针对复杂环境下无人机路径优化算法收敛精度低、全局搜索能力弱及易陷入局部最优解的问题,提出了一种改进混合蜣螂优化算法(SPM and osprey based hybrid dung beetle optimizer,SO-DBO)。使用混沌映射SPM初始化种群位置,提高算法搜索...针对复杂环境下无人机路径优化算法收敛精度低、全局搜索能力弱及易陷入局部最优解的问题,提出了一种改进混合蜣螂优化算法(SPM and osprey based hybrid dung beetle optimizer,SO-DBO)。使用混沌映射SPM初始化种群位置,提高算法搜索效率。在滚球蜣螂种群有障碍模式和无障碍模式中分别引入动态全局勘探策略和随机角度策略,提升算法精度和全局搜索能力。在觅食蜣螂位置更新引入自适应T分布策略,增强算法逃离局部最优能力。通过动态权重因子提高算法全局搜索能力并降低陷入局部最优解的风险。实验结果表明:相比原始蜣螂优化算法(dung beetle optimizer,DBO)和粒子群算法(particle swarm optimization,PSO),改进后的SO-DBO算法代价函数指标在简单环境下分别改善了9.68%、12.93%,在复杂环境下分别改善了13.34%、17.00%,有效提升了算法的收敛速度、精度和稳定性。展开更多
We propose a novel iteration-free blind phase noise estimation scheme for coherent optical orthogonal frequency division multiplexing （CO-OFDM） systems. In the new algorithm, the cost function is selected as the sim...We propose a novel iteration-free blind phase noise estimation scheme for coherent optical orthogonal frequency division multiplexing （CO-OFDM） systems. In the new algorithm, the cost function is selected as the similar expression with real and imaginary parts as that in the modified constant modulus algorithm, and the new cost function is derived under some assumptions, where it is infinitely approximated by the sine and cosine functions. By means of the analytical formula of the cost function, the initial coarse common phase error can be obtained with only some samples, where the algorithm avoids computational complexity of conventional blind phase noise compensation scheme. In CO-OFDM systems with high-order modulation format （32 quadrature amplitude modulation） and narrow linewidth lasers, it is proved by the simulation results that the nhase noise can be effectively compensated with the proposed blind estimation method.展开更多
基金supported in part by the China Postdoctoral Science Foundation(No.2013M540361)the National Natural Science Foundation of China(Nos.60907032 and 61275124)+1 种基金the Natural Science Foundation of Zhejiang Province(No.LY13F010011)the Zhejiang Youth Science Fund(No.LQ13F050005)
文摘We propose a novel iteration-free blind phase noise estimation scheme for coherent optical orthogonal frequency division multiplexing （CO-OFDM） systems. In the new algorithm, the cost function is selected as the similar expression with real and imaginary parts as that in the modified constant modulus algorithm, and the new cost function is derived under some assumptions, where it is infinitely approximated by the sine and cosine functions. By means of the analytical formula of the cost function, the initial coarse common phase error can be obtained with only some samples, where the algorithm avoids computational complexity of conventional blind phase noise compensation scheme. In CO-OFDM systems with high-order modulation format （32 quadrature amplitude modulation） and narrow linewidth lasers, it is proved by the simulation results that the nhase noise can be effectively compensated with the proposed blind estimation method.
