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  • 121301.
    Zhang, Li
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, Philosophy.
    Hansson, Sven Ove
    KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, Philosophy.
    How to make up one's mind2015In: Logic journal of the IGPL (Print), ISSN 1367-0751, E-ISSN 1368-9894, Vol. 23, no 4, p. 705-717Article in journal (Refereed)
    Abstract [en]

    The operation of making up one's mind about a sentence phi is a belief change operation that takes the agent to a belief state in which either phi or phi is believed. Apart from being practically important, this operation is technically interesting since the standard approach of intersecting a set of optimal outcomes is not workable. A construction based on descriptor revision is provided in which the operation can be modelled. This construction is axiomatically characterized with a set of plausible postulates, and additional postulates that correlate with properties of the construction are investigated.

  • 121302.
    Zhang, Li
    et al.
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, Inst Artificial Photosynth, State Key Lab Fine Chem, 2 Linggong Rd, Dalian 116024, Peoples R China..
    Yang, Xichuan
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, Inst Artificial Photosynth, State Key Lab Fine Chem, 2 Linggong Rd, Dalian 116024, Peoples R China..
    Wang, Weihan
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, Inst Artificial Photosynth, State Key Lab Fine Chem, 2 Linggong Rd, Dalian 116024, Peoples R China..
    Gurzadyan, Gagik G.
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, Inst Artificial Photosynth, State Key Lab Fine Chem, 2 Linggong Rd, Dalian 116024, Peoples R China..
    Li, Jiajia
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, Inst Artificial Photosynth, State Key Lab Fine Chem, 2 Linggong Rd, Dalian 116024, Peoples R China..
    Li, Xiaoxin
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, Inst Artificial Photosynth, State Key Lab Fine Chem, 2 Linggong Rd, Dalian 116024, Peoples R China..
    An, Jincheng
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, Inst Artificial Photosynth, State Key Lab Fine Chem, 2 Linggong Rd, Dalian 116024, Peoples R China..
    Yu, Ze
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, Inst Artificial Photosynth, State Key Lab Fine Chem, 2 Linggong Rd, Dalian 116024, Peoples R China..
    Wang, Haoxin
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, Inst Artificial Photosynth, State Key Lab Fine Chem, 2 Linggong Rd, Dalian 116024, Peoples R China..
    Cai, Bin
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, Inst Artificial Photosynth, State Key Lab Fine Chem, 2 Linggong Rd, Dalian 116024, Peoples R China..
    Hagfeldt, Anders
    Ecole Polytech Fed Lausanne, Lab Photomol Sci, Inst Chem Sci & Engn, CH-1015 Lausanne, Switzerland..
    Sun, Licheng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry. Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, Inst Artificial Photosynth, State Key Lab Fine Chem, 2 Linggong Rd, Dalian 116024, Peoples R China.
    13.6% Efficient Organic Dye-Sensitized Solar Cells by Minimizing Energy Losses of the Excited State2019In: ACS ENERGY LETTERS, ISSN 2380-8195, Vol. 4, no 4, p. 943-951Article in journal (Refereed)
    Abstract [en]

    The electron-injection energy losses of dye-sensitized solar cells (DSSCs) are among the fundamental problems hindering their successful breakthrough application. Two triazatruxene (TAT)-based sensitizers, with one containing a flexible Z-type double bond and another a rigid single bond, coded as ZL001 and ZL003, respectively, have been synthesized and applied in DSSCs to probe the energy losses in the process of electron injection. Using time-resolved laser spectroscopic techniques in the kinetic study, ZL003 with the rigid single bond promotes much faster electron injection into the conductive band of TiO2 especially in the locally excited state (hot injection), which leads to higher electron density in TiO2 and a higher V-oc. The devices based on ZL003 exhibited a champion power conversion efficiency (PCE) of 13.6% with V-oc = 956 mV, J(sc) = 20.73 mA cm(-2), and FF = 68.5%, which are among the highest recorded results to date on single dye-sensitized DSSCs. An independent certified PCE of 12.4% has been obtained for devices based on ZL003.

  • 121303.
    Zhang, Liang
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology. VINNOVA Competence Ctr Adv Bioprod Continuous Pro, AdBIOPRO, Stockholm, Sweden..
    Castan, Andreas
    GE Healthcare Biosci AB, Bjorkgatan 30, S-75184 Uppsala, Sweden..
    Stevenson, Joanne
    Cobra Biol AB, Stockholm, Sweden..
    Chatzissavidou, Nathalie
    Cobra Biol AB, Stockholm, Sweden..
    Vilaplana, Francisco
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Chotteau, Veronique
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology. VINNOVA Competence Ctr Adv Bioprod Continuous Pro, AdBIOPRO, Stockholm, Sweden..
    Combined effects of glycosylation precursors and lactate on the glycoprofile of IgG produced by CHO cells2019In: Journal of Biotechnology, ISSN 0168-1656, E-ISSN 1873-4863, Vol. 289, p. 71-79Article in journal (Refereed)
    Abstract [en]

    The glycosylation profile of therapeutic monoclonal antibodies (mAbs) is a crucial quality parameter for industrial Immunoglobulin G (IgG) production. Several alternative carbon sources, which function as glycosylation precursors, have been reported to impact the glycosylation pattern. Since the cells give priority to glucose uptake, the presence of this substrate can lower the effects of alternative sugars on the glycosylation. In order to get a better understanding of the influence of alternative sugars on the glycosylation and to investigate how they impact each other, combinations of mannose, fructose, galactose and fucose were fed to Chinese hamster ovary (CHO) cells in batch culture when the glucose became depleted and the lactate, accumulated in the culture, was used as carbon source. Feeding with a feed containing mannose or glucose decreased by 3-7% the percentage of high mannose glycans compared to a feed without mannose or glucose. Feeding with a feed containing galactose led to 8-20% increase of monogalactoglycans (G1) glycans and 2-6% rise of digalactoglycans (G2) glycans compared to feeding without galactose or glucose. The cells fed with fucose exhibited a significantly higher concentration of intracellular GDP-Fucose. This work indicates that a feeding strategy based on non-glucose sugars and potentially lactate, could be adopted to obtain a targeted glycosylation profile.

  • 121304. Zhang, Liang
    et al.
    Fontana, Jacopo
    Bernhem, Kristoffer
    Nilsson, Linnéa
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biophysics.
    Scott, Lena
    Blom, Hans
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biophysics.
    Brismar, Hjalmar
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biophysics.
    Aperia, Anita
    Ouabain intervenes early in the apoptotic process by preventing BAD activationManuscript (preprint) (Other academic)
  • 121305. Zhang, Liang
    et al.
    Wang, Wujun
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Yu, Zitao
    Fan, Liwu
    Hu, Yacai
    Ni, Yu
    Fan, Jianren
    Cen, Kefa
    An experimental investigation of a natural circulation heat pipe system applied to a parabolic trough solar collector steam generation system2012In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 86, no 3, p. 911-919Article in journal (Refereed)
    Abstract [en]

    A U-type natural circulation heat pipe system is designed and applied to a parabolic trough solar collector for generating mid-temperature steam. Thermal performance of the heat pipe system is investigated experimentally. A detailed heat transfer analysis is performed on thermal behaviors of the system, especially the solar collector. The results show that the system can generate mid-temperature steam of a pressure up to 0.75 MPa. The thermal efficiency is found to be 38.52% at discharging pressure of 0.5 MPa during summer time.

  • 121306. Zhang, Liang
    et al.
    Yu, Zitao
    Fan, Liwu
    Wang, Wujun
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Chen, Huan
    Hu, Yacai
    Fan, Jianren
    Ni, Mingjiang
    Cen, Kefa
    An experimental investigation of the heat losses of a U-type solar heat pipe receiver of a parabolic trough collector-based natural circulation steam generation system2013In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 57, p. 262-268Article in journal (Refereed)
    Abstract [en]

    The performance of a parabolic trough collector (PTC)-based steam generation system depends significantly on the heat losses of the solar receiver. This paper presents an experimental study of the heat losses of a double glazing vacuum U-type solar receiver mounted in a PTC natural circulation system for generating medium-temperature steam. Field experiments were performed to determine the overall heat losses of the receiver. Effects of wind, vacuum glass tube, radiation, and structural characteristics on the heat losses were analyzed. The thermal efficiency of the receiver was found to be 0.791 and 0.472 in calm and windy days, respectively, at a test temperature of about 100 degrees C, whereas the thermal efficiencies became 0.792 and 0.663, respectively, while taking the receiver element into consideration. The heat losses were increased from 0.183 to 0.255 kW per receiver for the two cases tested. It was shown that neither convection nor radiation heat losses may be negligible in the analysis of such U-type solar receivers.

