DFT计算常用于信号处理中求频谱值,针对利用FPGA中的NIOSU直接进行DFT计算完成速度慢和查表法占用存储资源大的问题,采用CORDIC算法提高正余弦函数及平方根运算的计算效率,进而实现DFT的快速计算。在分析DFT和CORDIC算法的基础上,重点分析CORDIC算法在正余弦函数及平方根运算中的应用方法,给出DFT计算的实现流程,并利用FPGAEP3c55F484c8N芯片予以实现。通过QuartusⅡ进行时序仿真,结果表明给出的设计方法在不占用存储资源的情况下计算精度较高,运算速度快。
DFT computing is commonly used in signal processing for the value of the frequency spec- trum, because the calculation speed of DFT is slow in NIOS II of FPGA and a large amount of memory units are necessary when the look-up table method is used, so in order to realize fast DFT, the CORDIC algorithm is used in improving the computational efficiency of the sine function, cosine function and square root. Based on the analysis of DFT and the CORDIC algorithm, the application method of CORDIC algorithm is analyzed, then the DFT calculation is exhibited and realized using FPGA architecture, results of timing simulation by Quartus II show that the method could achieve high accuracy and fast calculation speed without the use of memory resources.