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China Communications 2024年第8期21卷 236-248页

作者： Xu Yuanyuan Liu Ziwei bian dongming Zhang Gengxin School of Communications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China Institute of Communications Engineering PLA University of Science and TechnologyNanjing 210007China

There are numerous terminals in the satellite Internet of Things(IoT).To save cost and reduce power consumption,the system needs terminals to catch the characteristics of low power consumption and light *** regular random access(RA)protocols may generate large amounts of collisions,which degrade the system throughout *** near-far effect and power control technologies are not applicable in capture effect to obtain power difference,resulting in the collisions that cannot be *** fact,the optimal design at the receiving end can also realize the condition of packet power domain separation,but there are few relevant *** this paper,an auxiliary beamforming scheme is proposed for power domain signal *** adds an auxiliary reception beam based on the conventional beam,utilizing the correlation of packets in time-frequency domain between the main and auxiliary beam to complete signal *** roll-off belt of auxiliary beam is used to create the carrier-to-noise ratio(CNR)*** paper uses the genetic algorithm to optimize the auxiliary beam *** results show that the proposed scheme outperforms slotted ALOHA(SA)in terms of system throughput per-formance and without bringing terminals additional control burden.

关键词： beamforming non-orthogonal multiple access random access satellite Internet of Things

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基于多特征融合的卫星信号调制方式识别

信号处理 2024年第7期40卷 1298-1306页

作者：李云涛边东明张更新南京邮电大学通信与信息工程学院江苏南京210003 陆军工程大学通信工程学院江苏南京210000

面向卫星通信中常用的QPSK类调制方式识别问题,提出了一种联合了谱特征、瞬时统计特征、高阶累积量特征和幅度分布特征的调制识别算法。算法在信号预处理与频域检测的基础上,首先利用速率信号谱特征和二次方谱特征识别出OQPSK和BPSK,然... 详细信息

面向卫星通信中常用的QPSK类调制方式识别问题,提出了一种联合了谱特征、瞬时统计特征、高阶累积量特征和幅度分布特征的调制识别算法。算法在信号预处理与频域检测的基础上,首先利用速率信号谱特征和二次方谱特征识别出OQPSK和BPSK,然后分别利用频谱重心法和速率信号法估计信号的载频、带宽和符号速率等参数,并从正交下变频及匹配滤波后的符号定时同步后的复信号中提取高阶累积量特征参数,将剩余信号分类为调相信号和幅相调制信号,最后联合四次方谱特征和幅度分布特征完成所有调制方式的识别。仿真结果表明算法对频偏不敏感,于16APSK和32QAM的识别性能也比传统的基于高阶谱的方法要好,且算法在信噪比为6 dB时除16QAM和64QAM外的调制方式识别率为100%。最后,用信号源和采集卡搭建测试平台,九种实采信号的分类结果验证了算法的有效性,由于经频谱重心法估计出的载频存在一定误差,再次证明了该算法对频偏不敏感。

关键词：卫星通信谱特征瞬时特征参数高阶累积量调制信号识别

A SURVEY OF DEEP SPACE COMMUNICATIONS

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Journal of Electronics(China) 2011年第2期28卷 145-153页

作者： Zhang Gengxin Xie Zhidong bian dongming Sun Qian Institute of Communication Engineering PLA University of Science and Technology Nanjing 210007 China

Deep space communications has played an important role in deep space exploration. Compared with common satellite and terrestrial communications, deep space communications faces more challenging environment. The paper investigated the unique features of deep space communica-tions in detail, discussed the key technologies and its development trends for deep space communica-tions.

关键词： Deep space communication Modulation Channel coding Protocol Networking

BLIND SYMBOL RATE ESTIMATION OF SATELLITE COMMUNICATION SIGNAL BY HAAR WAVELET TRANSFORM

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Journal of Electronics(China) 2011年第2期28卷 198-203页

作者： Wang Long Zhang Gengxin bian dongming Xie Zhidong Hu Jing Institute of Communication Engineering PLA UST Nanjing 210007 China

As the raised cosine shaping filter is often employed in practical satellite communication system,the envelope fluctuation at the symbol transition point is decreased which leads to the failure of the common wavelet algorithm under low ***,a method of blind symbol rate estimation using signal preprocessing and Haar wavelet is proposed in this ***,the effect of filter shaping can be reduced by the signal ***,the optimal scale factor is searched and the signal is processed and analyzed by the Haar wavelet ***,the symbol rate line is extracted and a nonlinear filter method is inducted for improving the estimation *** analysis and computer simulation show the efficiency of the proposed algorithm under low SNR and small roll-off factor.

关键词： Haar wavelet Symbol rate Preprocessing Blind estimation

A NOVEL MODULATION FOR MOBILE SATELLITE COMMUNICATIONS

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Journal of Electronics(China) 2011年第2期28卷 174-180页

作者： Xie Zhidong bian dongming Hu Jing Sun Qian Institute of Communication Engineering PLA University of Science and Technology Nanjing 210007 China

It is a challenging problem to design a high performance modulation for mobile satellite communications due to the limited power and bandwidth *** paper improves Feher patented Quadrature Phase Shift Keying(FQPSK) by redefining the *** novel FQPSK,with con-stant envelope,can be used to improve the power efficiency and frequency efficiency of mobile satellite *** study shows that the improved FQPSK outperforms conventional FQPSK over AWGN and is immune to the non-linearity of high power *** last,the impact of flat fading and multi-path fading of channel on the BER performance of improved modulation is analyzed.

