Large Scale multiple input multiple output(MIMO) systems have recently emerged as a promising technology for 5G communications.While they have been shown to offer significant performance benefits in theoretical studie...Large Scale multiple input multiple output(MIMO) systems have recently emerged as a promising technology for 5G communications.While they have been shown to offer significant performance benefits in theoretical studies,the large scale MIMO transmitters will have to be deployed in the limited physical space of today's base stations(BSs).Accordingly,this paper examines effects of deploying increasing numbers of antennas in fixed physical space,by reducing the antenna spacing.We focus on the resulting performance of large-scale MIMO transmitters using low complexity closed form precoding techniques.In particular,we investigate the combined effect of reducing the distance between the antenna elements with increasing the number of elements in a fixed transmitter space.This gives rise to two contradicting phenomena:the reduction of spatial diversity due to reducing the separation between antennas and the increase in transmit diversity by increasing the number of elements.To quantify this tradeoff,we investigate densely deployed uniform antenna arrays modelled by detailed electromagnetic simulation.Our results show the somewhat surprising result that,by reducing the separations between the antennas to significantly less than the transmit wavelength to fit more antennas,the resulting system performance improves.展开更多
The Chinese intelligence input technology, its applications, and a customer service call center system are developed. This technology can be used both in standard English telephone number input keyboard and in Chinese...The Chinese intelligence input technology, its applications, and a customer service call center system are developed. This technology can be used both in standard English telephone number input keyboard and in Chinese telephone number input keyboard .And authors develop sophisticated technologies including "Pinyin" (the Chinese phonetic alphabet ) encoding technology of phonetic symbol code and formal symbol code of Chinese character structure, phrase encoding technology, input technology of whole sentence intelligence encoding and input technology of Chinese telephone number encoding.展开更多
基金supported by the Royal Academy of Engineering,UKthe Seventh Framework Programme for Research of the European Commission under grant number HARP-318489
文摘Large Scale multiple input multiple output(MIMO) systems have recently emerged as a promising technology for 5G communications.While they have been shown to offer significant performance benefits in theoretical studies,the large scale MIMO transmitters will have to be deployed in the limited physical space of today's base stations(BSs).Accordingly,this paper examines effects of deploying increasing numbers of antennas in fixed physical space,by reducing the antenna spacing.We focus on the resulting performance of large-scale MIMO transmitters using low complexity closed form precoding techniques.In particular,we investigate the combined effect of reducing the distance between the antenna elements with increasing the number of elements in a fixed transmitter space.This gives rise to two contradicting phenomena:the reduction of spatial diversity due to reducing the separation between antennas and the increase in transmit diversity by increasing the number of elements.To quantify this tradeoff,we investigate densely deployed uniform antenna arrays modelled by detailed electromagnetic simulation.Our results show the somewhat surprising result that,by reducing the separations between the antennas to significantly less than the transmit wavelength to fit more antennas,the resulting system performance improves.
文摘The Chinese intelligence input technology, its applications, and a customer service call center system are developed. This technology can be used both in standard English telephone number input keyboard and in Chinese telephone number input keyboard .And authors develop sophisticated technologies including "Pinyin" (the Chinese phonetic alphabet ) encoding technology of phonetic symbol code and formal symbol code of Chinese character structure, phrase encoding technology, input technology of whole sentence intelligence encoding and input technology of Chinese telephone number encoding.