  • 121307.
    Zhang, Liao
    KTH, School of Electrical Engineering and Computer Science (EECS).
    5G Radio Measurements Analysis: Propagation property analysis at 3.5GHz around corners in Kista2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With the development of the next generation network, 5th-Generation Wireless systems (Abbreviated 5G), the demands to provide higher capacity and allow massive amount of user devices and sensors at a wide range of frequency bands are increasing. Exploring higher frequency bands is a good way to help find solutions to improve the capacity and data rate. Previously, researchers at Ericsson have analyzed radio wave propagation properties at 15/28GHz. However, there are still much weakness of higher frequencies like scattering, non-line-of-sight issues and etc. The difficulties to fix these problems leads to the continuous heavy rely on sub-6GHz spectrums. In this project, propagation characteristics at 3.5GHz, which is a typical frequency of the sub-6GHz frequency bands, are explored. By measuring the propagation model at 3.5GHz, the propagation properties can be well understood for better utilizing the spectrum.

    In this project, experiments are conducted in an urban scenario on Ericsson 5G Testbed. Channel estimation for each propagation path is acquired on the testbed. Power delay profiles are calculated according to the channel estimation. The measurements are compared with current propagation models, including knife-edge model, street canyon model and diffuse scattering model. The result shows that the measurements fit the models perfectly with several explainable variations. Suggestions for improving the current models are raised to make the model more practical.

  • 121308.
    Zhang, Lichang
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Non-invasive detection algorithm of thermal comfort based on computer vision2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The waste of building energy consumption is a major challenge in the world. And the real-time detection of human thermal comfort is an effective way to meet this issue. As mentioned in name, it means to detect the human’s comfort level in real-time and non-invasively. However, due to the various factors such as individual difference of thermal comfort, elements related to climatic (temperature, humidity, illumination, etc.) and so on, there is still a long way to implement this strategy in real life. From another perspective, the current HVAC (heating, ventilating and air-conditioning) systems cannot provide flexible interaction channels to adjust atmosphere, and naturally fails to satisfy requirements of users. All of them indicate the necessity to develop a detection method for human thermal comfort. In this paper, a non-invasion detection method toward human thermal comfort is proposed from two perspectives: macro human postures and skin textures. In posture part, OpenPose is used for analyzing the position coordinates of human body key points’ in images, for example, elbow, knee, and hipbone, etc. And the results of analyzing would be interpreted from the term of thermal comfort. In skin textures, deep neural network is used to predict the temperature of human skins via images. Based on Fanger’s theory of thermal comfort, the results of both parts are satisfying: subjects’ postures can be captured and interpreted into different thermal comfort level: hot, cold and comfort. And the absolute error of prediction from neurons network is less than 0.125 degrees centigrade which is the equipment error of thermometer used in data acquisition. With the solution proposed by this paper, it is promising to non-invasively detect the thermal comfort level of users from postures and skin textures. Finally, theconclusion and future work are discussed in final chapter.

  • 121309.
    Zhang, Lidong
    KTH, School of Electrical Engineering (EES), Electrical Machines and Power Electronics.
    Modeling and Control of VSC-HVDC Links Connected to Weak AC Systems2010Doctoral thesis, monograph (Other academic)
    Abstract [en]

    For high-voltage direct-current (HVDC) transmission, the strength of the ac system is important for normal operation. An ac system can be considered as weak either because its impedance is high or its inertia is low. A typical high-impedance systemis when an HVDC link is terminated at a weak point of a large ac system where the short-circuit capacity of the ac system is low. Low-inertia systems are considered to have limited number of rotating machines, or no machines at all. Examples of such applications can be found when an HVDC link is powering an isand system, or if it is connected to a wind farm. One of the advantages of applying a voltage-source converter (VSC) based HVDC systemis its potential to be connected to very weak ac systems where the conventional linecommutated converter (LCC) based HVDC system has difficulties.

    In this thesis, the modeling and control issues for VSC-HVDC links connected to weak ac systems are investigated. In order to fully utilize the potential of the VSC-HVDC system for weak-ac-system connections, a novel control method, i.e., powersynchronization control, is proposed. By using power-synchronization control, the VSC resembles the dynamic behavior of a synchronous machine. Several additional functions, such as high-pass current control, current limitation, etc. are proposed to deal with  issues during operation.

    For modeling of ac/dc systems, the Jacobian transfer matrix is proposed as a unified modeling approach. With the ac Jacobian transfer matrix concept, a synchronous ac system is viewed upon as one multivariable feedback system. In the thesis, it is shown that the transmission zeros and poles of the Jacobian transfer matrix are closely related to several power-system stability phenomena. The similar modeling concept is extended to model a dc system with multiple VSCs. It is mathematically proven that the dc system is an inherently unstable process, which requires feedback controllers to be stabilized.

    For VSC-HVDC links using power-synchronization control, the short-circuit ratio (SCR) of the ac system is no longer a limiting factor, but rather the load angles. The righthalf plane (RHP) transmission zero of the ac Jacobian transfer matrix moves closer to the origin with larger load angles, which imposes a fundamental limitation on the achievable bandwidth of the VSC. As an example, it is shown that a VSC-HVDC link using powersynchronization control enables a power transmission of 0.86 p.u. from a system with an SCR of 1.2 to a system with an SCR of 1.0. For low-inertia systemconnections, simulation studies show that power-synchronization control is flexible for various operation modes related to island operation and handles the mode shifts seamlessly.

  • 121310.
    Zhang, Lidong
    et al.
    ABB Power Systems.
    Harnefors, Lennart
    ABB Power Systems.
    Nee, Hans-Peter
    KTH, School of Electrical Engineering (EES), Electrical Machines and Power Electronics.
    Interconnection of Two Very Weak AC Systems by VSC-HVDC Links Using Power-Synchronization Control2011In: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 26, no 1, p. 344-355Article in journal (Refereed)
    Abstract [en]

    In this paper, voltage-source converter (VSC) based high-voltage dc (HVDC) transmission is investigated for interconnection of two very weak ac systems. By using the recently proposed power-synchronization control, the short-circuit capacities of the ac systems are no longer the limiting factors, but rather the load angles. For the analysis of the stability, the Jacobian transfer matrix concept has been introduced. The right-half plane (RHP) transmission zero of the ac Jacobian transfer matrix moves closer to the origin with larger load angles. The paper shows that, due to the bandwidth limitation imposed by the RHP zero on the direct-voltage control of the VSC, high dc-capacitance values are needed for such applications. In addition, the paper proposes a control structure particularly designed for weak-ac-system interconnections. As an example, it is shown that the proposed control structure enables a power transmission of 0.86 p.u. from a system with the short-circuit ratio (SCR) of 1.2 to a system with an SCR of 1.0. This should be compared to previous results for VSC based HVDC using vector current control. In this case, only 0.4 p.u. power transmission can be achieved for dc link where only one of the ac systems has an SCR of 1.0.

  • 121311. Zhang, Lidong
    et al.
    Harnefors, Lennart
    Nee, Hans-Peter
    KTH, School of Electrical Engineering (EES), Electrical Machines and Power Electronics.
    Modeling and Control of VSC-HVDC Links Connected to Island Systems2011In: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 26, no 2, p. 783-793Article in journal (Refereed)
    Abstract [en]

    The recently proposed power-synchronization control for grid-connected voltage-source converters (VSCs) has been shown to be a feasible solution for high-voltage direct-current (HVDC) transmission connected to high-impedance weak ac systems. In this paper, power-synchronization control is investigated for VSC-HVDC links connected to another type of weak ac system, i.e., low-inertia or island systems. As an example, a linear model of a typical island system feeding by a VSC-HVDC link, including a synchronous generator, an induction motor, and some passive loads, is developed for tuning the control parameters of the VSC-HVDC link. Time simulations in PSCAD/EMTDC demonstrate that VSC-HVDC systems using power-synchronization control are flexible for various network conditions, such as large-ac-system connection, island systems, or passive networks. The time simulations also show that power-synchronization control can seamlessly handle transitions between operation modes, as well as ride through ac-system faults in all network conditions.

