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Coded Modulation Faster-than-Nyquist Transmission with Precoder and Channel Shortening Optimization

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China Communications 2021年第2期18卷 49-64页

Faster-than-Nyquist(FTN)signaling can improve the spectrum efficiency(SE)of the transmission *** this paper,we propose a coded modulation FTN(CM-FTN)transmission scheme with precoder and channel shortening(CS)optimization to improve bit error rate(BER)performance and reduce the complexity of FTN *** our proposal,the information rate(IR)or spectral efficiency(SE)is employed and verified as a better performance metric for CM-FTN than the minimum Euclidian distance(MED).The precoder of CM-FTN is optimized for maximizing the IR criterion using the bare-bones particle swarm optimization(BB-PSO)***,a three-carrier CM-FTN system model is used to capture the broadening effect of *** targeting for the IR maximization,the inter-symbol interference(ISI)length for CS is optimized to reduce the receiver complexity without performance *** results demonstrate that our method has a 0.6dB precoding gain compared with the nonprecoding scheme and a maximum of 87.5%of the complexity of FTN equalizer is reduced without BER loss.

关键词： faster-than-Nyquist coded modulation information rate minimum Euclidian distance precoder channel shortening

A Revised Graduated Cylindrical Shell Model and its Application to a Prominence Eruption

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Research in Astronomy and Astrophysics 2023年第12期23卷 63-72页

作者： Qing-Min Zhang Zhen-yong Hou Xian-yong bai Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryNanjing 210023China Yunnan Key Laboratory of the Solar Physics and Space Science Kunming 650216China School of Earth and Space Sciences Peking UniversityBeijing 100871China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Solar Activity and Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China

In this paper,the well-known graduated cylindrical shell(GCS)model is slightly revised by introducing longitudinal and latitudinal deflections of prominences originating from active regions(ARs).Subsequently,it is applied to the three-dimensional(3D)reconstruction of an eruptive prominence in AR 13110,which produced an M1.7 class flare and a fast coronal mass ejection(CME)on 2022 September *** is revealed that the prominence undergoes acceleration from~246 to~708 km s^(-1).Meanwhile,the prominence experiences southward deflection by 15°±1°without longitudinal deflection,suggesting that the prominence erupts *** deflections of the prominence and associated CME are consistent,validating the results of fitting using the revised GCS ***,the true speed of the CME is calculated to be 1637±15 km s^(-1),which is~2.3 times higher than that of *** is indicative of continuing acceleration of the prominence during which flare magnetic reconnection reaches maximum beneath the erupting ***,the reconstruction using the revised GCS model could successfully track a prominence in its early phase of evolution,including acceleration and deflection.

关键词： Sun flares-Sun filaments-prominences-Sun coronal mass ejections(CMEs)

MODIFIED BERNOULLI ITERATION METHODS FOR QUADRATIC MATRIX EQUATION

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Journal of Computational Mathematics 2007年第5期25卷 498-511页

作者： Zhong-Zhi bai yong-Hua Gao LSEC ICMSEC Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China

We construct a modified Bernoulli iteration method for solving the quadratic matrix equation AX^2 ＋ BX ＋ C = 0, where A, B and C are square matrices. This method is motivated from the Gauss-Seidel iteration for solving linear systems and the ShermanMorrison-Woodbury formula for updating matrices. Under suitable conditions, we prove the local linear convergence of the new method. An algorithm is presented to find the solution of the quadratic matrix equation and some numerical results are given to show the feasibility and the effectiveness of the algorithm. In addition, we also describe and analyze the block version of the modified Bernoulli iteration method.

关键词： Quadratic matrix equation Quadratic eigenvalue problem Solvent Bernoulli's iteration Newton's method Local convergence.

