Satellite Adaptive Coding and Modulation Method Based on Channel Quality Prediction

Abstract

The invention provides a satellite adaptive coding and modulation method based on channel quality prediction. Firstly, the satellite terminal uses the signal-to-noise ratio feedback result combined with the LMS algorithm to periodically complete the prediction of the channel signal-to-noise ratio; The predicted value of the noise ratio replaces the feedback value for ACM transmission of DVB‑S2X; when the predicted values ​​of n times of SNR fall into the range of ‑5 to 5dB, the optimized subset ACM adjustment is performed; when the predicted values ​​of SNR of m times in a row If the values ​​fall out of the ‑5 to 5dB region, exit the optimized subset ACM and return to the ACM in traditional DVB‑S2X. The present invention overcomes the time delay problem of the feedback link, effectively reduces the frequency of feedback through channel prediction, and also avoids the problem of ACM mismatch caused by poor feedback link quality or large time delay. Can quickly switch to the corresponding modulation code.

Description

technical field [0001] The invention relates to a satellite code modulation method. Background technique [0002] Satellite communication has become an indispensable part of people's life, scientific research, military and other fields. Especially in war, effective and reliable battlefield communication is an important guarantee for the final victory. Complicated electromagnetic environments and adaptive coding and modulation technology have higher spectrum resource utilization than fixed coding and modulation technology, but this improvement in utilization is based on the premise of accurate, reliable and timely feedback information. The frequency band allocated by ITU for satellite fixed communication is the Ka frequency band, which has 3.5GHz frequency band resources and can provide more communication capacity. However, since the Ka frequency band is greatly affected by rain attenuation, the instantaneous fading caused by rainfall on the Ka frequency band can reach up to...

AI Technical Summary

Problems solved by technology

In addition, as the granularity of the adaptive coding and modulation technology (ACM) of the latest satellite standard DVB-S2X becomes more and more refined, when the rain attenuation is large, the feedback frequency required by the adaptive coding and modulation technology is higher, and the feedback delay the greater the impact

If the channel information cannot be fed back in time, the satellite end will adopt a non-optimal coding and modulation method, resulting in a high bit error rate and a decrease in throughput.

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