energy of a signal in t and f domain
조회 수: 3 (최근 30일)
이전 댓글 표시
The energy of a signal is expected to be the same in t and f domain.
n = 1e4;
dx = 0.25;
x = rand(n,1) -0.5;
ex = sum(x.^2) *dx; % energy in t domain
y = fft(x);
fs = 1/dx;
df = fs/n;
ya = abs(y);
ey = sum(ya.^2) *df; % energy in f domain
but from the code, ey/ex=16, exactly the squared fs.
what's the problem?
댓글 수: 0
채택된 답변
Star Strider
2014년 12월 3일
You need to normalise the fft by dividing it by the length of the signal:
y = fft(x)/length(x);
See the documentation for fft for details.
추가 답변 (1개)
참고 항목
카테고리
Help Center 및 File Exchange에서 Spectral Measurements에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!