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Polar-Coded Modulation Based on the Amplitude Phase Shift Keying Constellations

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China Communications 2017年第9期14卷 166-177页

作者： Dekun Zhou Jincheng Dai Kai Niu Chao Dong Jingyuan Sun Yi Zhang Hao Guan Key Laboratory of Universal Wireless Communication Ministry of EducationBeijing University of Posts and Telecommunications nokia beijing bell Lab

In this paper, we investigate the polarization effect of the amplitude phase shift keying(APSK) constellations. We find that the polarization effect of the APSK constellations is affected by the bit mapping and the bit loading. Traditionally, the Gray mapping is usually adopted in APSK constellations. Based on the given Gray mapping, we firstly propose the bit interleaved coded modulation polar-APSK(BICM-PA) scheme, which neglects the correlations between the bit levels by using the bit interleaver. In the BICM-PA scheme, a new metric called cumulative Bhattacharyya parameter is introduced to optimize the bit loading of the APSK constellations under the Gray mapping. Second, the multilevel coded modulation polar-APSK(MLCM-PA) is proposed to further improve the performance. A twostage optimization approach is adopted to select the bit mapping and the bit loading in the MLCM-PA scheme. The semi-set partitioning mapping is introduced to achieve a better system performance in the MLCM-PA scheme. Simulation results verify the effectiveness of all the proposed metrics. In addition to this, BICM-PA and MLCM-PA both outperform the coded modulation Turbo-APSK scheme up to 1 dB.

关键词： APSK constellations BICM-PA MLCM-PA two-stage optimization semi-setpartitioning

Scaling Factor Optimization of Turbo-Polar Iterative Decoding

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China Communications 2018年第6期15卷 169-177页

作者： Zhenzhen Liu Kai Niu Jiaru Lin Jingyuan Sun Hao Guan beijing University of Posts and Telecommunications Beijing 100876China nokia Shanghai bell Co. Ltd.Beijing 100876China

In this paper, we investigate the weighted iterative decoding to improve the performance of turbo-polar code. First of all, a minimum weighted mean square error criterion is proposed to optimize the scaling factors(SFs). Secondly, for two typical iterative algorithms,such as soft cancellation(SCAN) and belief propagation(BP) decoding, genie-aided decoders are proposed as the ideal reference of the practical decoding. Guided by this optimization framework, the optimal SFs of SCAN or BP decoders are obtained. The bit error rate performance of turbo-polar code with the optimal SFs can achieve 0.3 dB or 0.7 dB performance gains over the standard SCAN or BP decoding respectively.

关键词： turbo-polar code BP decoder SCAN decoder mean square error scaling factors

Free-standing microscale photonic lantern spatial mode(De-)multiplexer fabricated using 3D nanoprinting

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Light(Science & Applications) 2024年第6期13卷 1170-1185页

作者： Yoav Dana Yehudit Garcia Aleksei Kukin Lauren Dallachiesa Sterenn Guerrier Nicolas K.Fontaine Dan M.Marom Institute of Applied Physics Hebrew University of JerusalemJerusalemIsrael nokia bell labs 600 Mountain AveNew ProvidenceNJ07974USA

Photonic lantern(PL)spatial multiplexers show great promise for a range of applications,such as future high-capacity mode division multiplexing(MDM)optical communication networks and free-space optical *** enable efficient conversion between multiple single-mode(SM)sources and a multimode(MM)waveguide of the same *** multiplexers operate by facilitating adiabatic transitions between the SM arrayed space and the single MM ***,current fabrication methods are forcing the size of these devices to multi-millimeters,making integration with micro-scale photonic systems quite *** advent of 3D micro and nano printing techniques enables the fabrication of freestanding photonic structures with a high refractive index contrast(photopolymer-air).In this work we present the design,fabrication,and characterization of a 6-mode mixing,375µm long PL that enables the conversion between six single-mode inputs and a single six-mode *** PL was designed using a genetic algorithm based inverse design approach and fabricated directly on a 7-core fiber using a commercial two-photon polymerization-based 3D printer and a *** the waveguides exhibit high index contrast,low insertion loss(−2.6 dB),polarization dependent(−0.2 dB)and mode dependent loss(−4.4 dB)were measured.

