Iterative Signal Detection Based Soft Interference Cancellation for Satellite-Terrestrial Downlink NOMA Systems  

作　　者：Sun Meng Zhang Qi Yao Haipeng Gao Ran Xin Xiangjun Tian Feng Feng Weiying Chen Dong 

机构地区：[1]School of Electronic Engineering,Beijing University of Posts and Telecommunications(BUPT),Beijing 100876,China [2]Beijing Key Laboratory of Space-Ground Interconnection and Convergence,State Key Laboratory of Information Photonics and Optical Communications,School of Electronic Engineering,Beijing University of Posts and Telecommunications(BUPT),Beijing 100876,China [3]School of Information and Communication Engineering,Beijing University of Posts and Telecommunications(BUPT),Beijing 100876,China [4]Beijing Institute of Technology,Beijing 100081,China [5]Beihang University,Beijing 100191,China [6]China Academy of Space Technology(CAST),Beijing 100094,China

出　　处：《China Communications》2024年第8期249-263,共15页中国通信（英文版）

基　　金：supported by the National Key Research and Development Program of China(No.2021YFB2900602);the National Natural Science Foundation of China(No.61875230).

摘　　要：To improve the bit error rate(BER)performance of multi-user signal detection in satelliteterrestrial downlink non-orthogonal multiple access(NOMA)systems,an iterative signal detection algorithm based on soft interference cancellation with optimal power allocation is proposed.Given that power allocation has a significant impact on BER performance,the optimal power allocation is obtained by minimizing the average BER of NOMA users.According to the allocated powers,successive interference cancellation(SIC)between NOMA users is performed in descending power order.For each user,an iterative soft interference cancellation is performed,and soft symbol probabilities are calculated for soft decision.To improve detection accuracy and without increasing the complexity,the aforementioned algorithm is optimized by adding minimum mean square error(MMSE)signal estimation before detection,and in each iteration soft symbol probabilities are utilized for soft-decision of the current user and also for the update of soft interference of the previous user.Simulation results illustrate that the optimized algorithm i.e.MMSE-IDBSIC significantly outperforms joint multi-user detection and SIC detection by 7.57dB and 8.03dB in terms of BER performance.

关 键 词：non-orthogonal multiple access(NOMA) resource allocation satellite-terrestrial communication signal detection soft interference cancellation 

分 类 号：TN927.2[电子电信—通信与信息系统]