Jitter Enhanced Full Digital RF Transmitter and PWM RFPA for 5G Broadband Communications

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China Communications 2022年第5期19卷 69-86页

作者： Linxin Yin Dake Liu yong bai The State Key Laboratory of Marine Resources Utilization in South China Sea Hainan UniversityHaikou 570228China School of Information and Communication Engineering Hainan UniversityHaikou 570228China

RFPA(radio frequency power amplifier)based on PWM(pulse width modulation)can be perfect linear without using complicated DPD(digital pre-distortion)***,PWM RFPA need ultra-high PWM time resolution(less than 10 ps)for wide-band 5G,which is limited by CMOS technologies(can reach 40 ps).It limits the complexity of modulation so that PWM RFPA cannot be really commercialized so far in wideband radio/mobile *** paper presents our contribution by introducing jitter into *** the first time,we demonstrate that jitter can improve the PWM time resolution equivalently reaching less than 2.6 *** PWM RFPA can be used in 5G supporting 256QAM OFDM modulation based on currently available digital CMOS *** demonstrate that jitter can refine the inherent resolution of PWM hardware circuit *** jitter makes the MCS(modulation and coding scheme)of the bandwidth OFDM system improved from 16QAM to 256QAM in the band n28 of 3GPP *** also verified that 5G 256QAM OFDM modulation is achievable in the 3GPP band n20,Softbank band28 and NTT Docomo *** RMS EVM(root mean square error vector magnitude)of 256QAM OFDM modulation is about-44 dB.

关键词： PWM RFPA OFDM jitter 256QAM EVM

General Galois Processor for Transmitters in 5G/6G Base Stations

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China Communications 2021年第10期18卷 129-134页

作者： Qingbo Zhai yong bai Dake Liu State Key Laboratory of Marine Resource Utilization in South China Sea College of Information and Communication EngineeringHainan UniversityHaikou 570228Hainan ProvinceChina

This paper proposes a flexible eight-mode high parallel Galois SIMD ASIP(Application Specific Instruction Set Processor).It supports parallel executions of Gold,Scrambling,CRC,CC,Turbo,RM,PSS,SSS encoding LFSR(linear feedback shift registers)algorithms with high performance and *** can perform also general bit processing and *** design is based on proposed table conversion and a datapath for unified eight-mode *** on 28 nm digital CMOS technology,the total area is 0.177 mm2 and the clock frequency can be up to 1 *** throughputs of Gold,Scrambling,CRC32,CRC24,CRC16,CRC8,CC,Turbo are 64 Gb/s,64 Gb/s,128 Gb/s,168 Gb/s,256 Gb/s,512 Gb/s,3×80 Gb/s,and 72 Gb/s,respectively.

关键词： multi-mode parallel encoding ASIP SIMD URLLC 5G base station

Analysis of Vanadium-Bearing Titanomagnetite Sintering Process by Dissection of Sintering Bed

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Journal of Iron and Steel Research International 2011年第6期18卷 8-15,36页

作者： bai yong-qiang CHENG Shu-sen bai Yan-ming School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing100083 Chinas Chenggang Company Hebei Iron and Steel Co Ltd Chengde 062001 Hebei China

Many problems appear in the sintering process of vanadium-bearing titanomagnetite, such as high energy consumption and low productivity; simer quality is also very poor for its low tumble strength and high reduction deg- radation. Sinter productivity and quality are dominated by bed permeability and mineralogy structure, which are highly influenced by the thermal state of sintering bed, so the sintering process of titanomagnetite is researched by bed dissection in this work. Temperature evolution curves of sinter materials were measured, and the results show that melting duration, peak temperature duration and sintering temperature of different layers differ greatly from each other; flame front speed and vertical sintering speed of bed lower region are much smaller than those of bed up- per region. Simultaneously, sinter samples were collected from different layers, and their mineralogy characteristics are analyzed; sinters from bed lower region have poor mineralogy structure, and the amounts of perovskite and dieM- cium silicate increase intensively, which are bad for sinter strength and reduction degradation property. Measures are proposed to improve the quality and productivity of titanomagnetite sinter.