  • 121312.
    Zhang, Lidong
    et al.
    ABB power Systems, Ludvika.
    Harnefors, Lennart
    ABB Power Systems, Ludvika.
    Nee, Hans-Peter
    KTH, School of Electrical Engineering (EES), Electrical Machines and Power Electronics (closed 20110930).
    Modelling and control of VSC-HVDC connected to island systems2010In: IEEE Power and Energy Society General Meeting, IEEE , 2010Conference paper (Refereed)
    Abstract [en]

    The recently proposed power-synchronization control for grid-connected voltage-source converters (VSCs) has been shown to be a feasible solution for high-voltage dc (HVDC) transmission connected to high-impedance weak ac systems. In this paper, power-synchronization control is investigated for VSC-HVDC connected to another type of weak ac system, i.e., low-inertia or island systems. As an example, a linear model of a typical island system feeding by a VSC-HVDC link, including a synchronous generator, an induction motor and some passive loads, is developed for tuning the control parameters of the VSCHVDC. Time simulations in PSCAD/EMTDC demonstrate that VSC-HVDC using power-synchronization control is flexible for various network conditions, such as large-ac-system connection, island systems, or passive networks. The time simulations also show that power-synchronization control can seamlessly handle transitions between the operation modes, as well as ride through ac-system faults in all network conditions.

  • 121313. Zhang, Lidong
    et al.
    Harnefors, Lennart
    Nee, Hans-Peter
    KTH, School of Electrical Engineering (EES), Electrical Machines and Power Electronics.
    Power-Synchronization Control of Grid-Connected Voltage-Source Converters2010In: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 25, no 2, p. 809-820Article in journal (Refereed)
    Abstract [en]

    In this paper, a novel control method of grid-connected voltage-source converters (VSCs) is proposed. The method can be generally applied for all grid-connected VSCs but may be of most importance in high-voltage dc (HVDC) applications. Different from the previous control methods, the proposed method utilizes the internal synchronization mechanism in ac systems, in principle, similar to the operation of a synchronous machine. By using this type of power-synchronization control, the VSC avoids the instability caused by a standard phase-locked loop in a weak ac-system connection. Moreover, a VSC terminal can give the weak ac system strong voltage support, just like a normal synchronous machine does. The control method is verified by both analytical models and time simulations.

  • 121314.
    Zhang, Lidong
    et al.
    ABB Power Systems, Ludvika.
    Nee, Hans-Peter
    KTH, School of Electrical Engineering (EES).
    Multivariable feedback design of VSC-HVDC connected to weak ac systems2009In: 2009 IEEE Bucharest PowerTech / [ed] IEEE, IEEE , 2009, p. 764-771Conference paper (Refereed)
    Abstract [en]

    Power-synchronization control is particularly applicable to voltage-source converters based high-voltage direct-current (HVDC) transmission connected to weak ac systems. In this paper, the multivariable feedback design aspect of the power-synchronization control is investigated by two design approaches: internal model control (IMC) and Hinfin control. The paper shows that both of the methods can meet the design requirements and show good robustness with different model uncertainties and load disturbances. The advantage of the IMC approach is that it provides a transparent framework for control-system design and tuning. The algorithm used for the IMC design in this paper is simple, yet it achieves similar or even better performance and robustness compared to the more advanced optimization-based Hinfin controller.

  • 121315.
    Zhang, Lidong
    et al.
    ABB Power Systems, Ludvika.
    Nee, Hans-Peter
    KTH, School of Electrical Engineering (EES).
    Harnefors, Lennart
    KTH, School of Electrical Engineering (EES).
    Analysis of Stability Limitations of a VSC-HVDC Link Using Power-Synchronization Control2011In: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 26, no 3, p. 1326-1337Article in journal (Refereed)
    Abstract [en]

    In this paper, the stability limitations are analyzed for a voltage-source converter (VSC) based high-voltage direct-current (HVDC) link using power-synchronization control for two feasible operation modes: alternating-voltage control and reactive-power control. As a comparison, the analysis has been done by the phasor approach and the space-vector approach. While the phasor approach is straightforward to apply and gives intuitive analytical results, the space-vector approach reflects more dynamic insights of the system. This is achieved by using a unified dynamic modeling of both the ac system and the VSC by means of a new introduced modeling approach Jacobian transfer matrices. This approach shows that non-minimum-phase phenomena due to competing effects between alternating voltages and currents following phase-angle changes impose a fundamental limitation on the achievable bandwidth of the VSC-HVDC link. At moderate voltage levels, a VSC-HVDC link operating in alternating-voltage control mode is able to achieve higher bandwidth than in reactive-power control mode since the right-half plane (RHP) zero is located further from the origin in the former mode.

  • 121316.
    Zhang, Liming
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Chemical structure of condensed tannins from 8 different tree species studied by NMR techniques2011In: 16th International Symposium on Wood, Fiber and Pulping Chemistry: Proceedings, ISWFPC, Tianjin, China, 2011, p. 93-97Conference paper (Refereed)
    Abstract [en]

    NMR techniques were applied to study and to compare the chemical structure of tannins from 8 different tree species, i.e., Norway spruce (Picea abies), Scots pine (Pinus sylvestris), larch (Larix gmelini), French maritime pine bark extractive, Quebracho (Schinopsis lorentzii), black wattle (Acacia mearnsii), Mangium (Acacia mangium) and Chinese Bayberry tree (Myrica rubra). The tannins from Norway spruce bark and Scots pine bark were extracted in our laboratory by using fresh bark harvested in Stockholmarea. The other tannins were obtained as commercial samples. It was found in this study that the complicated chemical structures of condensed tannins can be elucidated by applying 13C, DEPT90, and 2D HSQC NMR techniques. The tannins from pines and larch were found to be structurally similar to each other, containing mainly the procyanidins. In the case of Norway spruce tannin, stilbene polymer or stilbene- procyanidin co-polymer were found to comprise about half of the tannin content together with procyanidins. Quebracho tannin was found to contain predominantly the profisetinidins, in agreement with results of other earlier studies. Black wattle tannin was also found to contain profisetinidins as the major components, and proanthocyanidins and probably prorobinetinidins as the minor components. Tannin from Mangium was found to contain the prorobinetinidins as the major components. The Chinese Bayberry (Myrica rubra) tannin, however was found to contain mainly the prorobinetinidins and also small amount of the prodelphinidins.

  • 121317.
    Zhang, Liming
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Gellerstedt, Göran
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    2D Heteronuclear (1H-13C) Single Quantum Correlation (HSQC) NMR Analysis of Norway Spruce Bark Components2009In: Characterization of Lignocellulosic Materials, Blackwell Publishing, 2009, p. 1-16Chapter in book (Refereed)
    Abstract [en]

    Norway spruce (Picea abies) bark, collected during the winter and summer seasons, has been separated into inner- and outer-bark fractions followed by extraction using a fivesolvent extraction procedure. The inner-bark fraction was found to contain a rather high amount of carbohydrates but only minor amounts of tannin. In addition, the glucosides of stilbenes such as astringin and isorhapontin were detected. The outer-bark fraction had a high content of high-molecular-mass tannin but was low in carbohydrates. Lignin-derived components were also detected. Further studies of the tannin fraction using advanced nuclear magnetic resonance (NMR) techniques showed that polyflavanol and polystilbene units together with glucoside units were prevalent.

  • 121318.
    Zhang, Liming
    et al.
    KTH, Superseded Departments, Pulp and Paper Technology.
    Gellerstedt, Göran
    KTH, Superseded Departments, Pulp and Paper Technology.
    NMR observation of a new lignin structure, a spiro-dienone2001In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, no 24, p. 2744-2745Article in journal (Refereed)
    Abstract [en]

    A spiro-dienone structure (eta -1/alpha -O-alpha) has been observed as one of the important structures present in spruce and aspen lignins, with abundance as high as 3% in spruce lignin.

