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New Applications of EXIT Chart for Iterative Decoding Systems
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作者 宫丰奎 葛建华 李兵兵 《Journal of Shanghai Jiaotong university(Science)》 EI 2008年第1期35-39,共5页
Applications on iterative control and multiple input multiple output (MIMO) system were developed. Two new charts derived from extrinsic information transfer (EXIT) chart were employed as the designing tools, which ar... Applications on iterative control and multiple input multiple output (MIMO) system were developed. Two new charts derived from extrinsic information transfer (EXIT) chart were employed as the designing tools, which are called as output mutual information chart with defined iterative degree (DID) chart and near optimum output mutual information (NOMI) chart respectively. Different from the EXIT chart, they can show the iterative performance on the whole signal-to-noise ratio range with one single curve, whereas computation complexity is greatly reduced compared with conventional bit error ratio (BER) performance curve. The iterative control was implemented according to a near-optimum iterative degree vector determined by NOMI chart, the reasonability of uncertain parameters was analyzed in one MIMO system. The concepts were illustrated based on bit-interleaved coded modulation with iterative decoding (BICM-ID). 展开更多
关键词 extrinsic information transfer chart bit-interleaved coded modulation iterative decoding multiple input multiple output
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关于信息化海洋测绘问题的探讨 被引量:7
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作者 翟国君 黄谟涛 《海洋测绘》 2014年第5期1-6,共6页
针对信息化海洋测绘这一重要问题进行了探讨,就目前存在的一些模糊认识进行了分析澄清。对相关文献涉及的数据信息准确性、语言表述严谨性和学术观点合理性问题,进行了核实和讨论,提出了我们的观点:一是认为对一些重要数据的引用有误,... 针对信息化海洋测绘这一重要问题进行了探讨,就目前存在的一些模糊认识进行了分析澄清。对相关文献涉及的数据信息准确性、语言表述严谨性和学术观点合理性问题,进行了核实和讨论,提出了我们的观点:一是认为对一些重要数据的引用有误,容易误导读者,影响到引用数据的权威性;二是认为海洋测绘一直就归属于测绘学科,而不是游离其外,更不宜将其纳入海洋学;三是认为不能简单用海图集合这个概念来代替海洋测绘的成果或数据集合,海图集合论不是海洋测绘的核心理论;四是认为海洋测绘一直就是按照纵向分离、横向融合的理念和模式发展的,不依信息化进程而改变,改变的只是它的发展深度和广度。 展开更多
关键词 测绘学 海洋测绘 信息化 海图集合 探讨
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信息化或被信息化的海洋测绘 被引量:10
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作者 翟京生 《测绘科学技术学报》 CSCD 北大核心 2013年第4期388-391,共4页
不管是10年、20年,或是更长的时间,也不管是否愿意,海洋测绘都将被信息化,也只有信息化,才是影响和推动海洋测绘变革的根本动力。可是,信息化不是一个单纯的技术问题,会导致观念、理论、方法、体制等的变革。本文结合多年的技术实践,探... 不管是10年、20年,或是更长的时间,也不管是否愿意,海洋测绘都将被信息化,也只有信息化,才是影响和推动海洋测绘变革的根本动力。可是,信息化不是一个单纯的技术问题,会导致观念、理论、方法、体制等的变革。本文结合多年的技术实践,探讨了信息化海洋测绘的本源,提出了海图集合论的概念,给出了一个横向融合、纵向分离的技术体系,目的是推动海洋测绘信息化技术的变革。 展开更多
关键词 信息化 海洋测绘 海图集合 横向融合 纵向分离
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现代技术发展对海图质量的影响与对策 被引量:1
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作者 贾建军 李钏 李庆伟 《海洋测绘》 2011年第3期77-79,共3页
分析了以数字制图技术、多波束水深测量技术、卫星导航定位技术为代表的现代技术在海图设计、生产和使用过程的应用特点,以这些技术本身的发展给海图的生产技术、产品形式和使用方式所带来的影响为切入点,重点分析了由于这些技术的发展... 分析了以数字制图技术、多波束水深测量技术、卫星导航定位技术为代表的现代技术在海图设计、生产和使用过程的应用特点,以这些技术本身的发展给海图的生产技术、产品形式和使用方式所带来的影响为切入点,重点分析了由于这些技术的发展应用对海图的质量产生了哪些新的重要影响,并就如何消除不利影响、提高海图质量进行了讨论。 展开更多
关键词 现代技术 海图质量 数字化 信息化
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Optimized LDPC differential-encoded 16QAM scheme for high-speed transmission systems 被引量:1
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作者 Zhanji Wu Xiang Gao Zhiyu Xiao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第5期728-734,共7页
The 16-ary quadrature amplitude modulation (16QAM) is a high spectral efficient scheme for high-speed transmission systems. To remove the phase ambiguity in the coherent detection system, differential-encoded 16QAM ... The 16-ary quadrature amplitude modulation (16QAM) is a high spectral efficient scheme for high-speed transmission systems. To remove the phase ambiguity in the coherent detection system, differential-encoded 16QAM (DE-16QAM) is usually used, however, it will cause performance degradation about 3 dB as compared to the conventional 16QAM. To overcome the performance loss, a serial concatenated system with outer low density parity check (LDPC) codes and inner DE-16QAM is proposed. At the receiver, joint iterative differential demodulation and decoding (ID) is carried out to approach the maximum likelihood performance. Moreover, a genetic evolution algorithm based on the extrinsic information transfer chart is proposed to optimize the degree distribution of the outer LDPC codes. Both theoretical analyses and simulation results indicate that this algorithm not only compensates the performance loss, but also obtains a significant performance gain, which is up to 1 dB as compared to the conventional non-DE-16QAM. 展开更多
关键词 quadrature amplitude modulation (QAM) low density parity check (LDPC) code genetic evolution (GE) algorithm iterative demodulation and decoding (ID) extrinsic information transfer (EXIT) chart.
