Negative Signal to Noise Ratio

A negative signal-to-noise ratio indicates that the noise power is greater than the signal power. For simple radio systems, a signal “buried in the noise” cannot be recovered, but many radio systems typically operate in this manner.

1. Can you have a negative signal to noise ratio?
2. Is positive or negative SNR better?
3. Is a positive SNR good?
4. What happens if SNR low?

Can you have a negative signal to noise ratio?

The ratio can be zero, a positive number or a negative number. A signal-to-noise ratio over 0 dB indicates that the signal level is greater than the noise level.

Is positive or negative SNR better?

As SNR is simply the ratio , and we know that ratio should be anything i.e positive or negative. But for practical case SNR should always be positive value means signal power should always be greater than the noise power. If it is negative than that system has no significance....

Is a positive SNR good?

An SNR greater than 40 dB is considered excellent, whereas a SNR below 15 dB may result in a slow, unreliable connection.

What happens if SNR low?

If the SNR value gets lower than one, the signal becomes unusable. This is called the “noise floor.” Signals close to the noise floor can be subject to data corruption, which will result in retransmissions between the transmitter and receiver.