一种卫星物联网异步信号接收方法研究  

Research on Asynchronous Signal Receiving Method of Satellite Internet of Things

作　　者：李冉冉 刘子威 张更新 LI Ranran;LIU Ziwei;ZHANG Gengxin(School of Communication and Information Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210003,China)

机构地区：[1]南京邮电大学通信与信息工程学院,江苏南京210003

出　　处：《无线电工程》2024年第12期2872-2879,共8页Radio Engineering

基　　金：国家自然科学基金(62171234,61971440,62271266)。

摘　　要：低轨卫星物联网因广覆盖的特点,受到了广泛的关注和研究。然而,目前卫星物联网中的同步随机接入体制存在终端与卫星信令交互多、时延大的问题,无法满足卫星物联网终端对低功耗、轻控制的要求。针对低轨卫星物联网异步随机接入信号的特点,引入恒虚警检测技术对异步随机接入信号进行捕获;利用捕获结果,构建信号间的相对位置矢量(Relative Position Vector, RPV)对异步随机接入信号进行碰撞识别,并对无碰撞的异步随机接入信号进行解调;在正确解调的基础上,引入信号分离技术,设计了异步随机接入信号解调与分离流程,从而实现异步随机接入信号的高效接入,并对所提方案进行吞吐量仿真。仿真结果表明,所提方案可以实现异步随机接入信号的捕获、碰撞识别、解调与信号分离。相比于传统接收方案,所提方案在信道处于中高负载时可以实现对未知碰撞的异步随机接入信号的捕获,并在此基础上实现碰撞识别、解调与信号分离,同时吞吐量损失在可接受范围之内,可以支持低轨卫星对异步随机接入信号的高效接收,具有一定的实用性。The low earth orbit satellite Internet of things has received extensive attention and research due to its wide coverage.However,the current synchronous random access system in the satellite Internet of things has the problems of more interaction between terminals and satellite signaling and large delay,which can not meet the requirements of low power consumption and light control of Satellite Internet of things terminals.According to the characteristics of the asynchronous random access signal of LEO Satellite Internet of things,the constant false alarm detection technology is introduced to capture the asynchronous random access signal;Using the acquisition results,the relative position vector between signals is constructed to identify the collision of asynchronous random access signals,and the collision free asynchronous random access signals are demodulated;On the basis of correct demodulation,the signal separation technology is introduced,and the demodulation and separation process of asynchronous random access signal is designed,so as to realize the efficient access of asynchronous random access signal,and the throughput of the proposed scheme is simulated.Simulation results show that the proposed scheme can realize the acquisition,collision recognition,demodulation and signal separation of asynchronous random access signals.Compared with the traditional receiving scheme,the proposed scheme can capture the asynchronous random access signal with unknown collision when the channel is under medium and high load,and realize collision identification,demodulation and signal separation on this basis.At the same time,the throughput loss is within the acceptable range,which can support the efficient reception of asynchronous random access signal by LEO satellites,and has certain practicability.

关 键 词：卫星物联网 随机接入 海量连接 信号分离 

分 类 号：TN927.2[电子电信—通信与信息系统]