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A Support Data-Based Core-Set Selection Method for Signal Recognition

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China Communications 2024年第4期21卷 151-162页

作者： Yang Ying zhu lidong Cao Changjie National Key Laboratory of Wireless Communications(University of Electronic Science and Technology of China) Chengdu 611731China College of Computer Science and Cyber Security(Chengdu University of Technology) Chengdu 610059China College of Mathmatics and Physics(Chengdu University of Technology) Chengdu 610059China

In recent years,deep learning-based signal recognition technology has gained attention and emerged as an important approach for safeguarding the electromagnetic ***,training deep learning-based classifiers on large signal datasets with redundant samples requires significant memory and high *** paper proposes a support databased core-set selection method(SD)for signal recognition,aiming to screen a representative subset that approximates the large signal ***,this subset can be identified by employing the labeled information during the early stages of model training,as some training samples are labeled as supporting data *** support data is crucial for model training and can be found using a border sample *** results demonstrate that the SD method minimizes the impact on model recognition performance while reducing the dataset size,and outperforms five other state-of-the-art core-set selection methods when the fraction of training sample kept is less than or equal to 0.3 on the RML2016.04C dataset or 0.5 on the RML22 *** SD method is particularly helpful for signal recognition tasks with limited memory and computing resources.

关键词： core-set selection deep learning model training signal recognition support data

For LEO Satellite Networks: Intelligent Interference Sensing and Signal Reconstruction Based on Blind Separation Technology

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China Communications 2024年第2期21卷 85-95页

作者： Chengjie Li lidong zhu Zhen Zhang The Key Laboratory for Computer Systems of State Ethnic Affairs Commission School of Computer Science and Technology(Southwest Minzu University)Chengdu 610000China National Key Laboratory of Science and Technology on Communications(University of Electronic Science and Technology of China) Chengdu 610000China College of Computer Science(Sichuan University) Chengdu 610000China

In LEO satellite communication networks,the number of satellites has increased sharply, the relative velocity of satellites is very fast, then electronic signal aliasing occurs from time to time. Those aliasing signals make the receiving ability of the signal receiver worse, the signal processing ability weaker,and the anti-interference ability of the communication system lower. Aiming at the above problems, to save communication resources and improve communication efficiency, and considering the irregularity of interference signals, the underdetermined blind separation technology can effectively deal with the problem of interference sensing and signal reconstruction in this scenario. In order to improve the stability of source signal separation and the security of information transmission, a greedy optimization algorithm can be executed. At the same time, to improve network information transmission efficiency and prevent algorithms from getting trapped in local optima, delete low-energy points during each iteration process. Ultimately, simulation experiments validate that the algorithm presented in this paper enhances both the transmission efficiency of the network transmission system and the security of the communication system, achieving the process of interference sensing and signal reconstruction in the LEO satellite communication system.

关键词： blind source separation greedy optimization algorithm interference sensing LEO satellite communication networks signal reconstruction

Independent Component Analysis Based Blind Adaptive Interference Reduction and Symbol Recovery for OFDM Systems

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China Communications 2016年第2期13卷 41-54页

作者： LUO Zhongqiang zhu lidong LI Chengjie National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of China

To overcome the inter-carrier interference （ICI） of orthogonal frequency division multiplexing （OFDM） systems subject to unknown carrier frequency offset （CFO） and multipath, this paper develops a blind adaptive interference suppression scheme based on independent component analysis （ICA）. Taking into account statistical independence of subcarriers＇ signals of OFDM, the signal recovery mechanism is investigated to achieve the goal of blind equalization. The received OFDM signals can be considered as the mixed observation signals. The effect of CFO and multipath corresponds to the mixing matrix in the problem of blind source separation （BSS） framework. In this paper, the ICA- based OFDM system model is built, and the proposed ICA-based detector is exploited to extract source signals from the observation of a received mixture based on the assumption of statistical independence between the sources. The blind separation technique can increase spectral efficiency and provide robustness performance against erroneous parameter estimation problem. Theoretical analysis and simulation results show that compared with the conventional pilot-based scheme, the improved performance of OFDM systems is obtained by the proposed ICA-based detection technique.

