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An iterative BiGAMP-based receiver for coded massive MIMO systems with low-resolution ADCs

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Science China(Information Sciences) 2021年第11期64卷 247-248页

作者： Yi SUN Ming JIANG chunming zhao National Mobile Communications Research Laboratory Southeast University Purple Mountain Laboratories

Dear editor,The hundreds of antennas deployed in massive multipleinput-multiple-output(MIMO) systems lead to an insupportable burden in terms of hardware costs and power consumption. This has motivated the research on... 详细信息

关键词： Information Systems and Communication Service

Partial CRC-aided decoding of 5G-NR short codes using reliability information

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Science China(Information Sciences) 2019年第8期62卷 35-43页

作者： Ming JIANG Zhengyi LI Xiao YANG chunming zhao National Mobile Communications Research Laboratory Southeast University

In this paper, we focus on how to further enhance the performance of the channel codes in order to meet the more stringent reliability requirements of future networks(5G and beyond). A general decoder with the aid of partial cyclic redundancy check(CRC) bits is proposed for the polar codes and short low-density parity-check(LDPC) codes in 5G systems. The decoder based on ordered statistic decoding(OSD) method can effectively improve the error-correction performance on the condition that extra CRC bits are used to assist in decoding. Meanwhile, the remaining part of CRC keeps its capability of errordetection to guarantee the undetected error rate low enough. This paper gives the detailed implementation schemes of the partial CRC-aided OSD process and its combination with the conventional decodings of the LDPC/polar codes in 5G systems. The simulation results show our proposed decoding scheme achieves a promising trade-off between the performance gain and the error-detection capabilities.

关键词： polar codes LDPC codes CRC codes successive cancellation list decoding ordered statistic decoding

Turbo iterative equalization for HSDPA systems

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Science in China(Series F) 2007年第1期50卷 105-112页

作者： WU QiHui zhao chunming WANG JinLong Department of Radio Engineering Southeast University Nanjing 210096 China Institute of Communications Engineering Nanjing 210007 China

in this paper, a turbo Iterstive receiver structure with chip equalization is proposed for the 3G high-speed downllnk packet access （HSDPA） systems. The receiver equalizes the channel prior to the dlspreadlng and then performs two successive soft-output decisions, achieved by s soft-Input soft-output （SISO） multi-code detector and a SISO turbo decoder through an Iteratlve process. At each Iteration, extrinsic information Is extracted from detection and decoding stages and Is then used as a priori Information In the next Iteration, Just as In turbo decoding. Computer simulations show that the turbo Iterstlve receiver structure with chip equsllzation offers significant performance gain over the traditional receiver structure.

关键词： chip equalization HSDPA multi-code detection turbo code turbo processing

A low-floor bit-mapping scheme for LDPC coded BICM for 5G and beyond systems

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Science China(Information Sciences) 2023年第10期66卷 263-277页

作者： Mingyang ZHU Ming JIANG chunming zhao Lijie HU Xiaodong XU National Mobile Communications Research Laboratory Southeast University Purple Mountain Laboratories China Mobile Research Institute

This paper proposes a low-floor bit-mapping(LFBM) scheme for bit-interleaved coded modulation(BICM) systems to meet more stringent quality of service requirements of 5G and beyond. For highefficiency transmissions, we consider the 5G low-density parity-check codes with high-order 2m-quadrature amplitude modulations(QAMs). The proposed LFBM scheme overcomes plenty of trapping sets induced by the bit interleaver, which focuses on the waterfall performance too aggressively. When the high-order QAM is used, the row-column interleaver specified by the 5G standard is such a bit interleaver. The LFBM scheme only optimizes the rule of mapping an m-bit tuple output by the row-column interleaver to a modulation symbol, rather than the entire bit interleaver. Therefore, the optimized bit mapper is actually an m-bit permutation module concatenated with the original bit interleaver employed in the current 5G BICM *** simulation results confirm that the LFBM scheme can lower the error floor of the 5G BICM system by approximately two orders of magnitude, while with negligible performance loss in the waterfall region.

关键词： bit-interleaved coded modulation low-density parity-check codes error floors bit mapping high-order modulation

Low complexity Chase-2 decoding of concatenated codes

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Chinese Science Bulletin 2010年第26期55卷 3066-3070页

作者： LIU XiaoJian zhao chunming SUN XiaoJun National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China

The concatenated codes are widely used in current communication systems, such as satellite communication systems and WiMAX system. The objective of this study was to present a low complexity iterative soft decoding algorithm for concatenated codes. The concatenation was between a Reed-Solomon (RS) code and recursive systematic convolutional (RSC) code. The reduction in computational complexity was achieved by simplifying the Chase-2 decoder for RS codes with limited usage of test patterns. The processing of soft information between inner and outer decoders was also discussed. Simulation results showed that the proposed algorithm could achieve a good trade-off between complexity and performance.

关键词：级联码大通卫星通信系统计算复杂性译码解码算法低复杂度限制使用

The Structure of China＇s Imports： A New Framework

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China & World Economy 2015年第5期23卷 85-103页

作者： Hao Wei chunming zhao Professor School of Economics and Business Administration Beijing Normal University Beijing China.

