摘要
针对OFDM(Orthogonal Frequency Division Multiplexing)系统信道稀疏且稀疏度未知的特性,提出了一种新的稀疏度自适应压缩感知信道估计方法,即弱选择分段自适应匹配追踪(Weak Selection Stagewise Adaptive Matching Pursuit,WSStAMP)算法。该算法结合了原子预选和变步长的思想,在初选阶段设置模糊阈值进行原子的预选,删去不理想的原子;又引入一个新的标识参数,通过标识参数进行每步的可变步长操作,同时文中设计了一种幂函数型的变步长方法,以克服SAMP算法固定步长导致的重建精度问题。仿真结果表明,相比于传统的自适应重建算法,文中提出的WSStAMP算法能得到更好的信道估计性能,且算法复杂度更低。
To estimate the sparse channel in orthogonal frequency division multiplexing( OFDM) system without the prior knowledge of the sparsity of the channel,a new sparsity adaptive channel estimation algorithm is proposed,called the weak selection stagewise adaptive matching pursuit( WSStAMP) algorithm.The algorithm combines the idea of atomic preselection and variable step size,sets the fuzzy threshold for the pre-selection of atoms at the primary selection stage to delete the unsatisfactory atoms and then introduces a new identification parameter to conduct the variable step operation for each step. A variable step size method based on power function is designed to solve the reconstruction accuracy problem caused by the fixed step size of SAMP algorithm. Simulation results show that the WSStAMP algorithm has better performance on the channel estimation and lower computational complexity,compared with other traditional sparsity adaptive reconstruction algorithms.
引文
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