基于高斯近似的异步非正交多址接入多用户检测算法  

Multi-User Detection Algorithm for Asynchronous Non-Orthogonal Multiple Access Based on Gaussian Approximation

作　　者：王培森 王悦能 程波铭 杨悦 叶能[3] WANG Peisen;WANG Yueneng;CHENG Boming;YANG Yue;YE Neng(School of Information and Electronics,Beijing Institute of Technology,Beijing100081,China;Ruixin Academy of Classic Learning,Beijing Institute of Technology,Beijing 100081,China;School of Cyberspace Science and Technology,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学信息与电子学院,北京100081 [2]北京理工大学睿信书院,北京100081 [3]北京理工大学网络空间安全学院,北京100081

出　　处：《天地一体化信息网络》2023年第1期73-81,共9页Space-Integrated-Ground Information Networks

基　　金：国家自然科学基金资助项目(No.62101048,No.62071038,No.61971038)。

摘　　要：码域非正交多址接入(NOMA)技术是卫星互联网实现泛在互联接入的潜在技术之一。考虑到星地传输具有大传播时延、高信道动态等特点,地面接入设备间保持严格定时同步将导致难以忍受的时间资源开销。多用户需要在松弛的同步关系下实现接入。现有码域NOMA的多用户检测算法大多基于同步传输假设,无法准确建模并高效缓解异步多用户传输引入的复杂干扰。为此,将用户间的相对时延引入传统的二部因子图中构建一种新颖的多层因子图模型,并基于此提出一种基于高斯近似的低复杂度异步多用户检测算法。该算法在每个用户的估计之间进行迭代,并在用户之间传播估计信息改进近似。仿真结果表明,在高信噪比区域,所提出检测算法性能优于同步NOMA的类似算法。Code domain non-orthogonal multiple access(NOMA)is one of the potential technologies to realize ubiquitous access in the future satellite internet.Considering that satellite-to-ground transmission has the characteristics of large propagation delay and high channel dynamics,strict timing synchronization between ground devices will lead to unbearable time resource overhead.Loosed synchronization relationship are required to achieve multi-user access in satellite internet.However,most of the existing multi-user detection algorithms in code domain NOMA are based on the assumption of synchronous transmission,which cannot accurately model and eff ectively alleviate the complex interference introduced by asynchronous multi-user transmission.Therefore,a novel multi-layer factor graph model by introduced the relative delay among users into the traditional two-part factor graph was constructed,and a low-complexity asynchronous multi-user detection algorithm based on gaussian approximation was proposed.The proposed algorithm iterated between each user's estimates and propagated the estimated information between users to improved the approximation.Simulation results showed that in high SNR region,the performance of the asynchronous code-domain NOMA with the proposed algorithm even outperforms its synchronous counterpart.

关 键 词：非正交多址接入 异步 多用户检测 消息传递算法 

分 类 号：V19[航空宇航科学与技术—人机与环境工程]