摘要:
Provided are a virtual multi-antenna method for an orthogonal frequency division multiplexing (OFDM) system and an OFDM-based cellular system. The virtual multi-antenna method includes grouping sub-carriers in a frequency domain of an OFDM symbol and generating at least one group including G sub-carriers; and regarding the G sub-carriers included in the at least one group as multiple channels used in a multi-antenna technique and virtually applying the multi-antenna technique to the transmission and reception of the OFDM symbol. The virtual multi-antenna method can effectively reduce an interference signal and obtain the effects of a spatial division multiple access (SDMA) technique without physically using multiple antennas.
摘要:
The present invention relates to a transmitter in a frequency division multiple access communication system. The transmitter generates a plurality of pilot symbols, and groups the plurality of pilot symbols into a plurality of groups according to a location of a subcarrier. In addition, the transmitter inverse fast Fourier transforms the pilot symbol in each group, and sequentially outputs a first pilot symbol sequence corresponding to each group. The transmitter generates a plurality of pilot blocks respectively corresponding to the plurality of groups, and converts the first pilot symbol sequence of each group into a second pilot symbol sequence of a corresponding pilot block among the plurality of pilot blocks.
摘要:
A communication resource allocation method for solving resource request imbalance content in a cell is provided. Considering a propagation environment, the base station allocates a whispering resource to a whispering area, the whispering resource being one part of the communication resource and the whispering area being a peripheral area of the first base station, and allocates a speaking resource to a speaking area, the speaking resource being other parts of the communication resource and the speaking area being a border area of a cell. When the resource request of the whispering area is increased, the base station further allocates a part of the speaking resource to the whispering area or increases a ratio of the whispering resource. When the resource request of the speaking area is increased, the base station controls a threshold value for identifying the whispering and speaking areas or increases a ratio of the speaking resource.
摘要:
Disclosed are a base station, a relay station, and a terminal according to a method for designing a cellular system for improving resource usage efficiency by reducing interference between relay stations and interference between the base station and the relay station. The relay station gets control signals that terminals served by the base station transmit, and registers terminals, levels of the control signals of which are bigger than a predetermined value, to a list of the interference terminals. The relay station checks an interference resource through resource allocation information of the base station, checks an available resource corresponding to a resource except the interference resource among a resource allocated by the base station, and allocates some of the available resource to the terminal.
摘要:
Disclosed are a base station, a relay station, and a terminal according to a method for designing a cellular system for improving resource usage efficiency by reducing interference between relay stations and interference between the base station and the relay station. The relay station gets control signals that terminals served by the base station transmit, and registers terminals, levels of the control signals of which are bigger than a predetermined value, to a list of the interference terminals. The relay station checks an interference resource through resource allocation information of the base station, checks an available resource corresponding to a resource except the interference resource among a resource allocated by the base station, and allocates some of the available resource to the terminal.
摘要:
The present invention relates to a transmitter in a frequency division multiple access communication system. The transmitter generates a plurality of pilot symbols, and groups the plurality of pilot symbols into a plurality of groups according to a location of a subcarrier. In addition, the transmitter inverse fast Fourier transforms the pilot symbol in each group, and sequentially outputs a first pilot symbol sequence corresponding to each group. The transmitter generates a plurality of pilot blocks respectively corresponding to the plurality of groups, and converts the first pilot symbol sequence of each group into a second pilot symbol sequence of a corresponding pilot block among the plurality of pilot blocks.
摘要:
A communication resource allocation method for solving resource request imbalance content in a cell is provided. Considering a propagation environment, the base station allocates a whispering resource to a whispering area, the whispering resource being one part of the communication resource and the whispering area being a peripheral area of the first base station, and allocates a speaking resource to a speaking area, the speaking resource being other parts of the communication resource and the speaking area being a border area of a cell. When the resource request of the whispering area is increased, the base station further allocates a part of the speaking resource to the whispering area or increases a ratio of the whispering resource. When the resource request of the speaking area is increased, the base station controls a threshold value for identifying the whispering and speaking areas or increases a ratio of the speaking resource.
摘要:
Disclosed is an electrolyte comprising (a) a eutectic mixture of an amide compound represented by the following chemical formula 1 or 2 and an ionizable lithium salt; and (b) a nitrile compound. The eutectic mixture and the nitrile compound in the electrolyte contribute to excellent thermal and chemical stability and sufficiently low viscosity and high ion conductivity. The electrolyte can be usefully applied as an electrolyte of electrochemical devices.
摘要:
An electrolyte includes a eutectic mixture comprising (a) an alkoxy alkyl group-containing amide compound having a specific chemistry formula 1 or 2: wherein each of X, R, R1, R2, m and n is defined; and (b) an ionizable lithium salt. The eutectic mixture-containing electrolyte exhibits excellent high temperature stability as well as inherent characteristics of eutectic mixtures, including excellent thermal and chemical stability, thus contributing to improved high temperature stability and decreased lowest limit of electrochemical window. The electrolyte is useful in electrochemical devices comprising various anode materials.
摘要:
Disclosed is a non-aqueous electrolyte solution for a lithium secondary battery. The non-aqueous electrolyte solution includes a lithium salt, an organic solvent and additives. The additives include: 1 to 10% by weight of a mixture of a particular halogenated cyclic carbonate and a compound containing a vinylene or vinyl group; and 0.1 to 9% by weight of a nitrile compound having a C2-C12 alkoxyalkyl group. A lithium secondary battery including the non-aqueous electrolyte solution is also disclosed. The lithium secondary battery is protected from catching fire when overcharged and is prevented from swelling during storage at high temperature.