Abstrakt: |
Evolutionary algorithms (EAs) have recently been applied to Uncoded Space-Time Labeling Diversity (USTLD) systems to produce labeling diversity mappers. However, the most challenging task is choosing the best parameter setting for the EA to create a more 'optimal' mapper design. This paper proposes a 'meta-Genetic Algorithm (GA)' used to tune hyperparameters for the Labeling Diversity EA. The algorithm is examined on 16, 32 and 64QAM; 32 and 64PSK; 16, 32 and 64APSK and 16APSK constellations that do not show diagonal symmetry. Furthermore, the meta-GA settings and original GA settings are compared in terms of the number of generations taken to converge to a solution. For QAM constellations, the output using the meta-GA settings matched but did not improve with the original settings. However, the number of generations needed to converge to a solution took 120 times less than the number of generations using the original settings. In the 64PSK constellation, a diversity gain of ≈ 1 dB was observed while improving on the actual fitness value from 0.0575 to 0.0661. Similarly, with 32APSK constellation, an improvement in fitness value from 0.1457 to 0.1748 was made while showing diversity gains of ≈ 1 dB. 64APSK constellation fitness value improved from 0.0708 to 0.0957, and a ≈ 2 dB gain was observed. The most significant improvement was made by the asymmetric 16APSK constellation, with gains of ≈ 5 dB and increasing its fitness value three times (0.0981 to 0.3000). A study of the effects of optimizing the GA parameters shows that the number of swaps during crossover (K) and the radius (ℜ) were the two most important variables to optimize when executing this GA. [ABSTRACT FROM AUTHOR] |