It is said in the books that increasing the levels of quantisation codes in Pulse Code Modulation, or in other words increase the number of bits, could give a better signal.
I understand that having a higher number of bits can represent a value closer to the voltage of the original signal sent out. However, I don't understand how by just increasing the levels could give a better signal if the sampling rate remains constant.
I have a feeling that the sampling rate would affect more on the quality of the signal than increasing the number of levels or bits. Higher sampling rate takes more samples from the original signal to form another signal closer to it.
It's like so what if I had 64 bits if my sampling rate isn't high enough. Then increasing the number of bits will not affect anything to the sampled signal, will it? Is there a relationship between the sampling rate and the number of levels/bits during PCM quantisation that at one point, increasing either one of them(sampling rate or levels) will not do any difference until the other is being increased?