  • 121319.
    Zhang, Liming
    et al.
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Gellerstedt, Göran
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Qualitative and quantitative study of lignin structure by applying highresolution 2D HSQC NMR technique2004In: 2nd International Symposium on Technologies Of Pulping, Papermaking and Biotechnology on Fiber Plants, Proceedings / [ed] Jin, YC; Xie, HF, NANJING: NANJING FORESTRY UNIV , 2004, p. 88-92Conference paper (Refereed)
    Abstract [en]

    High-resolution 2D HSQC NMR technique was found to be a powerful analytical tool for studies on lignin structure. High resolution in the F1 dimension of an HSQC spectrum can be obtained by proper sample purification and optimized shimming as well as by acquiring large enough increments. By combining the results from 2D HSQC, HSQC-TOCSY and HMBC NMR experiments, novel lignin structures, including spiro-dienone, secoisolariciresinol and neo-olivil have been observed and identified. The concept of quantitative structure determination by applying 2D HSQC NMR technique was investigated. The influence of T-2 relaxation decays, coupling constant, off-resonance effect and homonuclear couplings on NMR signal quantification have been discussed. beta-5 Structure in a lignin sample was accurately determined by using the HSQC NMR analysis through a unique way of selecting the proper internal standard reference signal(s).

  • 121320.
    Zhang, Liming
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Gellerstedt, Göran
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Quantitative 2D HSQC NMR determination of polymer structures by selecting suitable internal standard references2007In: Magnetic Resonance in Chemistry, ISSN 0749-1581, E-ISSN 1097-458X, Vol. 45, no 1, p. 37-45Article in journal (Refereed)
    Abstract [en]

    A new analytical method based on the 2D HSQC NMR sequence is presented, which can be applied for quantitative structural determination of complicated polymers. The influence of T-1 and T-2 relaxations, off-resonance effects, coupling constants and homonuclear couplings are discussed. It was found that the T-2 values measured on polymeric samples with the conventional HSQC-CPMG sequence could not be used to correct the errors caused by T-2 relaxations during the polarization transfer delay. A unique way of selecting the proper internal standard reference signal(s) is therefore proposed to eliminate the major errors caused by T-2 relaxations, resonance offsets, coupling constant deviations and homonuclear couplings. Two polymer samples, a cellulose triacetate and an acetylated lignin, have been used to illustrate the principles. The methodology developed in this work is robust to instrument miss-setting and it can find wide-spread applications in areas where a quantitative analysis of structurally complicated polymers is necessary.

  • 121321.
    Zhang, Liming
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Gellerstedt, Göran
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Ralph, J.
    Lu, F. C.
    NMR studies on the occurrence of spirodienone structures in lignins2006In: Journal of wood chemistry and technology, ISSN 0277-3813, E-ISSN 1532-2319, Vol. 26, no 1, p. 65-79Article in journal (Refereed)
    Abstract [en]

    Spirodienone structures have been detected in spruce, birch, and kenaf lignin isolates. NMR signals corresponding to guaiacyl and syringyl spirodienones were fully identified and assigned based on C-13, QUAT, HSQC, HSQC-TOCSY, and HMBC NMR data. Spruce lignin contains spirodienone structures of the guaiacyl type. Syringyl spirodienones dominate in kenaf and birch lignins. Each type of spirodienone was found to be present in two different stereoisomeric forms, with one of the isomers being more prevalent. Signal integrations indicate that about three spirodienones per 100 phenylpropanoid units are present in the spruce and birch lignins and about four in the kenaf lignin.

  • 121322.
    Zhang, Liming
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Gellerstedt, Göran
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Svensson-Rundlöf, E.
    Zhang, E.
    Behavior of chromophoric structures in softwood TMP during H 2O2 bleaching2005In: Appita Annual Conference, Vol 2, Australia: Appita, Inc. , 2005, p. 299-302Conference paper (Refereed)
    Abstract [en]

    A commercial TMP and an isolated lignin from the TMP (milled pulp lignin, or MPL) were treated with alkaline H2O2 bleaching as well as with several other specially designed chemical reactions. Analyses with NMR indicated that coniferaldehyde structures were eliminated completely from the lignin polymer by H2O2 bleaching. Phenolic content was found to have little impact on the final brightness of the TMP sample. Significant amounts of vanillin units (∼4%) were stable towards alkaline H2O2 bleaching and they remained in the TMP lignin after H2O2 bleaching. Even though the lignin sample was completely dissolved during the bleaching treatment, full brightness could not be achieved with the alkaline H2O2 bleaching treatment alone irrespective of the H2O2 charges being used, indicating that physical hindrance was less likely to be an important factor causing the brightness ceiling. It was probably the presence of certain H 2O2-resistant chromophores in the unbleached TMP that limited the further brightness improvement of the TMP at a certain brightness level. The bulk of the polymeric lignin structure seemed to be stable towards alkaline H2O2. The total coniferaldehyde and vanillin units present in the lignin polymer can only account for part of the H 2O2 consumed (not more than 10 kg/ton) during the bleaching process. The predominant reaction responsible for the consumption of H2O2 during the bleaching process was found to be the formation of carboxylic acid groups.

  • 121323.
    Zhang, Liming
    et al.
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Henriksson, Gunnar
    KTH, Superseded Departments, Pulp and Paper Technology.
    Gellerstedt, Göran
    KTH, Superseded Departments, Pulp and Paper Technology.
    The formation of beta-beta structures in lignin biosynthesis - are there two different pathways?2003In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 1, no 20, p. 3621-3624Article in journal (Refereed)
    Abstract [en]

    Based on results from 2D NMR studies, both pinoresinol and secoisolariciresinol structures were found to be present in native lignin from spruce wood as well as in spruce kraft lignin and residual kraft pulp lignin. These two structures constitute the major types of beta-beta inter-unit linkages present in spruce lignin, but their formation in the lignin polymer may follow different pathways leading to their different bonding patterns with the rest of the lignin polymer. The mechanisms involved are discussed.

  • 121324. Zhang, Lin
    et al.
    Kang, Zheng-Zhong
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. Zhejiang Univ, Dept Chem, Zheda Rd 38, Hangzhou 310027, Zhejiang, Peoples R China.
    Qi, Shi-Chao
    Liu, Xiao-Qin
    Wang, Zhi-Min
    Sun, Lin-Bing
    Ultradeep Removal of Moisture in Gases to Parts-per-Billion Levels: The Exploration of Adsorbents2018In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, no 5, p. 2840-2847Article in journal (Refereed)
    Abstract [en]

    Owing to the rigid standards of manufacturing semiconductor components, decrease of the moisture to parts-per-billion (ppb), at a global level, is always vital but extremely nerve-racking in the production of high-purity gases. Herein, typical adsorbents including oxides (SiO2 and gamma-Al2O3), zeolites (4A and NaX), and metal-organic frameworks (MOFs; HKUST-1, UiO-66, and ZIF-8) are investigated with respect to the abilities of ultradeep dewatering from N-2. Compared with other adsorbents, NaX performs much better on both dewatering efficiency (DE, from 2750 to 66 ppb) and the adsorption capacity (AC, 1.55 x 10(4) L N-2.g(-1)). Moreover, it is for the first time experimentally and theoretically proved that the dewatering ability of X zeolite mainly depends on its cation species (Na+, Li+, K+, Cs+, Mg2+, Ca2+, Sr2+, or Ba2+), the forces between the zeolite and H2O, and the number of H2O molecules per cell of the zeolite. CaX thus shows a fascinating DE from 2750 to 33 ppb, a huge AC of 9.08 x 10(4) L N-2.g(-1), and an ideal reusability, compared with results of the scarce contributions reported to date.

  • 121325. Zhang, Lin
    et al.
    Liu, Jiaqi
    Xiao, Ming
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre. KTH, School of Electrical Engineering (EES), Information Science and Engineering.
    Wu, Gang
    Liang, Ying-Chang
    Li, Shaoqian
    Performance Analysis and Optimization in Downlink NOMA Systems With Cooperative Full-Duplex Relaying2017In: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 35, no 10, p. 2398-2412Article in journal (Refereed)
    Abstract [en]

    We study a downlink non-orthogonal multiple access system with cooperative full-duplex relaying, where the near user in terms of the base station (BS) is enabled to act as a full-duplex relay for the far user. In particular, we first derive the outage probability and ergodic sum rate with closed-form expressions when the power allocations at the BS and relay (or the near user) are fixed. Then, we analytically obtain the optimal power allocations with closed-form expressions at the BS and relay to minimize the outage probability. Furthermore, by taking the fairness between the near user and far user into account, we characterize the optimal power allocations with closed-form expressions at the BS and relay to maximize the minimum achievable rate of users. Simulation results validate the correctness of the theoretical analysis and demonstrate the advantages of the proposed algorithms over the state of the art.