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Network Coding Based on Linear Block Codes for Multi-source Cooperative Relaying Networks
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作者 李宗艳 李世银 李德亮 《Journal of Donghua University(English Edition)》 EI CAS 2013年第6期504-509,共6页
In order to improve link performance of future wireless relay networks,a network coding scheme with linear block codes was proposed,which could be deployed in a relay network consisting of multi-source sending data to... In order to improve link performance of future wireless relay networks,a network coding scheme with linear block codes was proposed,which could be deployed in a relay network consisting of multi-source sending data to a common base station(BS) with the assistance of one relay node.At BS,an iterative decoding structure between one cooperative decoder and a number of single-source decoders was established using the relayed network codes and source codes.Further,the extrinsic information transfer(EXIT) chart technique was used to predict and analyze the convergence behavior of iterative decoder.The analysis and simulation results show that the bit error ratio(BER) performance of the proposed scheme outperforms reference scheme under different relay network coding matrices.Compared with a reference scheme without the multisource cooperation,the proposed scheme can obtain network coding gain from the relay network while not reduce its code rate. 展开更多
关键词 multiple access relay channel iterative decoding extrinsic information transfer chart converfence
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Improved iterative convergence method in Q-ary LDPC coded high order PR-CPM
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作者 Danfeng Zhao Yanbo Sun Rui Xue 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第3期541-548,共8页
The Q-ary low-density parity-check(LDPC) coded high order partial response continuous phase modulation(PR-CPM) with double iterative loops is investigated. This scheme shows significant improvements in power and b... The Q-ary low-density parity-check(LDPC) coded high order partial response continuous phase modulation(PR-CPM) with double iterative loops is investigated. This scheme shows significant improvements in power and bandwidth efficiency, but at the expense of long iterative decoding delay and computational complexity induced by the improper match between the demodulator and the decoder. To address this issue, the convergence behavior of Q-ary LDPC coded CPM is investigated for the Q=2 and Q〉2 cases, and an optimized design method based on the extrinsic information transfer chart is proposed to improve the systematic iterative efficiency. Simulation results demonstrate that the proposed method can achieve a perfect tradeoff between iterative decoding delay and bit error rate performance to satisfy real-time applications. 展开更多
关键词 iterative detection convergence low-density paritycheck(LDPC) code continuous phase modulation(CPM) extrinsic information transfer chart
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A NOVEL ITERATIVE SCHEME FOR PARALLEL INTER-SYMBOL INTERFERENCE CHANNELS
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作者 Cheng Xiang Yuan Dongfeng 《Journal of Electronics(China)》 2007年第1期50-53,共4页
In this paper,we propose a novel iterative scheme for exploiting transmit diversity using parallel independent Inter-Symbol Interference (ISI) channels. In this adaptive iterative scheme,we use EXtrinsic Information T... In this paper,we propose a novel iterative scheme for exploiting transmit diversity using parallel independent Inter-Symbol Interference (ISI) channels. In this adaptive iterative scheme,we use EXtrinsic Information Transfer (EXIT) chart tool to choose appropriate iterative method from Itera-tive Combining (IC),used as parallel concatenation turbo-like scheme,and Turbo Equalization (TE),used as serial concatenation turbo-like scheme. It is show that the proposed iterative scheme provides excellent performance both analytically and through simulations without any compute complexity increase comparable to IC. 展开更多
关键词 iterative method Turbo Equalization (TE) Iterative Combining (IC) EXtrinsic information Transfer (EXIT) chart Inter-Symbol Interference (ISI)
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DESIGN OF LOW-DENSITY PARITY CHECK CODES FOR MIMO SYSTEMS WITH DOUBLY-ITERATIVE RECEIVERS
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作者 Mei Zhonghui Li Xiaofei 《Journal of Electronics(China)》 2010年第4期553-556,共4页
In this paper, the Multiple Input Multiple Output (MIMO) doubly-iterative receiver which consists of the Probabilistic Data Association detector (PDA) and Low-Density Parity-Check Code (LDPC) decoder is developed. The... In this paper, the Multiple Input Multiple Output (MIMO) doubly-iterative receiver which consists of the Probabilistic Data Association detector (PDA) and Low-Density Parity-Check Code (LDPC) decoder is developed. The receiver performs two iterative decoding loops. In the outer loop, the soft information is exchanged between the PDA detector and the LDPC decoder. In the inner loop, it is exchanged between variable node and check node decoders inside the LDPC decoder. On the light of the Extrinsic Information Transfer (EXIT) chart technique, an LDPC code degree profile optimization algorithm is developed for the doubly-iterative receiver. Simulation results show the doubly-receiver with optimized irregular LDPC code can have a better performance than the one with the regular one. 展开更多
关键词 Probabilistic Data Association (PDA) Multiple-Input Multiple-Output (MIMO) Low-Density Parity-Check Code (LDPC) Extrinsic information Transfer (EXIT) chart
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