高动态条件下的星地两步随机接入增强方法设计  

Design of an Enhanced Two-step Satellite-Ground Random AccessMethod Under High Dynamic Conditions

作　　者：赖禹新 李序 杨涛 刘荣科[1,2] LAI Yuxin;LI Xu;YANG Tao;LIU Rongke(School of Electronic and Information Engineering,Beihang University,Beijing 100191,China;Shenzhen Beihang Emerging Industry Technology Research Institute,Shenzhen 518063,China)

机构地区：[1]北京航空航天大学电子信息工程学院,北京100191 [2]深圳北航新兴产业技术研究院,广东深圳518063

出　　处：《无线电通信技术》2024年第6期1101-1109,共9页Radio Communications Technology

基　　金：国家重点研发计划(2022YFB2902604);深圳市科技计划(KJZD20230928112759002);国家自然科学基金(62371020);北京市自然科学基金(L232044)。

摘　　要：低轨卫星具有空间衰减强、移动速度快、覆盖范围广的特点。针对星地随机接入速度慢、容量小、受多普勒频移影响严重的问题,设计了一种高动态条件下的星地两步随机接入增强方法。通过对用户上行MsgA数据进行若干次重复并在接收端引入干扰消除技术进行解调,从而利用碰撞数据减少用户重发概率,解决了星地随机接入速度与容量的问题;通过引入双根前导码并在接收端进行联合检测,解决了高动态下随机接入前导检测成功率低的问题。相比传统的随机接入方案,实现了更高的接入速度和接入容量。The low earth orbit satellite features strong space attenuation,rapid movement,and extensive coverage.To address the issues of low velocity and low capacity of satellite-ground random access,as well as the severe impacts from Doppler frequency shifts,this paper proposes an enhanced two-step satellite-ground random access method under high dynamic conditions.On the one hand,by repeating the user’s uplink MsgA data multiple times and incorporating successive interference cancellation at the receiver for demodulation,this method allows for the utilization of collided data and reduces the probability of user retransmissions,thus increasing the velocity and capacity of the random access process.On the other hand,by introducing two-root preambles and performing joint detection at the receiver,this method tackles the problem of low preamble detection success rates under high dynamic conditions.Ultimately,compared to traditional random access schemes,the proposed method achieves faster access velocity and higher access capacity.

关 键 词：低轨卫星通信 随机接入 不规则重复时隙ALOHA 双根前导码 

分 类 号：TN927.23[电子电信—通信与信息系统]