Using the elbow function method to determine the number of classification groups of goods and applying the K-means algorithm to classify technical goods, this paper constructs a scientific classification framework of commodity structure and then measures the changes in China ＂s import commodity structure. It is found, first, that from 2000 to 2012, the import commodity structure in China underwent structural change. Shares of non-agricultural primary products and high-technology products increased sigmficantly, whereas shares of low-medium-technology products and medium-high-technology products declined. Second, from 2000 to 2006, the overall technology level of China＇s imports declined, but then increased from 2007 to 2012. Therefore, the Chinese Government shouM increase the share of high-technology and extra- high-technology products in total imports to stimulate structural transformation in manufacturing industries to make full use of foreign advanced technology and to prevent stepping into a low-end import commodity structure.

关键词： elbow function method import commodity structure import technology level K-means algorithm technology sophistication index

Performance evaluation for PCC-OFDM systems impaired by carrier frequency offset over AWGN channels

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Science in China(Series F) 2008年第3期51卷 320-336页

作者： ZHOU Peng zhao chunming SHI ZhiHua GONG XiaoQun National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China

Orthogonal frequency division multiplexing （OFDM） is sensitive to carrier frequency offset （CFO）, which destroys the orthogonality and causes inter-carrier interference （ICI）. ICI self-cancellation schemes based on polynomial cancellation coding （PCC-OFDM） can evidently reduce the sensitivity to CFO. In this paper, we analyze the performance of PCC-OFDM systems impaired by CFO over additive white gaussian noise （AWGN） channels. Two criteria are used to evaluate the effect of CFO on performance degradations. Firstly, the closed-form expressions of the average carrier-to-interference power ratio （CIR） and the statistical average ICI power, both of which reflect the desired power loss, are presented. Simulation and analytical results show that the theoretical expressions depend crucially on the normalized frequency offset and are hardly relevant to the number of subcarriers. Secondly, by exploiting the properties of the Beaulieu series, the effect of CFO on symbol error rate （SER） and bit error rate （BER） performance for PCC-OFDM systems are exactly expressed as the sum of an infinite series in terms of the charac- teristic function （CHF） of ICI. We consider the systems modulated with binary phase shift keying （BPSK）, quadrature PSK （QPSK）, 8-ary PSK （8-PSK）, and 16-ary quadrature amplitude modulation （16-QAM）, and all above modulation schemes are mapped with Gray codes for the evaluations of BER.

关键词： PCC-OFDM carrier frequency offset (CFO) CIR ICI Power SER gray mapping BER beaulieu series,characteristic function (CHF)

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基于国产芯片车规应用的测试评价体系研究

时代汽车 2025年第2期 13-15页

作者：王彪赵玮杰周能辉赵春明天津易鼎丰动力科技有限公司天津300380 新加坡南洋理工大学电气与电子工程学院新加坡639798

国产芯片基础研究薄弱,车规应用经验不足,目前主要应用在车窗、照明冷却系统等相对简单的控制功能领域。为有效保证国产芯片方案域控制器的可靠性,本文章开展了基于国产芯片车规应用的芯片级别、系统级别、整车级别三层级测试流程,并提... 详细信息

国产芯片基础研究薄弱,车规应用经验不足,目前主要应用在车窗、照明冷却系统等相对简单的控制功能领域。为有效保证国产芯片方案域控制器的可靠性,本文章开展了基于国产芯片车规应用的芯片级别、系统级别、整车级别三层级测试流程,并提出“五维度”案例生成规则及方法,建立了全类别、全工况、全周期、全参数的国产车规芯片测试评价体系,为国产芯片的车规应用提供了基础化支撑体系。

关键词：国产芯片车规应用测试评价体系

Transmission capacity maximization for LED array-assisted multiuser VLC systems

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Science China(Information Sciences) 2015年第8期58卷 117-130页

作者： KONG Lei SHEN Hong XU Wei ZHANG Hua zhao chunming YOU XiaoHu National Mobile Communications Research Laboratory Southeast University

In this paper, we present a light-emitting diode(LED) array-assisted visible light communication(VLC) system. Considering the requirements of illumination, the human eye safety, and the energy saving,we optimize the optical power allocation(PA) to maximize the transmission capacity of the overall ***, we discuss two typical scenarios where the LED array in each room serves multiple users either simultaneously or in a round-robin manner. The problem corresponding to the first case turns out to be nonconvex whose globally optimal solution is hard to obtain. To address this difficult problem, we first adopt the famous gradient projection algorithm to obtain a locally optimal solution, then we employ powerful convex relaxation techniques, and achieve a high-quality solution. While for the round-robin case, we are able to derive an optimal solution in closed form by virtue of Karush-Kuhn-Tucker conditions. Interestingly, the derived closedform solution follows a water-filling pattern with both square root and two-side clipping operations, which differs from the conventional water-filling-like PA in radiofrequency channels. Numerical results depict the performance advantage provided by the proposed PA strategies under various settings.

关键词： light-emitting diodes visible light communication power allocation multiuser transmission convex relaxation