一种基于差分的改进STAM算法

STAM算法是硬件实现非线性函数的一种有效方法，它用查找表和加法运算实现了精确的非线性函数近似，并利用函数的对称性极大地缩减了查找表的尺寸，但算法中第一项系数占用的查找表仍然较大。针对此问题，提出了一种基于差分的改进方法，并在FPGA上实现了双曲正切S形函数。实验结果显示，算法经过改进可以缩减17%~30%的存储空间。

Improved STAM Algorithm Based on Differential Method

STAM algorithm is an efficient approach to implement non-linear function approximation with hardware, in which lookup tables and addition arc involved to approximate non-linear function accurately, and size of table could be reduced remarkably due to symmetry of function. Nevertheless the first coefficient still uses relatively big table. An improved method based on differential was brought up aiming at relieve the problem, and with the algorithm hyperbolic tangent sigmoid function was implemented on FPGA. Experimental results show that 17 0 0 to 30 0 0 of memory was saved after improvement.