What is the value of the variance of quantization error in FFT algorithm, compared to that of direct computation?
A. Greater
B. Less
C. Equal
D. Cannot be compared
Answer:A
What is the value of the variance of quantization error in FFT algorithm, compared to that of direct computation?
A. Greater B. Less C. Equal D. Cannot be compared
Explanation: If we assume that the quantization errors in each butterfly are uncorrelated with the errors in the other butterflies, then there are 4(N-1) errors that affect the output of each point of the FFT. Consequently, the variance of the quantization error due to FFT algorithm is given by