关键词： orthogonal frequency divisionmultiplexing (OFDM) blind source separation(BSS) independent component analysis (ICA) blind interference suppression symbol recovery

Robust Blind Separation for MIMO Systems against Channel Mismatch Using Second-Order Cone Programming

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China Communications 2017年第6期14卷 168-178页

作者： Zhongqiang Luo Chengjie Li lidong zhu School of Automation & Information Engineering Sichuan University of Science and Engineering National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of China

To improve the deteriorated capacity gain and source recovery performance due to channel mismatch problem,this paper reports a research about blind separation method against channel mismatch in multiple-input multiple-output(MIMO) *** channel mismatch problem can be described as a channel with bounded fluctuant errors due to channel distortion or channel estimation *** problem of blind signal separation/extraction with channel mismatch is formulated as a cost function of blind source separation(BSS) subject to the second-order cone constraint,which can be called as second-order cone programing optimization *** the resulting cost function is solved by approximate negentropy maximization using quasi-Newton iterative methods for blind separation/extraction source *** analysis demonstrates that the proposed algorithm has low computational complexity and improved performance *** results verify that the capacity gain and bit error rate(BER) performance of the proposed blind separation method is superior to those of the existing methods in MIMO systems with channel mismatch problem.

关键词： multiple-input multiple-output channel mismatch second-order cone programming blind source separation independent component analysis

Underdetermined Blind Source Separation of Adjacent Satellite Interference Based on Sparseness

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China Communications 2017年第4期14卷 140-149页

作者： Chengjie Li lidong zhu Zhongqiang Luo National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of China School of Automation & Information Engineering Sichuan University of Science and Engineering

The problem of underdetermined blind source separation of adjacent satellite interference is proposed in this paper. Density Clustering algorithm(DC-algorithm) presented in this article is different from traditional methods. Sparseness representation has been applied in underdetermined blind signal source separation. However, some difficulties have not been considered, such as the number of sources is unknown or the mixed matrix is ill-conditioned. In order to find out the number of the mixed signals, Short Time Fourier Transform(STFT) is employed to segment received mixtures. Then, we formulate the blind source signal as cluster problem. Furthermore, we construct Cost Function Pair and Decision Coordinate System by using density clustering. At the end of this paper, we discuss the performance of the proposed method and verify the novel method based on several simulations. We verify the proposed method on numerical experiments with real signal transmission, which demonstrates the validity of the proposed method.

关键词： adjacent satellite interference Short Time Fourier Transform Decision Coordinate System real signal transmission

Energy-Efficient Traffic Offloading for RSMA-Based Hybrid Satellite Terrestrial Networks with Deep Reinforcement Learning

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China Communications 2024年第2期21卷 49-58页

作者： Qingmiao Zhang lidong zhu Yanyan Chen Shan Jiang National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of ChinaChengdu 611731China The Higher Educational Key Laboratory for Flexible Manufacturing Equipment Integration of Fujian Province Xiamen Institute of TechnologyXiamen 361021China China Mobile(Jiangxi)Communications Group Co. LtdYichun 336000China

As the demands of massive connections and vast coverage rapidly grow in the next wireless communication networks, rate splitting multiple access(RSMA) is considered to be the new promising access scheme since it can provide higher efficiency with limited spectrum resources. In this paper, combining spectrum splitting with rate splitting, we propose to allocate resources with traffic offloading in hybrid satellite terrestrial networks. A novel deep reinforcement learning method is adopted to solve this challenging non-convex problem. However, the neverending learning process could prohibit its practical implementation. Therefore, we introduce the switch mechanism to avoid unnecessary learning. Additionally, the QoS constraint in the scheme can rule out unsuccessful transmission. The simulation results validates the energy efficiency performance and the convergence speed of the proposed algorithm.

关键词： deep reinforcement learning energy efficiency hybrid satellite terrestrial networks rate splitting multiple access traffic offloading

Deep Unfolding for Cooperative Rate Splitting Multiple Access in Hybrid Satellite Terrestrial Networks

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China Communications 2022年第7期19卷 100-109页

作者： Qingmiao Zhang lidong zhu Shan Jiang Xiaogang Tang National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of ChinaChengdu 611731China China Mobile(Jiangxi)Communications Group Co. LtdYichun 336000China School of Aerospace Information Space Engineering UniversityBeijing 101416China