关键词： mode enable printing

Nanoporous membrane device for ultra high heat flux thermal management

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Microsystems & Nanoengineering 2018年第1期4卷 474-483页

作者： Daniel F.Hanks Zhengmao Lu Jay Sircar Todd R.Salamon Dion S.Antao Kevin R.Bagnall Banafsheh Barabadi Evelyn N.Wang Massachusetts Institute of Technology 77 Massachusetts AvenueCambridgeMA 02139USA nokia bell labs 600 Mountain AvenueNew ProvidenceNJ 07974USA

High power density electronics are severely limited by current thermal management solutions which are unable to dissipate the necessary heat flux while maintaining safe junction temperatures for reliable *** designed,fabricated,and experimentally characterized a microfluidic device for ultra-high heat flux dissipation using evaporation from a nanoporous silicon ***~100 nm diameter pores,the membrane can generate high capillary pressure even with low surface tension fluids such as pentane and *** suspended ultra-thin membrane structure facilitates efficient liquid transport with minimal viscous pressure *** fabricated the membrane in silicon using interference lithography and reactive ion etching and then bonded it to a high permeability silicon microchannel array to create a biporous wick which achieves high capillary pressure with enhanced *** back side consisted of a thin film platinum heater and resistive temperature sensors to emulate the heat dissipation in transistors and measure the temperature,*** experimentally characterized the devices in pure vaporambient conditions in an environmental ***,we demonstrated heat fluxes of 665±74 W/cm^(2) using pentane over an area of 0.172mm×10mm with a temperature rise of 28.5±1.8 K from the heated substrate to ambient *** heat flux,which is normalized by the evaporation area,is the highest reported to date in the pure evaporation regime,that is,without nucleate *** experimental results are in good agreement with a high fidelity model which captures heat conduction in the suspended membrane structure as well as non-equilibrium and sub-continuum effects at the liquid–vapor *** work suggests that evaporative membrane-based approaches can be promising towards realizing an efficient,high flux thermal management strategy over large areas for high-performance electronics.

关键词： high thermal ambient

Channel Estimation and Throughput Evaluation for 5G Wireless Communication Systems in Various Scenarios on High Speed Railways

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China Communications 2018年第4期15卷 86-97页

作者： yanrong zhao xiyu wang gongpu wang ruisi he yulong zou zhuyan zhao school of computer and information technology beijing jiaotong universityBeijing 100044China the state key laboratory of rail traffic control and safety beijing jiaotong universityBeijing 100044China the key laboratory of broadband wireless communication and sensor network technology of ministry of education nanjing university of posts and telecommunicationsNanjing 210003China nokia bell labs beijing Beijing 100044China

The fifth generation （5G） wireless communication is currently a hot research topic and wireless communication systems on high speed railways （HSR） are important applications of 5G technologies. Existing stud- ies about 5G wireless systems on high speed railways （HSR） often utilize ideal channel parameters and are usually based on simple scenarios. In this paper, we evaluate the down- link throughput of 5G HSR communication systems on three typical scenarios including urban, cutting and viaduct with three different channel estimators. The channel parameters of each scenario are generated with tapped delay line （TDL） models through ray-tracing sim- ulations, which can be considered as a good match to practical situations. The channel estimators including least square （LS）, linear minimum mean square error （LMMSE）, and our proposed historical information based ba- sis expansion model （HiBEM）. We analyze the performance of the HiBEM estimator in terms of mean square error （MSE） and evaluate the system throughputs with different channel estimates over each scenario. Simulation results are then provided to corroborate our proposed studies. It is shown that our HiBEM estimator outperforms other estimators and that the sys-tem throughput can reach the highest point in the viaduct scenario.

关键词： 5G channel estimation HSR tapped delay line throughput pertbrmanceanalysis wireless communication.

Differential space-time block-diagonal codes

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Science in China(Series F) 2007年第5期50卷 747-759页

作者： LUO ZhenDong LIU YuanAn GAO dinChun School of Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China bell labs Research China AlcateI-Lucent Beijing 100080 China Department of Electronic Engineering Tsinghua University Beijing 100084 China

A new differential space-time code, called differential space-time block-diagonal code （DSTBDC）, is proposed for multiple-input multiple-output （MIMO） wireless communication systems. By exploiting the block-diagonal construction of DSTBDC, we can design a variety of high-performance DSTBDC, especially for the cases of large numbers of transmit antennas and high date rates. In flat fading channels, DSTBDC outperforms traditional differential space-time codes if the data rate is higher than 1 bps/Hz, especially when the number of transmit antennas is large. In frequency-selective fading channels, multiple-input multiple-output orthogonal frequency-division multiplexing （MIMO-OFDM） systems using DSTBDC have the powerful ability to achieve very high diversity gain in space, time, and frequency simultaneously. Due to the special orthogonal construction, DSTBDC has a simple decoding algorithm. In addition, DSTBDC can significantly save the cost of radio frequency circuits.

关键词： wireless communications MIMO systems differential modulation space-time coding OFDM

Optical fiber telecommunications V 5

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A great disturbance in the crypto:Understanding cryptocurrency returns under attacks

2008年

作者： Kaminow Ivan P. Li Tingye. Willner Alan E.