关键词： Mobile satellite communication Modulation Feher Quadrature Phase Shift Keying(FQPSK) Fading

Modeling the RTT of bundle protocol over asymmetric deep-space channels

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Journal of Communications and Information Networks 2016年第3期1卷 97-104页

作者： bian Zhengguo ZHANG Gengxin bian dongming College of Communication Engineering PLA University of Science and TechnologyNanjing 210007China

Delay/disruption-tolerant networking communications rely heavily on BP(Bundle Protocol),which uses the well-known approach of store-and-forward with optional custody transfer to deal with stressed communication *** use of BP and its performance in deep-space communication has been the subject of *** accurate estimate of file delivery latency(i.e.,RTT(Round Trip Time))is essential for efficient transmission control,reliable delivery,and bandwidth usage optimization of a *** this paper,we present a performance analysis of BP running over UDPCL/UDP over deep-space channels,focusing on the RTT estimate,in the presence of highly asymmetric channel *** models are built for the RTT estimate of the BP/UDPCL transmissions considering the effect of delay caused by space channel-rate asymmetry,and,channel *** models are validated by file transfer experiments using a PC-based *** is found that a smaller bundle size(if smaller than a calculated threshold)results in a longer delay in custody acknowledgment transmission,and thus,a longer RTT.

关键词： deep-space communications delay/disruption-tolerant networking bundle protocol

Cluster-based architecture and network model for InterPlaNetary Internet

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Journal of Communications and Information Networks 2016年第3期1卷 51-66页

作者： GOU Liang ZHANG Gengxin ZHANG Wei bian dongming College of Communication Engineering PLA University of Science and TechnologyNanjing 210007China No.96275 of People's Liberation Army of China Luoyang 471003China

Along with the development of the IPN(InterPlaNetary)Internet,the terrestrial Internet and interplanetary exploration network will be seamlessly merged with each ***,significant challenges in control and management exist in such a complicated *** include the efficient and reliable dissemination of control information,and the building up of an overlay *** paper reviews current networking technologies for the IPN Internet and presents a novel architecture that divides it into subnets.A network model based on clusters is proposed to account for the problem of dynamic coupling among subnets and achieve monolithic controllability of the whole network.A new paradigm that separates the control and service planes is presented to reduce congestion and guarantee the reliable distribution of control *** also present a modified version of a delay-tolerant-network protocol stack that separates the network layer into generalized inter-cluster sub-layers and discriminative intra-cluster sub-layers to improve the transmission efficiency of control *** results indicate that both the control and service data delivery is more efficient and reliable through clustering of the IPN ***,we present recent achievements in network-information theoretical approaches that can be successfully applied to deep-space communication.

关键词： InterPlaNetary Internet architecture network model cluster protocol

A hierarchical autonomous system based space information network architecture and topology control

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Journal of Communications and Information Networks 2016年第3期1卷 77-89页

作者： ZHANG Wei ZHANG Gengxin XIE Zhidong bian dongming LI Yongqiang College of Communication Engineering PLA University of Science and TechnologyNanjing 210007China Department of Optical and Electrical Equipment Equipment AcademyBeijing 101416China

SIN(Space Information Network)has recently emerged as a promising approach to solving the collaboration difficulty among current space ***,because of the SIN’s large scale,high component complexity,and dynamic characteristics,designing a proper SIN architecture is ***,we propose a novel SIN architecture,which is composed of GEO(Geostationary Earth Orbit)satellites as backbone network nodes,LEO(Low Earth Orbit)or other types of satellites as enhanced coverage nodes,and high-altitude platforms to meet the service requirements of emergency or hot-spot *** most existing studies,the proposed architecture is AS(Autonomous-System)*** decouple the complex SIN into simpler sub-networks using a hierarchical AS ***,we propose a topology control algorithm to minimize the time delay among sub-AS *** prove that the proposed algorithm achieves logical k-connectivity provided that the original physical topology has *** results validate the theoretic analysis and effectiveness of the algorithm.

关键词： space information network architecture autonomous system topology control time delay strong connectivity

A New Approach for Carrier Frequency Offset Estimation in OFDM Communication System

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A New Approach for Carrier Frequency Offset Estimation in OF...

Blind Channel Estimation Algorithm of Uplink for MC-CDMA System

2003 International Conference on Communication Technology

作者： bian dongming Department of communication and engineering PLAUniversity of information and technology Zhengzhou China Yi Xinying Department of military simulation PLAUniversity of science and technology Nanjing China

In this paper, we propose a new time-domain estimator for OFDM signal by using over-sample technology. The proposed estimator is able to achieve wider estimation range of carrier frequency offset with

关键词： OFDM carrier frequency offset estimation carrier synchronization

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Blind Channel Estimation Algorithm of Uplink for MC-CDMA Sys...