  • 121326. Zhang, Lin
    et al.
    Wang, Zhao
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Xiao, Ming
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Wu, Gang
    Order-Optimal Caching in Hierarchical Networks2016In: 2016 IEEE/CIC INTERNATIONAL CONFERENCE ON COMMUNICATIONS IN CHINA (ICCC), IEEE, 2016Conference paper (Refereed)
    Abstract [en]

    The decentralized caching is studied in hierarchical networks, where users request contents through intermediate nodes (helpers) from a file server. By placing contents randomly and independently in each node and carefully designing the data delivery, the correlations of the pre-stored contents across layers can be utilized to reduce the transmission rate in each layer. A hybrid caching scheme is developed by exploiting the cross-layer storage correlations as well as the single-layer and cross-layer multicast opportunities. It is observed that the achievable rate region of the hybrid caching scheme is strictly better than the caching scheme in [1]. Furthermore, the order-optimality of the hybrid caching scheme is demonstrated by achieving the performance within constant multiplicative and additive factors of the information-theoretic optimum. In particular, the multiplicative and additive factors are carefully quantified to be 1/48 and 4, respectively.

  • 121327.
    Zhang, Lin
    et al.
    Univ Elect Sci & Technol China, Key Lab Commun, Chengdu 611731, Sichuan, Peoples R China.;Univ Elect Sci & Technol China, Ctr Intelligent Networking & Commun, Chengdu 611731, Sichuan, Peoples R China..
    Wang, Zhao
    Ericsson Res, S-16483 Stockholm, Sweden..
    Xiao, Ming
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering. KTH Royal Inst Technol, Sch Elect Engn, S-11428 Stockholm, Sweden..
    Wu, Gang
    Univ Elect Sci & Technol China, Key Lab Commun, Chengdu 611731, Sichuan, Peoples R China..
    Liang, Ying-Chang
    Univ Elect Sci & Technol China, Ctr Intelligent Networking & Commun, Chengdu 611731, Sichuan, Peoples R China..
    Li, Shaoqian
    Univ Elect Sci & Technol China, Key Lab Commun, Chengdu 611731, Sichuan, Peoples R China..
    Decentralized Caching Schemes and Performance Limits in Two-Layer Networks2018In: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 67, no 12, p. 12177-12192Article in journal (Refereed)
    Abstract [en]

    We study the decentralized caching scheme in a two-layer network, which includes a server, multiple helpers, and multiple users. Basically, the proposed caching scheme consists of two phases, i.e., placement phase and delivery phase. In the placement phase, each helper/user randomly and independently selects contents from the server and stores them into its memory. In the delivery phase, the users request contents from the server, and the server satisfies each user through a helper. Different from the existing caching scheme, the proposed caching scheme takes into account the pre- stored contents at both helpers and users in the placement phase to design the delivery phase. Meanwhile, the proposed caching scheme exploits index coding in the delivery phase and leverages multicast opportunities, even when different users request distinct contents. Besides, we analytically characterize the performance limit of the proposed caching scheme, and show that the achievable rate region of the proposed caching scheme lies within constant margins to the information-theoretic optimum. In particular, the multiplicative and additive factors are carefully sharpened to be 1/48 and 4, respectively, both of which are better than the state of arts. Finally, simulation results demonstrate the advantage of the proposed caching scheme compared with the state of arts.

  • 121328.
    Zhang, Lin
    et al.
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu, Sichuan, Peoples R China..
    Xiao, Ming
    KTH, School of Electrical Engineering (EES). Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu, Sichuan, Peoples R China.
    Liu, Jiaqi
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu, Sichuan, Peoples R China..
    Wu, Gang
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu, Sichuan, Peoples R China..
    Lin, Dengsheng
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu, Sichuan, Peoples R China..
    Li, Shaoqian
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu, Sichuan, Peoples R China..
    Outage Probability Analysis and Optimization in Downlink NOMA Systems with Cooperative Full-duplex Relaying2017In: 2017 IEEE 86th Vehicular Technology Conference (VTC-FALL), Institute of Electrical and Electronics Engineers (IEEE), 2017, Vol. 2017, p. 1-5Conference paper (Refereed)
    Abstract [en]

    We study a downlink non-orthogonal multiple access (NOMA) system with cooperative full-duplex relaying, where the near user in terms of the base station (BS) is enabled to act as a full-duplex relay for the far user. In particular, we first derive the outage probability with closed-form expressions when the power allocations at the BS and relay (or the near user) are fixed. Then, we analytically obtain the optimal power allocations with closed-form expressions at the BS and relay to minimize the outage probability. Numerical results validate the correctness of the theoretical analysis and demonstrate the advantages of the proposed algorithms over the state of arts.

  • 121329. Zhang, Lin
    et al.
    Xiao, Ming
    KTH, School of Electrical Engineering (EES), Information Science and Engineering.
    Wu, Gang
    Alam, Muhammad
    Liang, Ying-Chang
    Li, Shaoqian
    A SURVEY OF ADVANCED TECHNIQUES FOR SPECTRUM SHARING IN 5G NETWORKS2017In: IEEE wireless communications, ISSN 1536-1284, E-ISSN 1558-0687, Vol. 24, no 5, p. 44-51Article in journal (Refereed)
    Abstract [en]

    Spectrum efficiency is one of the key performance metrics in 5G communication networks. To enhance spectrum efficiency, advanced spectrum sharing techniques are normally used. In this article, we provide a survey of the recent development of advanced techniques for spectrum sharing. In particular, we elaborate cognitive radio, device-to-device communication, in-band full-duplex communication, non-orthogonal multiple access, and Long Term Evolution on unlicensed spectrum. For each technique, we present the basic principle and research methodology of the state of the art. By considering various promising evolutions in 5G networks, we emphasize challenges to deploy each technique. Finally, we discuss the integration issue of multiple spectrum sharing techniques and identify potential challenges.

  • 121330. Zhang, Lin
    et al.
    Xiao, Ming
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Wu, Gang
    Li, Shaoqian
    Efficient Scheduling and Power Allocation for D2D-Assisted Wireless Caching Networks2016In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 64, no 6, p. 2438-2452Article in journal (Refereed)
    Abstract [en]

    We study a one-hop device-to-device (D2D)-assisted wireless caching network, where popular files are randomly and independently cached in the memory of end users. Each user may obtain the requested files from its own memory without any transmission, or from a helper through a one-hop D2D transmission, or from the base station. We formulate a joint D2D link scheduling and power allocation problem to maximize the system throughput. However, the problem is non-convex, and obtaining an optimal solution is computationally hard. Alternatively, we decompose the problem into a D2D link-scheduling problem and an optimal power allocation problem. To solve the two subproblems, we first develop a D2D link-scheduling algorithm to select the largest number of D2D links satisfying both the signal to interference plus noise ratio and the transmit power constraints. Then, we develop an optimal power allocation algorithm to maximize the minimum transmission rate of the scheduled D2D links. Numerical results indicate that both the number of the scheduled D2D links and the system throughput can be improved simultaneously with the Zipf-distribution caching scheme, the proposed D2D link-scheduling algorithm, and the proposed optimal power allocation algorithm compared with the state of the arts.

  • 121331. Zhang, Lin
    et al.
    Xiao, Ming
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Wu, Gang
    Li, Shaoqian
    Liang, Ying-Chang
    Energy-Efficient Cognitive Transmission With Imperfect Spectrum Sensing2016In: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 34, no 5, p. 1320-1335Article in journal (Refereed)
    Abstract [en]

    We investigate the energy efficiency (EE) in cognitive radio networks, where cognitive users are allowed to access a licensed frequency band opportunistically, provided that the licensed band is vacant. In particular, we study the impact of imperfect spectrum sensing and formulate the average EE maximization problem in fading channels as a joint optimization problem of the spectrum sensing duration and the transmit power of cognitive users. Meanwhile, we consider the constraints of both the collision probability between the primary and cognitive transmissions and the outage probability of cognitive transmissions. However, the joint optimization problem subject to the constraints is complicated and it is computationally hard to obtain the optimal solution. Alternatively, we develop two algorithms, i.e., a linear search algorithm and an iterative-based algorithm, with considerable complexity to solve the problem. Numerical results verify the correctness of both algorithms and show that the proposed algorithms can achieve the performance close to that of the exhaustive search algorithm and outperform the state of arts.