ISBN: (纸本)9780080569611

Optical Fiber Telecommunications V (A&B) is the fifth in a series that has chronicled the progress in the research and development of lightwave communications since the early 1970s. Written by active authorities from academia and industry, this edition not only brings a fresh look to many essential topics but also focuses on network management and services. Using high bandwidth in a cost-effective manner for the development of customer applications is a central theme. This book is ideal for R&D engineers and managers, optical systems implementers, university researchers and students, network operators, and the investment *** (A) is devoted to components and subsystems, including: semiconductor lasers, modulators, photodetectors, integrated photonic circuits, photonic crystals, specialty fibers, polarization-mode dispersion, electronic signal processing, MEMS, nonlinear optical signal processing, and quantum information technologies. Volume (B) is devoted to systems and networks, including: advanced modulation formats, coherent systems, time-multiplexed systems, performance monitoring, reconfigurable add-drop multiplexers, Ethernet technologies, broadband access and services, metro networks, long-haul transmission, optical switching, microwave photonics, computer interconnections, and simulation *** SketchesIvan Kaminow retired from bell labs in 1996 after a 42-year career. He conducted seminal studies on electrooptic modulators and materials, Raman scattering in ferroelectrics, integrated optics, semiconductor lasers (DBR , ridge-waveguide InGaAsP and multi-frequency), birefringent optical fibers, and WDM networks. Later, he led research on WDM components (EDFAs, AWGs and fiber Fabry-Perot Filters), and on WDM local and wide area networks. He is a member of the National Academy of Engineering and a recipient of the IEEE/OSA John Tyndall, OSA Charles Townes and IEEE/LEOS Quantum Electronics Awards. Since 2004, he has been Adjunct Professor

关键词： Optical fiber communication. Optical fiber communication Equipment and supplies. Fiber optics. Telecommunication systems Management.

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Blockchain(Research and Applications) 2021年第3期2卷 68-78页

作者： Simona Ramos Fabio Pianese Thomas Leach Ester Oliveras Augmented Machine Interaction team AI Research LabNokia Bell LabsParis-SaclayNozay 91620France Department of Computer Science Universitat Pompeu FabraBarcelona 08002Spain Department of Economics Universita di PaviaPavia 27100Italy

A non-traditional type of financial asset,cryptocurrencies based on public blockchains are still little understood in their real-world *** events such as cyber-attacks and their media coverage can strongly affect their supply and demand,adoption and usage,efficiency,and infrastructural development,thus influencing their price stability and market *** the great technical complexity of blockchains,we believe that a pure economic analysis of risks associated with cryptocurrencies is simply not sufficient to convey the relationships between attacks and the disruptive effects that these can bring on the operation of *** these grounds,we survey the most common types of attacks for Proof-of-Work(PoW)cryptocurrencies and evaluate their impact on the returns of a number of real-world cryptocurrencies for which market data are *** to data availability,our event study analysis focuses on instances of 51% attacks,hard forks,and wallet *** main goal of our analysis is to understand the relationship between technical events(cyber-attacks and coordinated user/miner behavior)and the economic impacts surrounding *** aim to develop a deeper understanding of these systems that are objects of great research interest in separate disciplines,supporting policymakers in their regulatory decisions concerning crypto-assets and associated cyber-related financial risks.

关键词： Blockchain Cryptocurrencies Event studies Cyber attacks

Single-ended characterization of the coherent transfer matrix of coupled multimode transmission channels

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Photonics Research 2023年第10期11卷 1627-1634页

作者： ALIREZA FARDOOST FATEMEH GHAEDI VANANI SETHUMADHAVAN CHANDRASEKHAR GUIFANG LI CREOL The College of Optics and PhotonicsUniversity of Central FloridaOrlandoFlorida 32816USA Retired nokia bell labs Murray HillNew Jersey 07974USA

Light propagation in random media is a subject of interest to the optics community at large,with applications ranging from imaging to communication and ***,real-time characterization of wavefront distortion in random media remains a major *** the difficulties,for many applications such as imaging(e.g.,endoscopy)and focusing through random media,we only have single-ended *** this work,we propose to represent wavefronts as superpositions of spatial *** this framework,random media can be represented as a coupled multimode transmission *** the distributed coherent transfer matrix of the channel is characterized,wavefront distortions along the path can be ***,backreflections almost always accompany mode coupling and wavefront ***,we further propose to utilize backreflections to perform single-ended characterization of the coherent transfer *** first develop the general framework for single-ended characterization of the coherent transfer matrix of coupled multimode transmission ***,we apply this framework to the case of a two-mode channel,a single-mode fiber,which supports two randomly coupled polarization modes,to provide a proof-of-concept ***,as one of the main applications of coherent channel estimation,a polarization imaging system through singlemode fibers is *** envision that the proposed method can be applied to both guided and free-space channels with a multitude of applications.

关键词： polarization coherent characterization