Help me troubleshoot signal aliasing problem

[scdoro]

hi everyone,

can someone help me to troubleshoot this question?
********************************************
i drew the graph for the analog signal.its a triangular waveform with freq,f1=1hz.
The signal is sampled at fs=8hz and reconstructed using ideal reconstructor.

what i did was:
baseband aliased freq=[-4,4].
The freq of the signal has only 1 freq component f1=1hz.
Since f1 falls within the nyquist interval, so it is not aliased.

after this, we assume there is no prefiltering and we just use the ideal reconstructor, how can we show that the reconstructed analog signal is a summation of 2 sine wave?

please enlighten

(see attachment for full question)

thanks

regards
scdoro

 

[zox11]

Re: aliasing problem

You should consider the Fourier transform of a signal, not a signal in a time domain, and find out what is the highest frequency. So, what is the highest frequency?? It is the answer to your question.

The highest frequency of signal is f1

The sampling frequency is f2

So , f2=2 f1.

But ,f1 is not 1Hz. I did find the F. transform , but I think f1 =+∞.
Therefore, we have a aliasing.