You are talking about DFT for digital signals. In this case, the first thing is the sameples you take from analog signals. If the samples taken is not periodic, it will make "frequency leaking" when applying DFT. In the case the number samples is the a common multiplier of two individual input sequences, you will see clearly two spikes on spectrum.
我使用这个来计算spectrum。 s = 20 * log10(abs(fft(y)/N/afs*2)); N是采样数,afs 是振幅。 是对的吧? 谢谢
【在 z*****n 的大作中提到】 : You are talking about DFT for digital signals. : In this case, the first thing is the sameples : you take from analog signals. If the samples taken : is not periodic, it will make "frequency leaking" : when applying DFT. : In the case the number samples is the a common : multiplier of two individual input sequences, : you will see clearly two spikes on spectrum.