面向 LTE 的超低复杂度 FFT 处理单元设计

摘要

In this paper,a low cost mixed -radix FFT processor is proposed based on the uplink of LTE standards.Firstly CTA and PFA are employed to factorize large length FFT to small mixed -radix FFTs.After that,WFTA is utilized to implement the mixed-radix FFTs with reusing technology.Finally,a CSD multiplier with Horner structure is employed to optimize the constant multipli-er.Compared with existing methods,the proposed method has 78.9 hardware saving in multiplier and 62.1 in total design,as well as 16.7 processing time reduction.%该文提出了一种超低复杂度的、面向长期演进（LTE）上行的快速傅里叶变换（FFT）混合基处理单元的设计与实现。由 Cooley －Tukey 算法与质因数算法，LTE 上行所需 FFT 可以分解到基2，3，5上。该文基于 Winograd 傅里叶变换设计了 FFT 处理单元，利用折叠技术对多模下 FFT 进行了算法单元复用，利用正则符号数（CSD）乘法结合树形结构与 Horner法则优化其中的乘法器结构。相比已有方法，关键路径时间降低16．7，乘法器面积降低78．9，总面积降低62．1。