实序列FFT算法的存储单元图解析方法

为了正确有效地开发实序列FFT的汇编语言程序,提出了以存储单元图的方式解析实序列FFT算法的方法。首先推导了由复序列FFT的实虚部计算实序列FFT的实虚部的公式,指出了计算复序列FFT所包括的级别、蝶组、蝶形三层循环,所涉及的正弦量的计算与存储方式,以及复序列FFT转化为实序列FFT的步骤等。在此基础上利用存储单元图在TMS320C54X汇编语言环境下详细解析了实序列FFT的实虚部计算公式。设计了复序列FFT的实虚部计算的第一级、第二级、第三级到最后级的存储单元图,由复序列FFT的实虚部计算其共轭对称与反对称部分的实虚部的存储单元图,以及由此计算实序列FFT的存储单元图。CCS3.3环境下的仿真结果验证了该解析方法的正确性。

Analytical method of real sequence FFT algorithm using memory cell diagram

Based on the memory cell diagram,an analytical method is proposed to analyze the real sequence FFT algorithm and assist in effectively programming in assembly languages.First,the formulas to calculate the real and imaginary parts of real sequence FFT is introduced,which is based on the calculation of complex sequence FFT.The three loops,levels,groups and butterflies in process of computing FFT,the sinuous values and their storing way in memory,and the steps to obtain real sequence FFT from complex sequence FFT are described.Then,the real part and imaginary part formulas of real sequence FFT are analyzed in detail using the memory cell diagram under the TMS320C54X assembly language environment.The memory cell diagrams of the first level,the second level,the third level to the final level in calculations of the real part and imaginary part,memory cell diagrams of the conjugate symmetry and the antisymmetry part of complex sequence FFT,and memory cell diagrams for computing real sequence FFT are designed.Finally,the simulation under the CCS3.3 environment is presented to verify the functionality and effectiveness of the proposed method.