A New Quantum Clone Genetic Algorithm Based Multi-user Detection for CDMA System

Quantum intelligent computation has been widely drawing the attention of many researchers. Quantum clone genetic algorithm ,which is based on quantum genetic algorithm and clone algorithm, is a new quantum intelligent algorithm with good performance. In order to overcome the shortcomings such as low efficiency, poor population diversity, slow convergence speed, easy to trap in local minimums, and blindness in global optimal searching direction etc, a new quantum clone genetic algorithm (NQCGA) is proposed in this paper. Results of optimization experiment about the function extreme demonstrate that NQCGA have many merits: (1) Adopting nicking probability division initialization strategy, the population diversity is enhanced; (2) Introducing quantum whole interference crossover, the information is spread in the whole population, so it helps to avoid trapping in local minimums, and accelerates convergence speed; (3) Making use of adaptation strategy in quantum rotate gate updating, the searching speed for optimal solution is accelerated; (4) Adopting the superior individual whole crossover quantum catastrophe strategy ,it helps the algorithm to avoid premature and evolution stagnation, and helps the population to search the objective solution in different directions. Finally, a new multi-user detection based on NQCGA for CDMA system is put forward in this paper. Simulation results prove that the given multi-user detection has lower bit error, rapider converge speed, better resisting MAI ability、 better Near-far Resistance ability and larger system capacity than other multi-user detections based on quantum clone genetic algorithm and classical genetic algorithms obviously.