Signal-to-Noise Ratio (SNR) is a measure of how strong a signal is compared to the background noise in a communication system. It is typically expressed in decibels (dB). The higher the SNR, the clearer and more reliable the signal.
I often get asked, how is signal to noise calculated. Frankly the math is not hard. Here it is:
SNR Formula:
Where:
- Psignal is the power of the signal.
- Pnoise is the power of the noise.
In decibels (dB), SNR is expressed as:
Example 1: Basic SNR Calculation
Let’s say the signal power is 100 mW (milliwatts) and the noise power is 1 mW. Using the SNR formula:
So, the SNR in this example is 20 dB, indicating a strong signal compared to the noise.
Example 2: Lower Signal, Higher Noise
Suppose the signal power is reduced to 10 mW, and the noise power increases to 2 mW. The new SNR calculation would be:
Here, the SNR is about 7 dB, which indicates a weaker signal relative to the noise, meaning the quality of the communication would be less reliable than in the first example.
Example 3: Converting SNR from dB to Power Ratio
If you have an SNR of 30 dB and want to convert it back to a power ratio:
This means the signal is 1000 times stronger than the noise.
Importance in Wi-Fi Networks
In Wi-Fi networks, the SNR is crucial for determining the quality of a wireless connection. Typically:
- SNR of 20 dB or higher is considered good for a stable connection.
- SNR below 10 dB might result in poor performance, frequent disconnections, and lower data rates.
By maintaining a high SNR, Wi-Fi networks can ensure reliable communication and higher data throughput.
Comments are welcomed below from registered users. You can also leave comments at our Discord server.
If you would like to see more content and articles like this, please support us by clicking the patron link where you will receive free bonus access to courses and more, or simply buying us a cup of coffee!