The use of repeater for the support of high rate data trans- mission and the extension of cell coverage is imperative for the Wibro system, which based on the IEEE 802.16e standardization. Generally, if the separation...The use of repeater for the support of high rate data trans- mission and the extension of cell coverage is imperative for the Wibro system, which based on the IEEE 802.16e standardization. Generally, if the separation between transmitting and receiving antennas is not sufficient, the oscillation of repeater and the interference due to the feedback signals from original transmitted signal may be oectLrr. Hence, the Interference Cancellation System （ICS） should be implemented as the important part of the repeater system for the mobile cellular systems in order to eliminate unwanted signals from the corrupted signals in the receiver. In this paper, we propose an adaptive technique for the Least Mean Square（LMS）-based interference cancellation methods by changing the step size according to the variation of channel envirorauent in onter to improve the performance degradation which occta-rs by using the fixed step size approach. Simulation results show that the proposed scheme attains a little lower Ber Error Rate（BER） performance and much faster convergence speed compared to the conventional LMS-based interference cancellation techniques. The proposed scheme can be applied to other Orthogonal Frequency Division Multiple（OFDM）-based cellular systenas and also be expected to achieve a similar performance improvement to IMT-advanced system, which is called as the next generation mobile communication standards.展开更多
We study an anyon model in a toric honeycomb lattice. The ground states and the low-lying excitations coincide with those of Kitaev toric code model and then the excitations obey mutual semionic statistics. This model...We study an anyon model in a toric honeycomb lattice. The ground states and the low-lying excitations coincide with those of Kitaev toric code model and then the excitations obey mutual semionic statistics. This model is helpful to understand the toric code of anyons in a more symmetric way. On the other hand, there is a direct relation between this toric honeycomb model and a boundary coupled Ising chain array in a square lattice via Jordan-Wigner transformation. We discuss the equivalence between these two models in the low-lying sector and realize these anyon excitations in a conventional fermion system. The analysis for the ground state degeneracy in the last section can also be thought of as a complementarity of our previous work [Phys. A： Math. Theor. 43 （2010） 105306].展开更多
Modulating the oxidation states of transition metal species has been regarded as a promising strategy to tune the redox activity and achieve more active sites in electrode materials.In this work,a unique three-dimensi...Modulating the oxidation states of transition metal species has been regarded as a promising strategy to tune the redox activity and achieve more active sites in electrode materials.In this work,a unique three-dimensional(3D)honeycomb-like cobalt sulfide(Co_(x)S_(y))network organized by cross-linked nanosheets(Co_(x)S_(y)-T NSs)was prepared via a simple triethanolamine(TEOA)-assisted self-templating strategy.Interestingly,it has been found for the first time that the introduction of TEOA in the reaction effectively increases the ratio of high-valence Co^(3+)in the final product.Benefiting from the synergetic effect of the tailored high-valence Co^(3+)with the 3D network structure,the Co_(x)S_(y)-T NS electrode exhibits a maximum specific capacity of 351 mA h g^(-1)(2635 F g^(-1))at 5 A g^(-1)as well as excellent cycling stability.Furthermore,with the solid-state asymmetric supercapacitor(ASC)constructed based on the Co_(x)S_(y)-T NSs and activated carbon(AC)electrodes,a high energy density up to 81.62 W h kg^(-1)has been achieved at the power density of 0.81 kW kg^(-1)and 96.2%capacitance is preserved after 7000 cycles,indicating robust cycling stability.This result highlights the simple approach of simultaneously tailoring highvalence metal species and constructing 3D network structure toward high-performance electrode materials for energy storage and conversion.展开更多
基金supported bythe IT R&D Programof MKE/ⅡTA:Development of Service Platform for Next Generation Mobile Communications
文摘The use of repeater for the support of high rate data trans- mission and the extension of cell coverage is imperative for the Wibro system, which based on the IEEE 802.16e standardization. Generally, if the separation between transmitting and receiving antennas is not sufficient, the oscillation of repeater and the interference due to the feedback signals from original transmitted signal may be oectLrr. Hence, the Interference Cancellation System （ICS） should be implemented as the important part of the repeater system for the mobile cellular systems in order to eliminate unwanted signals from the corrupted signals in the receiver. In this paper, we propose an adaptive technique for the Least Mean Square（LMS）-based interference cancellation methods by changing the step size according to the variation of channel envirorauent in onter to improve the performance degradation which occta-rs by using the fixed step size approach. Simulation results show that the proposed scheme attains a little lower Ber Error Rate（BER） performance and much faster convergence speed compared to the conventional LMS-based interference cancellation techniques. The proposed scheme can be applied to other Orthogonal Frequency Division Multiple（OFDM）-based cellular systenas and also be expected to achieve a similar performance improvement to IMT-advanced system, which is called as the next generation mobile communication standards.
基金Supported by National Natural Science Foundation of Chinathe National Program for Basic Research of MOST of Chinathe Key Lab of Frontiers in Theoretical Physics of CAS and a Fund From CAS
文摘We study an anyon model in a toric honeycomb lattice. The ground states and the low-lying excitations coincide with those of Kitaev toric code model and then the excitations obey mutual semionic statistics. This model is helpful to understand the toric code of anyons in a more symmetric way. On the other hand, there is a direct relation between this toric honeycomb model and a boundary coupled Ising chain array in a square lattice via Jordan-Wigner transformation. We discuss the equivalence between these two models in the low-lying sector and realize these anyon excitations in a conventional fermion system. The analysis for the ground state degeneracy in the last section can also be thought of as a complementarity of our previous work [Phys. A： Math. Theor. 43 （2010） 105306].
基金the National Natural Science Foundation of China(21671173)Zhejiang Provincial Ten Thousand Talent Program(2017R52043)。
文摘Modulating the oxidation states of transition metal species has been regarded as a promising strategy to tune the redox activity and achieve more active sites in electrode materials.In this work,a unique three-dimensional(3D)honeycomb-like cobalt sulfide(Co_(x)S_(y))network organized by cross-linked nanosheets(Co_(x)S_(y)-T NSs)was prepared via a simple triethanolamine(TEOA)-assisted self-templating strategy.Interestingly,it has been found for the first time that the introduction of TEOA in the reaction effectively increases the ratio of high-valence Co^(3+)in the final product.Benefiting from the synergetic effect of the tailored high-valence Co^(3+)with the 3D network structure,the Co_(x)S_(y)-T NS electrode exhibits a maximum specific capacity of 351 mA h g^(-1)(2635 F g^(-1))at 5 A g^(-1)as well as excellent cycling stability.Furthermore,with the solid-state asymmetric supercapacitor(ASC)constructed based on the Co_(x)S_(y)-T NSs and activated carbon(AC)electrodes,a high energy density up to 81.62 W h kg^(-1)has been achieved at the power density of 0.81 kW kg^(-1)and 96.2%capacitance is preserved after 7000 cycles,indicating robust cycling stability.This result highlights the simple approach of simultaneously tailoring highvalence metal species and constructing 3D network structure toward high-performance electrode materials for energy storage and conversion.
