| 5 | NOMA-Based Collaborative Beam Hopping Frequency Allocation Mechanism for Future LEO Satellite Systems显示文摘Low Earth orbit(LEO) satellite systems provide terrestrial users with services that are not limited by geographical location. However, the conflict between existing allocation schemes and the business variability between beams is becoming increasingly prominent. Beam hopping technology allows for a more flexible and versatile approach to satellite resource allocation. This paper proposes a beam hopping pattern optimization scheme that jointly considers the interference threshold distance and beam service priority, reducing the inter-beam co-channel interference(CCI). In the cluster area, a non-orthogonal multiple access(NOMA)-based collaborative beam hopping(NCBH) scheme is proposed to minimize the cell-edge user(CEU) interference. Since there is a difference in channel gain between the CEU and cellcenter user(CCU), this scheme forms a NOMA cluster to perform power domain multiplexing and formulates a NOMA cluster pairing strategy according to the user location to reduce the CCI of the CEU. After NOMA cluster pairing, the optimal carrier frequency of the NOMA cluster is selected by a reinforcement learning algorithm. The simulation results verify the excellent performance of the proposed NCBH scheme regarding the user’s received power, transmission rate, and outage probability. | Fei Zheng Zhao Pi Zou Zhou Miao Ye Hongbing Qiu | 2023 | China Communications2023，20，6： | 0 |
| 6 | Revisiting the contribution of Fe^(Ⅳ)O^(2+)in Fe(Ⅱ)/peroxydisulfate system显示文摘Recent studies have proposed that the high-valent iron species(such as Fe^(Ⅳ)O^(2+))rather than sulfate radical(SO_(4)^(·-))and hydroxyl radical(·OH)are the main reactive oxidant species(ROS)in Fe(Ⅱ)/peroxydisulfate(PDS)system with the methyl phenyl sulfoxide(PMSO)as the Fe^(Ⅳ)O^(2+)probe.However,many operational factors may interfere with the accuracy of this method,so the contribution of Fe^(Ⅳ)O^(2+)calculated by this method is controversial.In this study,the possible effect of Fe(Ⅱ)concentration,pollutant type,reducing agent,or coexisted anions on Fe^(Ⅳ)O^(2+)production and its corresponding contribution to the removal of target pollutants in the Fe(Ⅱ)/PDS system were investigated in detail,and the intrinsic mechanisms involved were also explored.This study shows that ROS generation is a complex process in the Fe(Ⅱ)/PDS system,and multiple combinatorial approaches are urgently required to deeply explore the contribution of ROS to the elimination of target contaminants. | Kunjie Hou Peng Shen Zhu Wang Zhoujie Pi Fei Chen Xiaoming Li Haoran Dong Qi Yang | 2023 | Chinese Chemical Letters2023，34，3： | 0 |
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