LLL格基约减中选择δ的一种方法

LLL格基约减是一种强大的格基约减算法,其可在多项式时间里输出一组近乎正交的已减格基,且已被应用于预编码领域,可在无线通信中,获得理想的分集性能。LLL格基约减算法需要人为指定参数δ。参数δ的大小决定了算法的执行时间及已减格基的好坏。在LLL格基约减算法基础上,文中提出了一种改进算法,针对特定输入矩阵H,算法自动选择δ,在执行时间和已减格基质量间达到平衡。

A Method for Choosing δ Based on the LLL Lattice Reduction Algorithm

LLL lattice reduction is a powerful algorithm which can output a group of nearly orthogonal reduced lattice basis from original basis.Recently,LLL lattice reduction has been found useful for precoding in wireless MIMO systems.There is a factor δ in LLL lattice reduction which should be specified manually.Algorithm execution time and quality of reduced lattice basis depend on the factor δ.On the base of the LLL lattice reduction algorithm,this paper propose an improved algorithm for choosing the factor δ automatically according to a specific input matrix H to meet the tradeoff between the quality of reduced lattice basis and algorithm execution time.