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:
Provided are an electrolyte comprising an amide compound of a specific structure, in which an alkoxy group is substituted with an amine group, and an ionizable lithium salt, and an electrochemical device containing the same. The electrolyte may have excellent thermal and chemical stability and a wide electrochemical window. Also, the electrolyte may have a sufficiently low viscosity and a high ionic conductivity, and thus, may be usefully applied as an electrolyte of electrochemical devices using various anode materials.
摘要:
An electrolyte includes an eutectic mixture composed of (a) a hetero cyclic compound having a predetermined chemistry figure, and (b) an ionizable lithium salt. An electrochemical device having the electrolyte. The eutectic mixture included in the electrolyte exhibits inherent characteristics of an eutectic mixture such as excellent thermal stability and excellent chemical stability, thereby improving the problems such as evaporation, ignition and side reaction of an electrolyte caused by the usage of existing organic solvents.
摘要:
Disclosed is a cooperative relay station that relays between a base station and a mobile station when retransmitting a signal. Also, disclosed is a base station that receives a signal from a mobile station in mutual cooperation with the cooperative relay station. After the cooperative relay station receives and decodes a signal that the mobile station transmits to the base station or a service relay station, if an error of the decoded signal does not exist, it stores the received signal. If an error occurs when the base station decodes the signal that the mobile station transmits, the base station requests retransmission for the signal with the error to the cooperative relay station. If the cooperative relay station gets a request of retransmission, it transmits the signal that the base station requests to the base station. In this was, since an error rate may be reduced when the base station requests retransmission of the signal, resource reuse efficiency may become improved, interference may be reduced, and it is easy to adapt to a service being sensitive to time delay.