Rate splitting multiple access(RSMA)has shown great potentials for the next generation communication *** this work,we consider a two-user system in hybrid satellite terrestrial network(HSTN)where one of them is heavily shadowed and the other uses cooperative RSMA to improve the transmission *** non-convex weighted sum rate(WSR)problem formulated based on this model is usually optimized by computational burdened weighted minimum mean square error(WMMSE)*** propose to apply deep unfolding to solve the optimization problem,which maps WMMSE iterations into a layer-wise network and could achieve better performance within limited *** also incorporate momentum accelerated projection gradient descent(PGD)algorithm to circumvent the complicated operations in WMMSE that are not amenable for unfolding and *** momentum and step size in deep unfolding network are selected as trainable parameters for *** shown in the simulation results,deep unfolding scheme has WSR and convergence speed advantages over original WMMSE algorithm.

关键词： hybrid satellite terrestrial network rate splitting multiple access cooperative transmission deep unfolding weighted minimum mean square error

Change and significance of T-cell subsets and TNF-α in patients with advanced malignant obstructive jaundice treated by percutaneous transhepatic biliary external and internal drainage

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Frontiers of Medicine 2007年第4期1卷 364-368页

作者： zhu lidong CHEN Xiaoping Department of Surgery Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Department of Surgery Linyi Tumor HospitalLinyi 276001China

The aim of this article was to study the influence of immunity function of advanced malignant obstructive jaundice(MOJ)treated by percutaneous transhepatic biliary external and internal ***-six cases of MOJ were divided into two groups according to the different ways of biliary ***-two external drainage tubes were placed in 41 cases of percutaneous transhepatic biliary exter-nal drainage group and 66 metal stents were placed in 55 cases of percutaneous transhepatic biliary internal drainage *** function,serum TNF-α and cellular function were examined one day before operation and one week after operation and liver function was re-examined two weeks after operation,in order to observe the change and analyze the association among them and compare with the control *** patients’conditions were improved after *** the percutaneous transhepatic biliary external and internal drainage groups,the total level of bilirubin decreased from(343.54±105.56)μmol/L and(321.19±110.50)μmol/L to(290.56±103.46)μmol/L and(283.72±104.95)μmol/L after operation respectively,which were significantly lower than pre-operation(P0.05).Serum alanine aminotransferase(ALT)of all patients one week after opera-tion was significantly lower than that before ***-a in percutaneous transhepatic biliary external and internal groups decreased from(108.58±19.95)pg/mL,(109.98±16.24)pg/mL of pre-operation to(104.32±19.59)pg/mL,(83.92±13.43)pg/mL of post-operation respectively,there was notable improvement(P0.05).There was a significant difference between the two *** TNF-α and ALT had positive *** transhepatic biliary internal or external drain-age was an effective

关键词： jaundice,obstructive percutaneous transhepatic biliary external and internal drainage TNF-α

Effective Methods and Performance Analysis on Data Transmission Security with Blind Source Separation in Space-Based AIS

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China Communications 2022年第4期19卷 154-165页

作者： Chengjie Li lidong zhu Zhongqiang Luo Zhen Zhang Ying Yang The Key Laboratory for Computer Systems of State Ethnic Affairs Commission School of Computer Science and Technology(Southwest Minzu University)Chengdu 610000China National Key Laboratory of Science and Technology on Communications(University of Electronic Science and Technology of China) Chengdu 610000China Sichuan University of Science&Engineering ZigongChina College of Computer Science(Sichuan University) Chengdu 610000China

In space-based Automatic Identification Systems(AIS), due to high satellite orbits, several Ad Hoc cells within the observation range of the satellite are vulnerable to interference by an external *** increase efficiency in target detection and improve system security, a blind source separation method is adopted for processing the conflicting signals received by satellites. Compared to traditional methods, we formulate the separation problem as a clustering problem. Since our algorithm is affected by the sparseness of source signals, to get satisfactory results, our algorithm assumes that the distance between two arbitrary mixed-signal vectors is less than the doubled sum of variances of distribution of the corresponding mixtures. Signal sparsity is overcome by computing the Short-Time Fourier Transform, and the mixed source signals are separated using the improved PSO clustering. We evaluated the performance and the robustness of the proposed network architecture by several simulations. The experimental results demonstrate the effectiveness of the proposed method in not only improving satellite signal receiving ability but also in enhancing space-based AIS security.

关键词： space-based automatic identification systems tolerance rough set particle swarm optimization invulnerability performance