  • 121332. Zhang, Lin
    et al.
    Xiao, Ming
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Wu, Gang
    Zhao, Guodong
    Liang, Ying-Chang
    Li, Shaoqian
    Proactive Cross-Channel Gain Estimation for Spectrum Sharing in Cognitive Radio2016In: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 34, no 10, p. 2776-2790Article in journal (Refereed)
    Abstract [en]

    In an underlay cognitive radio network, the cross-channel gain from a cognitive transmitter (CT) to a primary receiver (PR) is crucial for spectrum sharing. By exploiting the relaying capability of the CT, we propose a proactive estimation scheme for the cross-channel gain. Specifically, the CT proactively acts as a full-duplex amplify-and-forward (AF) relay for primary transceivers to trigger the power adaption of a primary transmitter (PT). By carefully designing the relay signal, the CT is able to obtain an estimation of the cross-channel gain by observing the power adaption. To demonstrate the accuracy of the estimation, we analytically characterize both an upper bound and a lower bound of the estimation performance. Furthermore, we study the impact of CT's relaying on the primary transmission and observe that the impact is related to the CT's location. By introducing a factor phi (0 <= phi <= 1) to denote the probability that the CT's relaying improves the primary transmission instead of causes interference, we design the CT location as a function of f. Numerical results show that the estimation error of the proactive estimation scheme can be as small as 1.7% with success estimation probability around 91%. By comparing with the state of the art, we show the advantages of the proposed estimator.

  • 121333. Zhang, Ling
    et al.
    Kim, Hyung Joon
    Nadig, Vinay
    Ismail, Mohammed
    A 1.8 V tri-mode Sigma Delta modulator for GSM/WCDMA/WLAN wireless receiver2006In: Analog Integrated Circuits and Signal Processing, ISSN 0925-1030, E-ISSN 1573-1979, Vol. 49, no 3, p. 323-341Article in journal (Refereed)
    Abstract [en]

    The next generation of cellular systems will be increasingly similar to a data communication system. Not only will it transfer voice and multimedia data, it will also be integrated with WLAN to access Internet whenever possible. Thus these cellular systems need highly integrated multi-standard receivers. The design of the A/D converter in such receivers is a big challenge. A GSM/WCDMA/WLAN tri-mode receiver is first designed on the system level. A reconfigurable Sigma Delta modulator, which is suitable for GSM/WCDMA/WLAN receiver, is then proposed in this paper. According to the different signal bandwidth and Dynamic Range (DR) specifications, this Sigma Delta modulator is reconfigured to achieve the required dynamic range with less power consumption. The prototype is implemented in TSMC 0.18-mu m CMOS process with 1.8 V power supply. The circuit achieves signal-to-noise-and-distortion-ratio of 82 dB for GSM, 75 dB for WCDMA and 58 dB for WLAN.

  • 121334.
    Zhang, Linlin
    et al.
    Dalian University of Technology, China.
    Gao, Y.
    Dalian University of Technology, China.
    Liu, Z.
    Dalian University of Technology, China.
    Ding, X.
    Dalian University of Technology, China.
    Yu, Z.
    Dalian University of Technology, China.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. Dalian University of Technology, China.
    A trinuclear ruthenium complex as a highly efficient molecular catalyst for water oxidation2016In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 45, no 9, p. 3814-3819Article in journal (Refereed)
    Abstract [en]

    A trinuclear ruthenium complex, 3, was designed and synthesized with the ligand 2,2'-bipyridine-6,6'-dicarboxylic acid (bda) and we found that this complex could function as a highly efficient molecular catalyst for water oxidation in homogeneous systems. This trinuclear molecular water oxidation catalyst, 3, displayed much higher efficiencies in terms of turnover numbers and initial oxygen evolution rate than its counterparts, a binuclear catalyst, 2, and a mononuclear catalyst, 1, in both chemically driven and photochemically driven water oxidation based on either the whole catalytic molecules or just the active Ru centers. The reasons for the superior performance of catalyst 3 were discussed and we believe that multiple Ru centers in a single molecule are indeed beneficial for increasing the probability of the formation of O-O bonds through an intramolecular radical coupling pathway.

  • 121335. Zhang, Linlin
    et al.
    Gao, Yan
    Ding, Xin
    Yu, Ze
    Sun, Licheng
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. State Key Laboratory of Fine Chemicals, Institute of Artificial Photosynthesis, DUT-KTH Joint Education and Research Center on Molecular Devices, Dalian University of Technology (DUT), China.
    High-Performance Photoelectrochemical Cells Based on a Binuclear Ruthenium Catalyst for Visible-Light-Driven Water Oxidation2014In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 7, no 10, p. 2801-2804Article in journal (Refereed)
    Abstract [en]

    Two photoanodes based on a binuclear (2) and a mononuclear ruthenium (3) water oxidation catalysts were assembled in combination with a molecular photosensitizer (1) by using a co-adsorption method. The anodes were used in dye-sensitized photoelectrochemical cells (DS-PECs) for visible-light-driven water splitting. A DS-PEC device using TiO2(1+2) as working electrode (WE) exhibits better performance than TiO2(1+3) as WE in light-driven water splitting. Detailed photoelectrochemical studies on these DS-PEC devices are discussed.

  • 121336. Zhang, Linus
    et al.
    Gustafsson, David
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Editorial: 'The Nordic Hydrology Model' - Linking science and practice2016In: Hydrology Research, ISSN 1998-9563, Vol. 47, no 4, p. 671-671Article in journal (Refereed)
  • 121337.
    Zhang, Liyang
    KTH, School of Electrical Engineering (EES).
    Real-time Coding for Kinesthetic and Tactile Signals2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Tactile Internet is at the core of the 5G era, when the world will experience paradigm shift from content-delivery networks to service/labour-delivery ones. Systems that enable wireless communications of haptic data feature bi-directionality, high packet rate and resolution, large degrees of freedom, and above all, strict latency requirements in many applications, aggravating the shortage of wireless resources. Thus, more efficient haptic data reduction techniques are continuously summoned for. Previous studies  on haptic compression mostly resort to DPCM/ADPCM plus entropy coding and perception-based down-sampling for real-time scenarios, and model-based techniques such as DCT and LP for the rest. However, with few exceptions they always segregate tactile signals from kinaesthetic signals, employing only kinaesthetic feedbacks in real-time compression experiments. In addition, these techniques are not optimized for efficient performance at scale. This thesis project proposes a novel multi-channel real-time haptic compression system aimed at teleoperation applications with both kinaesthetic and tactile feedbacks. It consists of a lossy compression layer featuring predictive coding and a lossless layer featuring channel reshuffle and group transmission. By using different quantizer designs in the lossy layer, it abates the need for entropy coding, and leave room for future perception-based data compression modules. The lossless layer exploits inter-channel sparsity for further data reduction. The system is evaluated on a tactile texture database published by University of Pennsylvania in MATLAB. The performance measurements are in both time and frequency domain, mostly objective, but include subjective considerations as well.

  • 121338.
    Zhang, Liyang
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Yan, Min
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Qiu, Min
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    The effect of transformation order on the invisibility performance of a practical cylindrical cloak2008In: Journal of Optics. A, Pure and applied optics, ISSN 1464-4258, E-ISSN 1741-3567, Vol. 10, no 9Article in journal (Refereed)
    Abstract [en]

    A class of polynomial coordinate transformation functions with an arbitrary order number is used to design cylindrical invisibility cloaks. Since an ideal cylindrical cloak is inevitably unphysical at its inner boundary, our investigation involves the replacement of a thin layer of material at the cloak's inner surface by a homogeneous material layer. This approach effectively avoids the infinities in the material parameters, and at the same time produces practical near-ideal invisibility cloaks. The cloaks obtained are perfectly matched in impedance at the outer boundary. We quantitatively show the effect of the transformation order on the proposed cloak's scattering coefficients.