关键词： sintering vanadium hearing titanomagnetite thermal state bed dissection mineralogy characteristic

Faster-than-Nyquist signaling based on filter bank multicarrier modulation with joint optimization

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Journal of Systems Engineering and Electronics 2022年第6期33卷 1208-1223页

作者： CHE Hui PENG Dingxiang GUO Fachang bai yong School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Ruijie Networks Co. LtdFuzhou 350002China School of Information and Communication Engineering Hainan UniversityHaikou 570228China

Multi-carrier faster-than-Nyquist(MFTN)can improve the spectrum efficiency(SE).In this paper,we first analyze the benefit of time frequency packing MFTN(TFP-MFTN).Then,we propose an efficient digital implementation for TFP-MFTN based on filter bank multicarrier *** time frequency packing ratio pair in our proposed implementation scheme is optimized with the SE ***,the joint optimization for the coded modulation MFTN based on extrinsic information transfer(EXIT)chart is *** Monte-Carlo simulations are carried out to verify performance gain of the joint inner and outer code *** results demonstrate that the TFPMFTN has a 0.8 dB and 0.9 dB gain comparing to time packing MFTN(TP-MFTN)and higher order Nyquist at same SE,respectively;the TFP-MFTN with optimized low density parity check(LDPC)code has a 2.9 dB gain comparing to that with digital video broadcasting(DVB)*** with previous work on TFP-MFTN(SE=1.55 bit/s/Hz),the SE of our work is improved by 29%and our work has a 4.1 dB gain at BER=1×10^(-5).

关键词： faster-than-Nyquist filter bank multi-carrier time-frequency packing(TFP) spectrum efficiency(SE) joint optimization

A Novel Photoproduct of 1, 3-Dimethyluracil in Phosphate Buffered-saline

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Chinese Chemical Letters 2005年第9期16卷 1158-1160页

作者： Feng LIN Shao yong bai Department of Chemistry Xi-xi Campus Zhejiang University Hangzhou 310028

1, 3-Dimethyluracil （DMU） in phosphate buffered-saline （PBS, pH=8） was irradiated by a medium pressure mercury lamp （MPML） and produced a novel compound C6H9N2O6P. The composition and structure of the compound h... 详细信息

关键词： UV Photolysis 1 3-dimethyluracil phosphate buffered-saline(PBS)

Slope structures and formation of rock–soil aggregate landslides in deeply incised valleys

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Journal of Mountain Science 2020年第2期17卷 316-328页

作者： bai yong-jian WANG Yun-sheng GE Hua TIE yong-bo State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of technologyChengdu 610059China Chengdu Center of China Geological Survey Chengdu 610081China

Rock–soil aggregate landslides(RSALs) are a common geological hazard in deeply incised valleys in southwestern China. Large-scale RSALs are widely distributed in the upper reaches of the Dadu River, Danba County, Sichuan Province, and are influenced by slope structure, which can be divided into open, lock, strip, and dumbbell types, as well as soil type and meso-structure, which can be classified as layered rock–soil aggregate, block-soil, and grainsoil. In this study, the evolution of four types of structures, such as layered-dumbbell, block-soil lock, banded block-soil, and block-soil open types, were analyzed by field surveys, surface and deep displacement monitoring, and Flac3 D. It was found that the Danba reach of the Dadu River showed incised valley through the evolution from wide to slow valley affected by internal and external geological processes since the Quaternary Glaciation. In the layered-dumbbell rock–soil aggregate, the main sliding pattern is multi-stage sliding at different depths. Circular sliding in the trailing edge and plane sliding along the bedrock in the front edge body occurin the block-soil-lock type aggregate. Large-scale multi-level and circular sliding over long distances occur in the banded block-soil aggregate. The blocksoil open type is stable, with only circular sliding occurring in local and shallow surfaces of the body. The monitoring and numerical simulation results further show that slope structure and regularity have diversified with RSALs. The results provide a basis for analyzing the stability mechanism of RSALs and preventing RSALs in deeply incised valleys.

关键词： Slope structures Formation evolution Rock–soil aggregate Deeply incised valleys