切比雪夫多项式的数字预失真算法及其FPGA实现

摘要

In this paper, Chebyshev polynomials were drawn into the design of digital predistorters. The recursion generation character was exploited and a generation method of odd even order separation presented, which avoids high order power operations and saves resources. Simulation shows that the effects and convergence performances of Chebyshev polynomials predistorter are superior to that of common and orthogonal polynomials now available. The design is implemented in field⁃programmable gate array ( FPGA ) . Fix point simulation shows that the predistorter can effectively suppress out⁃band spectrum leakages. Its adjacent channel leakage radio( ACLR) performance is about 5~10 dB superior to that of memory polynomials.%将切比雪夫多项式引入到数字预失真器的设计中，利用其特有的递归生成特性，提出了一种奇偶阶分离的生成方法，避免了高阶幂次操作并节约了资源。仿真表明，切比雪夫多项式预失真器的效果和收敛性能均优于现有的普通以及正交多项式。在现场可编程门阵列（ field⁃programmable gate array， FPGA）上实现了设计，经过定点仿真验证，所设计的预失真器可以有效地抑制带外频谱泄漏，邻道泄漏比（ adjacent channel leakage radio， ACLR ）比普通记忆多项式有5～10 dB的提升。