  • 121339.
    Zhang, Long
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Theoretical Computer Science, TCS.
    Monperrus, Martin
    KTH.
    TripleAgent: Monitoring, Perturbation And Failure-obliviousness for Automated Resilience Improvement in Java ApplicationsManuscript (preprint) (Other academic)
    Abstract [en]

    In this paper, we present a novel system for fault injection in production for Java applications. The unique feature of this system is to combine automated monitoring, automated perturbation injection, and automated resilience improvement. The latter is achieved with ideas coming from the failure-oblivious literature. We design and implement the system as agents for the Java virtual machine. We evaluate the system on a real-world application for transferring files with the BitTorrent protocol. Our results shows that it is possible to automatically improve the resilience of Java applications with respect to uncaught exceptions.

  • 121340.
    Zhang, Long
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Theoretical Computer Science, TCS.
    Morin, Brice
    Haller, Philipp
    Baudry, Benoit
    Monperrus, Martin
    A Chaos Engineering System for Live Analysis and Falsification of Exception-handling in the JVMManuscript (preprint) (Other academic)
    Abstract [en]

    Software systems contain resilience code to handle those failures and unexpected events happening in production. It is essential for developers to understand and assess the resilience of their systems. Chaos engineering is a technology that aims at assessing resilience and uncovering weaknesses by actively injecting perturbations in production. In this paper, we propose a novel design and implementation of a chaos engineering system in Java called CHAOSMACHINE. It provides a unique and actionable analysis on exception-handling capabilities in production, at the level of try-catch blocks. To evaluate our approach, we have deployed CHAOSMACHINE on top of 3 large-scale and well-known Java applications totaling 630k lines of code. Our results show that CHAOSMACHINE reveals both strengths and weaknesses of the resilience code of a software system at the level of exception handling.

  • 121341.
    Zhang, Lu
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab). Shanghai Jiao Tong Univ, State Key Lab Adv Opt Commun Syst & Networks, Shanghai 200240, Peoples R China..
    Chen, Jiajia
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Urban, Patryk J.
    Ericsson AB, Ericsson Res, S-16483 Stockholm, Sweden..
    Xiao, Shilin
    Shanghai Jiao Tong Univ, State Key Lab Adv Opt Commun Syst & Networks, Shanhai 200240, Peoples R China..
    Hu, Weisheng
    Shanghai Jiao Tong Univ, State Key Lab Adv Opt Commun Syst & Networks, Shanhai 200240, Peoples R China..
    Fixed and Mobile Convergence with Stacked Modulation2018In: 22ND INTERNATIONAL CONFERENCE ON OPTICAL NETWORK DESIGN AND MODELING (ONDM 2018) / [ed] Ruffini, M Tzanakaki, A Casellas, R Autenrieth, A MarquezBarja, JM, IEEE , 2018, p. 36-40Conference paper (Refereed)
    Abstract [en]

    We propose a stacked modulation mechanism to realize the transmission convergence of fixed broadband and wireless access networks. As an integrated solution, the direct current biased analog signal for wireless data is multiplied by the digital optical signal carrying fixed broadband service, where the low-speed analog signal becomes an envelope of the high-speed digital signal. At the receiver, the analog signal is firstly recovered with the image edge detection algorithm, after which the digital signal is recovered with the least-square algorithm. This scheme can realize fixed and mobile convergence with a single wavelength, which reduces the access network cost in terms of number of transceivers. Besides, the link capacity and spectrum efficiency are also improved. Moreover, this method is compatible with the existing access networks since the transceivers can be adopted to the scenario by turning off the unused modules. Simulation results show that in case of intensity modulation direct detection system sensitivity, penalty of only 1 similar to 2 dB can be obtained for the 10Gbps/lambda passive optical network when broadband access services are favored. Meanwhile, the wireless service needs more power than the broadband service to achieve the QoT requirements, and it has a higher penalty (similar to 5 dB) compared with broadband access services.

  • 121342.
    Zhang, Lu
    et al.
    KTH, School of Information and Communication Technology (ICT). State Key Laboratory of Advanced Optical Communication System and Networks, Shanghai Jiao Tong University, Shanghai 200240, China.
    Hong, Xuezhi
    KTH, School of Information and Communication Technology (ICT). MOE International Laboratory for Optical Information Technologies, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China.
    Pang, Xiaodan
    KTH, School of Information and Communication Technology (ICT). Networking and Transmission Laboratory, RISE Acreo AB, Kista 16425, Sweden.
    Ozolins, Oskars
    Udalcovs, Aleksejs
    Schatz, Richard
    KTH, School of Engineering Sciences (SCI), Applied Physics, Optics and Photonics, OFO.
    Guo, Changjian
    Zhang, Junwei
    Nordwall, Fredrik
    Engenhardt, Klaus M.
    Westergren, Urban
    KTH, School of Engineering Sciences (SCI), Applied Physics, Optics and Photonics, OFO.
    Popov, Sergei
    KTH, School of Engineering Sciences (SCI), Applied Physics, Optics and Photonics, OFO.
    Jacobsen, Gunnar
    Xiao, Shilin
    Hu, Weisheng
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab). MOE International Laboratory for Optical Information Technologies, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China.
    Nonlinearity-aware 200 Gbit/s DMT transmission for C-band short-reach optical interconnects with a single packaged electro-absorption modulated laser2018In: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 43, no 2, p. 182-185Article in journal (Refereed)
    Abstract [en]

    We experimentally demonstrate the transmission of a 200 Gbit/s discrete multitone (DMT) at the soft forward error correction limit in an intensity-modulation directdetection system with a single C-band packaged distributed feedback laser and traveling-wave electro absorption modulator (DFB-TWEAM), digital-to-analog converter and photodiode. The bit-power loaded DMT signal is transmitted over 1.6 km standard single-mode fiber with a net rate of 166.7 Gbit/s, achieving an effective electrical spectrum efficiency of 4.93 bit/s/Hz. Meanwhile, net rates of 174.2 Gbit/s and 179.5 Gbit/s are also demonstrated over 0.8 km SSMF and in an optical back-to-back case, respectively. The feature of the packaged DFB-TWEAM is presented. The nonlinearity-aware digital signal processing algorithm for channel equalization is mathematically described, which improves the signal-to-noise ratio up to 3.5 dB. 

  • 121343.
    Zhang, Lu
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Ozolins, O.
    Lin, Rui
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Udalcovs, Aleksejs
    Pang, Xiaodan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Gan, L.
    Schatz, Richard
    KTH, School of Engineering Sciences (SCI), Applied Physics, Photonics.
    Djupsjobacka, A.
    Martensson, J.
    Westergren, Urban
    KTH, School of Engineering Sciences (SCI), Applied Physics, Photonics.
    Tang, M.
    Fu, S.
    Liu, D.
    Tong, W.
    Popov, Sergei
    KTH, School of Engineering Sciences (SCI), Applied Physics, Photonics.
    Jacobsen, G.
    Hu, W.
    Xiao, S.
    Chen, Jiajia
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Kernel Adaptive Filtering for Nonlinearity-Tolerant Optical Direct Detection Systems2018In: European Conference on Optical Communication, ECOC, Institute of Electrical and Electronics Engineers Inc. , 2018Conference paper (Refereed)
    Abstract [en]

    Kernel adaptive filtering (KAF) is proposed for nonlinearity-tolerant optical direct detection. for 7× 128 Gbit/s PAM4 transmission over 33.6km 7-core-fiber, KAF only needs 10 equalizer taps to reach KP4-FEC limit (BER@2.2e-4), whereas decision-feedback-equalizer needs 43 equalizer taps to reach HD-FEC limit (BER@3.8e-3).

  • 121344.
    Zhang, Lu
    et al.
    KTH. Shanghai Jiao Tong University, China.
    Pang, Xiaodan
    KTH. RISE Acreo AB, Sweden.
    Ozolins, O.
    Udalcovs, A.
    Popov, Sergei
    KTH.
    Xiao, S.
    Chen, Jiajia
    KTH.
    K-means clustering based multi-dimensional quantization scheme for digital mobile fronthaul2018In: Optics InfoBase Conference Papers, Optics Info Base, Optical Society of America, 2018Conference paper (Refereed)
    Abstract [en]

    We propose to group highly-correlated neighboring samples into multi-dimensional vectors and adopt k-means clustering for quantization in mobile fronthaul. 30-Gbit/s transmissions have been experimentally demonstrated for up to 40 100MHz LTE channels over 20km fiber.

