Compared with conventional multiple-input multiple-output(MIMO),massive MIMO system with tens or even hundreds of antennas is able to give better performance in capacity and spectral efficiency,which is a promising te...Compared with conventional multiple-input multiple-output(MIMO),massive MIMO system with tens or even hundreds of antennas is able to give better performance in capacity and spectral efficiency,which is a promising technology for 5G.Considering this,massive MIMO has become a hot research topic all over the world.In this paper,the channel measurements and models of massive MIMO in recent years are summarized.Besides,the related 256 antenna elements with 200 MHz bandwidth at 3.5 GHz proposed by our team,the verification of rationality of the measurement method,and the spatial evolution of clusters in mobile scenario are provided.展开更多
Descartes' metaphysical doubts in the Third and Fifth Meditations present a scenario like this: it is possible that I (the Meditator) am so imperfect as to be deceived by my author (i.e., an omnipotent God/Decei...Descartes' metaphysical doubts in the Third and Fifth Meditations present a scenario like this: it is possible that I (the Meditator) am so imperfect as to be deceived by my author (i.e., an omnipotent God/Deceiver) in the matters which I think I perceive clearly and distinctly. The metaphysical doubts attempt to cast doubt on beliefs based on present or recollected clear and distinct perceptions. This paper clarifies the intension of the metaphysical doubts by answering the question of how an omnipotent God/Deceiver might exercise a deceptive influence on clear and distinct perception. My analysis shows: (1) the memory interpretation and the retrospective interpretation to be implausible; (2) the incoherence interpretation to be ill-founded, though its conclusion is partly right, such that we should accept a weaker version of it; (3) the misrepresentation interpretation, the defective-origin interpretation, the truth-value variation interpretation and the radical interpretation to be plausible; (4) all of these credible interpretations to be compatible with each other as well.展开更多
基金supported in part by National Natural Science Foundation of China(61322110,6141101115)in part by National Science and Technology Major Project of the Ministry of Science and Technology(2015ZX03002008)+2 种基金in part by National Key Technology Research and Development Program(2012BAF14B01)“863”Program(2015AA01A703)Doctoral Fund of Ministry of Education(201300051100013).
文摘Compared with conventional multiple-input multiple-output(MIMO),massive MIMO system with tens or even hundreds of antennas is able to give better performance in capacity and spectral efficiency,which is a promising technology for 5G.Considering this,massive MIMO has become a hot research topic all over the world.In this paper,the channel measurements and models of massive MIMO in recent years are summarized.Besides,the related 256 antenna elements with 200 MHz bandwidth at 3.5 GHz proposed by our team,the verification of rationality of the measurement method,and the spatial evolution of clusters in mobile scenario are provided.
文摘Descartes' metaphysical doubts in the Third and Fifth Meditations present a scenario like this: it is possible that I (the Meditator) am so imperfect as to be deceived by my author (i.e., an omnipotent God/Deceiver) in the matters which I think I perceive clearly and distinctly. The metaphysical doubts attempt to cast doubt on beliefs based on present or recollected clear and distinct perceptions. This paper clarifies the intension of the metaphysical doubts by answering the question of how an omnipotent God/Deceiver might exercise a deceptive influence on clear and distinct perception. My analysis shows: (1) the memory interpretation and the retrospective interpretation to be implausible; (2) the incoherence interpretation to be ill-founded, though its conclusion is partly right, such that we should accept a weaker version of it; (3) the misrepresentation interpretation, the defective-origin interpretation, the truth-value variation interpretation and the radical interpretation to be plausible; (4) all of these credible interpretations to be compatible with each other as well.