What is the signal-to-noise ratio S/N, carrier C/N, and Eb/N0?

SNR (s n) is the ratio of the average power of the transmission signal to the average power of the noise.

 

Carrier voltage (C n) refers to the ratio of the average power of the modulated signal to the average power of the supplementary noise.

 

They are usually calculated in logarithm mode, in dB.

The signal-to-noise ratio differs from that of the carrier. The signal-to-noise ratio includes the power of the transmitted signal and the power of the modulated carrier. The signal-to-noise ratio only includes the power of the transmitted signal, the difference is one carrier power. Of course, the carrier power is usually very small compared with the transmission signal power, so the carrier power is very close to the signal-to-noise ratio.

 

For the modulation method of the suppression carrier, the two values are equal. The signal-to-noise ratio and the carrier-to-noise ratio can be measured directly at the receiving end.

 

In modulation transmission systems, carrier-level indicators are generally used, while in baseband transmission systems, signal-to-noise ratio indicators are generally used.

The reliability and performance of the actual digital communication system are often described by a carrier's relationship curve to the bit error rate.
The X-axis is C/N and the X-axis is Ber, as shown in. For a certain C/N, the smaller the BER, it indicates that
Higher reliability. It can be seen that the anti-interference capability of system B is better than that of system. At this time, the efficiency of system A and system B cannot be achieved.
In comparison, a may be better than B, or B may be better than. If B is better than a, the overall performance of system B is better than.
If a is better than B, it means that system B can improve anti-interference capability by sacrificing efficiency.