Research On Multi-user Detection Algorithm For High-throughput Satellite Communication System

Satellite communication is an indispensable part of the future world-wide integrated network.It is developing towards higher speeds and higher system throughput,and high-throughput satellite systems have emerged.High-throughput satellite systems mainly use multi-beam technology and frequency reuse technology,which is an order of magnitude higher than traditional communication satellite system throughput.While the throughput of high-throughput satellite systems has increased,it has also caused serious co-channel interference problems between adjacent beams.Therefore,this paper will focus on the suppression of co-channel interference in high-throughput satellite systems.This paper first studies the structure of high-throughput satellite systems,and on this basis,analyzes the mechanism of severe co-channel interference in high-throughput satellite systems.Subsequently,for the co-channel interference problem of the high-throughput satellite system reverse link,this paper considers the multi-user detection algorithm for suppression.There are many kinds of multi-user detection algorithms and the gap is large.This paper starts from the aspects of algorithm error bit rate and implementation complexity.Through theoretical analysis and experimental simulation,the related multi-user detection algorithm is discussed.The main research results are as follows:High-throughput satellites generally use higher frequencies such as Ka,which are subject to more severe rainfall attenuation.This paper first establishes a high-throughput satellite reverse link channel model including atmospheric factors,and considers the use of multi-user detection techniques in high-throughput satellite reverse links,using this technique to process received signals at the receiving end.The purpose of suppressing co-channel interference is achieved.This paper considers linear multiuser detection algorithm and nonlinear multiuser detection algorithm.Aiming at the problem that the complex multi-user detection algorithm requires complex inversion matrix,this paper considers introducing a mathematical method,and expects to obtain the inverse matrix in the case of lower complexity,and to ensure that the bit error rate is not significantly reduced.In high-throughput satellite communication systems,user interference is related to the location of the user in the beam.When the number of co-channel interference users increases,the typical multi-user detection algorithm cannot distinguish multiple user signals,and the receiving end cannot decode normally.Therefore,this paper will also explore search-based multi-user detection algorithms.Taking the result of the linear detection algorithm as the initial value and searching for the better vector in its adjacent vector,the error performance is further reduced,but the computational complexity is relatively high.Consider reducing the neighborhood algorithm and neighborhood selection rules to find more vectors within the scope of smaller searches,thus reducing the complexity of the search algorithm.On the basis of reducing the complexity of the search algorithm,a search multi-user detection algorithm not limited to the fixed search domain is proposed to obtain better error performance.