摘要
分析了按时间抽取(DIT)基-2快速傅里叶变换(FFT)的误差,数据格式为二进制补码.给出了蝶形运算误差分析模型,利用FFT信号流图的特点,针对截断、舍入和收敛舍入3种量化方法,得到了准确的定点和块浮点两种FFT算法的均方误差上下限.最后给出了噪信比结果,并用Matlab对其进行了仿真,结果表明,块浮点FFT算法优于定点FFT算法,舍入和收敛舍入量化方法优于截断量化方法.
The error of the decimate in time （DIT） radix-2 fast Fourier transform （FFT） is analyzed, where the data format is two＇s complement. The error analysis model of butterfly operation is given explicitly. Utilizing the characteristics of signal flow graph, for the three quantization methods of truncation, rounding and convergent rounding, the exact upper bound and lower bound of mean square error are obtained for the two FFT algorithms of fixed point and block floating point. Finally, the power ratio of noise and signal is given and the simulated results are plotted. The results show that the block floating point algorithm is better than with the fixed point algorithm. The rounding and convergent rounding quantization method is better than the method of truncation.
出处
《北京理工大学学报》
EI
CAS
CSCD
北大核心
2005年第8期739-742,共4页
Transactions of Beijing Institute of Technology
关键词
快速傅里叶变换
蝶形运算
收敛舍入
均方误差
fast Fourier transform
butterfly operation
convergent rounding
mean square error
