This paper presented a novel semi blind adaptive beamforming algorithm specially designed for wideband coherent CDMA mobile communication systems with multiplexd control and data channels. The presented algorithm uses...This paper presented a novel semi blind adaptive beamforming algorithm specially designed for wideband coherent CDMA mobile communication systems with multiplexd control and data channels. The presented algorithm uses a parallel structure to exploit not only the desired user’s pseudo noise sequence but also the information from multiplexed pilot and data symbols, thus help achieve faster convergence and lower bit error rate. Monte Carlo simulation results verified the performance improvement in terms of BER.展开更多
Let ρ be a congruence on a semingroup S.ρis called a rectangular band congruence if S/ρ is a rectangular band. In this paper the least restangular band congruence on a senigroup is disccribed . Let T be a subsemi...Let ρ be a congruence on a semingroup S.ρis called a rectangular band congruence if S/ρ is a rectangular band. In this paper the least restangular band congruence on a senigroup is disccribed . Let T be a subsemigroup of a semigroup S. A necessary and sufficient condition for which every rectangular band congruence on T can be uniquely extended to a rectangular band congruence on S is given.展开更多
The atomic structure of quasi one-dimensional(1D) van der Waals materials can be regarded as the stacking of atomic chains to form thin flakes or nanoribbons, which substantially differentiates them from typical two-d...The atomic structure of quasi one-dimensional(1D) van der Waals materials can be regarded as the stacking of atomic chains to form thin flakes or nanoribbons, which substantially differentiates them from typical two-dimensional(2D) layered materials and 1D nanotube/nanowire array. Here we present our studies on quasi 1D gold selenide(AuSe) that possesses highly anisotropic crystal structure, excellent electrical conductivity, giant magnetoresistance, and unusual reentrant metallic behavior. The low inplane symmetry of AuSe gives rise to its high anisotropy of vibrational behavior. In contrast, quasi 1D AuSe exhibits high in-plane electrical conductivity along the directions of both atomic chains and perpendicular one, which can be understood as a result of strong interchain interaction. We found that AuSe exhibits a near quadratic nonsaturating giant magnetoresistance of 1841% with the magnetic field perpendicular to its in-plane. We also observe unusual reentrant metallic behavior, which is caused by the carrier mismatch in the multiband transport. Our works help to establish fundamental understandings on quasi 1D van der Waals semimetallic AuSe and identify it as a new candidate for exploring giant magnetoresistance and compensated semimetals.展开更多
文摘This paper presented a novel semi blind adaptive beamforming algorithm specially designed for wideband coherent CDMA mobile communication systems with multiplexd control and data channels. The presented algorithm uses a parallel structure to exploit not only the desired user’s pseudo noise sequence but also the information from multiplexed pilot and data symbols, thus help achieve faster convergence and lower bit error rate. Monte Carlo simulation results verified the performance improvement in terms of BER.
文摘Let ρ be a congruence on a semingroup S.ρis called a rectangular band congruence if S/ρ is a rectangular band. In this paper the least restangular band congruence on a senigroup is disccribed . Let T be a subsemigroup of a semigroup S. A necessary and sufficient condition for which every rectangular band congruence on T can be uniquely extended to a rectangular band congruence on S is given.
基金This work was supported by the Research Grant Council of Hong Kong(N_PolyU540/17)the Shenzhen Science and Technology Innovation Commission(JCYJ20180507183424383)the Hong Kong Polytechnic University(G-SB79 and G-YBPS).
文摘The atomic structure of quasi one-dimensional(1D) van der Waals materials can be regarded as the stacking of atomic chains to form thin flakes or nanoribbons, which substantially differentiates them from typical two-dimensional(2D) layered materials and 1D nanotube/nanowire array. Here we present our studies on quasi 1D gold selenide(AuSe) that possesses highly anisotropic crystal structure, excellent electrical conductivity, giant magnetoresistance, and unusual reentrant metallic behavior. The low inplane symmetry of AuSe gives rise to its high anisotropy of vibrational behavior. In contrast, quasi 1D AuSe exhibits high in-plane electrical conductivity along the directions of both atomic chains and perpendicular one, which can be understood as a result of strong interchain interaction. We found that AuSe exhibits a near quadratic nonsaturating giant magnetoresistance of 1841% with the magnetic field perpendicular to its in-plane. We also observe unusual reentrant metallic behavior, which is caused by the carrier mismatch in the multiband transport. Our works help to establish fundamental understandings on quasi 1D van der Waals semimetallic AuSe and identify it as a new candidate for exploring giant magnetoresistance and compensated semimetals.
