Self-adaptive coding modulation beam switching method for mobile broadband satellite communication system applied to high-speed railway

Abstract

The invention discloses a self-adaptive modulation coding beam switching method for a mobile broadband satellite communication system applied to a high-speed railway. The method includes the steps that A, reference threshold values, corresponding to all self-adaptive modulation coding modes, of the signal to noise ratio are determined, according to the channel state information-the receiving signal to noise ratio of the current mobile broadband satellite channel, errors between the value of the receiving signal to noise ratio and the reference threshold values, corresponding to the self-adaptive modulation coding modes, of the signal to noise ratio are calculated, according to the sizes of the errors, the value of the average signal to noise ratio at the receiving end is corrected at different degrees, and the corresponding modulation coding mode is determined according to the size of the average signal to noise ratio obtained through correction; B, if the value of the average signal to noise ratio obtained through correction is smaller than the reference threshold value, corresponding to the lowest-order modulation coding mode, of the signal to noise ratio, a beam is switched. Under the high-speed railway mobile broadband satellite communication environment with fixed lines, the transmission performance of the system is effectively improved, the error rate performance of the system is ensured, and the handling capacity of the system is improved; beam resources are fully used, and frequent and unnecessary beam switching is avoided.

Description

technical field [0001] The invention relates to the field of satellite communication. In particular, it relates to a method for determining an adaptive coding and modulation mode and a method for switching mobility beams by using adaptive coding and modulation in a mobile broadband satellite communication system applied to high-speed railways. Background technique [0002] my country has the largest high-speed railway network in the world, and the operating mileage of high-speed railway accounts for about 46% of the operating mileage of high-speed railway in the world. High-speed rail has the characteristics of wide distribution of mobile users, fast moving speed, and certain regularity in moving paths. The mobile broadband satellite communication system is used to provide broadband communication services for high-speed rail users. It has the advantages of large beam coverage, fast construction speed, saving ground resources, and easy Advantages such as broadcast and multip...

AI Technical Summary

Problems solved by technology

Although this method is simple and easy to implement, there will be problems such as geographic positioning errors and premature beam switching.

At the same time, only the geographical location is used as the beam switching condition, which cannot make full use of the channel resources under the beam, which reduces the resource utilization rate.

In order to avoid the above problems, this patent proposes a beam switching method using adaptive modulation and coding technology for mobile broadband satellite communication systems applied to high-speed railways, so as to solve the problem of inaccurate beam switching and excessive beam switching caused by positioning errors. early question

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