Quantization is a nonlinear process which generates additional frequency components (Thompson et al. 1986). This means that the signal is no longer band-limited,
so the sampling theorem no longer holds. If a
signal is sampled at the Nyquist frequency,
information will be lost. Therefore, sampling faster than the Nyquist
frequency results in detection of more of the signal and a lower signal-to-noise
ratio [SNR]. Let 
be the oversampling ratio
and define
 |
Then the following table gives values of 
for a number of parameters.
| quantization levels |  |  |
| 2 | 0.64 | 0.74 |
| 3 | 0.81 | 0.89 |
| 4 | 0.88 | 0.94 |
The Very Large Array of 27 radio telescopes in Socorro, New Mexico uses three-level quantization at 
,
so 
.
