What are the advantages and disadvantages of sampling a signal?

Answer 1

Sampling a signal is a process where some thing, usually an analog signal, is sampled at a particular frequency, and analysis and processing is performed on that sample stream. The advantages are that conversion between the time domain and the frequency domain using Fourier analysis is a very powerful technique that allows you to do a lot of different things, such as compression and filtering, without needing advanced electronics. You can also transmit the digital samples from one point to another, using digital electronics, rather than analog electronics. Disadvantages are that sampling, by its very nature, introduces distortion, because you have limited resolution on the ADC and you have limited frequency of sample rate. Often, however, you can do very well, so long as you understand the implications of sampling. One of them is called Nyquist Aliasing. That is where the sample rate is less than the Nyquist frequency of one half of the highest harmonic of the signal. This is a very noticeable distortion, perceived as a buzzing in inverse frequency terms, which must be properly filtered. In fact, if you look at a traditional audio CD, the sample rate is 44.1 KHz, making the Nyquist frequency 22.05 Khz. That is commonly above the range of human hearing, but you still must account for it, otherwise, the distortion could damage the equipment or degrade the signal quality.