit Error Rate) versus the different values of SNR (Signal Noise Ratio).