  • 121345.
    Zhang, Lu
    et al.
    KTH, School of Information and Communication Technology (ICT). Shanghai Jiao Tong University, Shanghai, China.
    Pang, Xiaodan
    KTH, School of Information and Communication Technology (ICT). RISE Acreo AB, Kista, Sweden.
    Ozolins, O.
    Udalcovs, A.
    Schatz, Richard
    KTH, School of Information and Communication Technology (ICT).
    Westergren, Urban
    KTH, School of Information and Communication Technology (ICT).
    Jacobsen, G.
    Popov, Sergei
    KTH, School of Information and Communication Technology (ICT).
    Xiao, S.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT).
    15-Gbaud PAM4 Digital Mobile Fronthaul with Enhanced Differential Pulse Coding Modulation Supporting 122 LTE-A Channels with up to 4096QAM2018In: 2017 European Conference on Optical Communication (ECOC), Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 1-3Conference paper (Refereed)
    Abstract [en]

    By employing enhanced DPCM, 15-Gbaud PAM4 digital mobile fronthaul is experimentally demonstrated to support 122 LTE-A channels with up to 4096QAM. Compared to PCM based CPRI, the supported number of channels increases 5 times and EVM is obviously improved.

  • 121346.
    Zhang, Lu
    et al.
    KTH. Shanghai Jiao Tong Univ, State Key Lab Adv Opt Commun Syst & Networks, Shanghai, Peoples R China..
    Pang, Xiaodan
    KTH. KTH Royal Inst Technol, Stockholm, Sweden.;RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Ozolins, Oskars
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Udalcovs, Aleksejs
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Popov, Sergei
    KTH.
    Xiao, Shilin
    Shanghai Jiao Tong Univ, State Key Lab Adv Opt Commun Syst & Networks, Shanghai, Peoples R China..
    Chen, Jiajia
    KTH.
    K-means Clustering based Multi-Dimensional Quantization Scheme for Digital Mobile Fronthaul2018In: 2018 Optical Fiber Communications Conference and Exposition, OFC 2018 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2018Conference paper (Refereed)
    Abstract [en]

    We propose to group highly-correlated neighboring samples into multi-dimensional vectors and adopt k-means clustering for quantization in mobile fronthaul. 30-Gbit/s transmissions have been experimentally demonstrated for up to 40 100MHz LTE channels over 20km fiber.

  • 121347.
    Zhang, Lu
    et al.
    KTH. Shanghai Jiao Tong University, Shanghai, China.
    Pang, Xiaodan
    KTH. RISE Acreo AB, Networking & Transmiss Lab, S-16425 Kista, Sweden.
    Ozolins, Oskars
    Udalcovs, Aleksejs
    Popov, Sergei
    Xiao, Shilin
    Hu, Weisheng
    Chen, Jiajia
    KTH. South China Normal Univ, South China Acad Adv Optoelect, MOE Int Lab Opt Informat Technol, Guangzhou 510006, Guangdong, Peoples R China.
    Spectrally efficient digitized radio-over-fiber system with k-means clustering-based multidimensional quantization.2018In: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 43, no 7, p. 1546-1549Article in journal (Refereed)
    Abstract [en]

    We propose a spectrally efficient digitized radio-over-fiber (D-RoF) system by grouping highly correlated neighboring samples of the analog signals into multidimensional vectors, where the k-means clustering algorithm is adopted for adaptive quantization. A 30  Gbit/s D-RoF system is experimentally demonstrated to validate the proposed scheme, reporting a carrier aggregation of up to 40 100 MHz orthogonal frequency division multiplexing (OFDM) channels with quadrate amplitude modulation (QAM) order of 4 and an aggregation of 10 100 MHz OFDM channels with a QAM order of 16384. The equivalent common public radio interface rates from 37 to 150  Gbit/s are supported. Besides, the error vector magnitude (EVM) of 8% is achieved with the number of quantization bits of 4, and the EVM can be further reduced to 1% by increasing the number of quantization bits to 7. Compared with conventional pulse coding modulation-based D-RoF systems, the proposed D-RoF system improves the signal-to-noise-ratio up to ∼9  dB and greatly reduces the EVM, given the same number of quantization bits.

  • 121348.
    Zhang, Lu
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab). State Key Laboratory of Advanced Optical Communication System and Networks, Shanghai Jiao Tong University, Shanghai, China.
    Pang, Xiaodan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab). Networking and Transmission Laboratory, RISE Acreo AB, Kista, Sweden.
    Ozolins, Oskars
    Udalcovs, Aleksejs
    Schatz, Richard
    KTH, School of Engineering Sciences (SCI).
    Westergren, Urban
    KTH, School of Engineering Sciences (SCI).
    Jacobsen, Gunnar
    Popov, Sergei
    KTH, School of Engineering Sciences (SCI).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Xiao, Shilin
    Hu, Weisheng
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Digital mobile fronthaul employing differential pulse code modulation with suppressed quantization noise2017In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 25, no 25, p. 31921-31936Article in journal (Refereed)
    Abstract [en]

    A differential pulse code modulation (DPCM) based digital mobile fronthaul architecture is proposed and experimentally demonstrated. By using a linear predictor in the DPCM encoding process, the quantization noise can be effectively suppressed and a prediction gain of 7 similar to 8 dB can be obtained. Experimental validation is carried out with a 20 km 15-Gbaud/lambda 4-level pulse amplitude modulation (PAM4) intensity modulation and direct detection system. The results verify the feasibility of supporting 163, 122, 98, 81 20-MHz 4, 16, 64, 256 QAM based antenna-carrier (AxC) containers with only 3, 4, 5, 6 quantization bits at a sampling rate of 30.72MSa/s in LTE-A environment. Further increasing the number of quantization bits to 8 and 9, 1024 quadrature amplitude modulation (1024 QAM) and 4096 QAM transmission can be realized with error vector magnitude (EVM) lower than 1% and 0.5%, respectively. The supported number of AxCs in the proposed DPCM-based fronthaul is increased and the EVM is greatly reduced compared to the common public radio interface (CPRI) based fronthaul that uses pulse code modulation. Besides, the DPCM-based fronthaul is also experimentally demonstrated to support universal filtered multicarrier signal that is one candidate waveform for the 5th generation mobile systems.

  • 121349.
    Zhang, Lu
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Rodriguez, Saul
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Tenhunen, Hannu
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Zheng, Li-Rong
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    An innovative fully printable RFID technology based on high speed time-domain reflections2006In: 2006 Conference on High Density Microsystem Design and Packaging and Component Failure Analysis (HDP '06), Proceedings, 2006, p. 148-152Conference paper (Refereed)
    Abstract [en]

    In this paper, we present an innovative, chipless and fully printable RFID technology. The proposed tag is a fully passive device. Neither power supply nor. chip assembly is required. In our design, information data is embedded in the tag as impedance mismatches along a transmission line. The RFID-reader sends a short time pulse modulated at high frequencies. The reflections due to the impedance mismatches in the tag are transmitted back and detected by the reader. A prototype of the tag has been constructed and tested. The idea has been successfully proven both by simulations and experimental measurements.

  • 121350.
    Zhang, Lu
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Udalcovs, Aleksejs
    Lin, Rui
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Ozolins, Oskars
    Pang, Xiaodan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Gan, L.
    Schatz, Richard
    KTH, Superseded Departments (pre-2005), Electronics. KTH, Superseded Departments (pre-2005), Microelectronics and Information Technology, IMIT. KTH, School of Engineering Sciences (SCI), Applied Physics, Photonics.
    Djupsjöbacka, A.
    Mårtensson, J.
    Tang, M.
    Fu, S.
    Liu, D.
    Tong, W.
    Popov, Sergei
    KTH, School of Engineering Sciences (SCI), Applied Physics, Photonics.
    Jacobsen, Gunnar
    Hu, W.
    Xiao, S.
    Chen, Jiajia
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Digital Radio-Over-Multicore-Fiber System with Self-Homodyne Coherent Detection and Entropy Coding for Mobile Fronthaul2018In: European Conference on Optical Communication, ECOC, Institute of Electrical and Electronics Engineers Inc. , 2018Conference paper (Refereed)
    Abstract [en]

    We experimentally demonstrate a 28-Gbaud 16-QAM self-homodyne digital radio-over-33.6km-7-core-fiber system with entropy coding for mobile fronthaul, achieving error-free carrier aggregation of 330 100-MHz 4096-QAM 5G-new-radio channels and 921 100-MHz QPSK 5G-new-radio channels with CPRI-equivalent data rate up to 3.73-Tbit/s.

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