EE5410 Signal processing : The relationship between xd[n] and xc(t)
1. any discrete-time Fourier transform is periodic in Omega with period 2PI.
2. The spectrum of xd[n] is related to that of xc(t) through periodic replication , followed by linear frequency.
3. The periodic replication is a consequence of the first step in the conversion process, namely, the impulse-train sampling.
4. The linear frequency scaling can be thought of informally as a consequence of the normalization in time introduced by converting from the impulse train xp(t) to the discrete-time sequence xd[n].
5. From the time-scaling property of the Fourier transform, scaling of the time axis by 1/T will introduce a scaling of the frequency axis by T.
6. Thus, the relationship Omega = wT is consistent with the notion that, in converting from xp(t) to xd[n], the time axis is scaled by 1/T.
Can Dialectics Break Bricks? (1973) (主演 : 陳鴻烈) Situationist 惡搞整部電影