Abstract

Background: External noise is a necessary factor for calculating the signal-to-noise ratio and evaluating communication quality and is one of the important parameters when designing low-frequency communication schemes or evaluating low-frequency signal quality.

Methods: To study the radio noise distribution of each frequency point within the low-frequency band from 40kHz to 80kHz in a typical Southern China region at different time periods, the test team conducted a low-frequency radio noise test in Ziyang District, Yiyang City.

Results and Discussion: The test data is analyzed and the results show that in this area, the radio noise in the 40kHz to 80kHz frequency band changes significantly day and night. The noise factors of most frequency points are in line with the predicted value given in the predicted value of the Radio Noise Volume of Recommendation ITU-R P.372-10.

Conclusion: However, the noise distributions of 50kHz, 54kHz, 60kHz, and 68.5kHz are significantly higher than those of the predicted values.

Keywords: External noise, low-frequency signal measurement technology, radio noise, noise measurement, noise prediction, ITU-R.