Abstract:
An apparatus and method for transmitting/receiving data in a closed-loop multi-antenna system. A receiver receives a plurality of data streams from a plurality of transmit antennas of a transmitter, generates Channel Quality Information (CQIs) of channels that carry data streams transmitted from at least two transmit antenna allocated to the receiver among the plurality of transmit antennas, and transmits the CQIs to the transmitter. For the CQI generation, the receiver generates a channel matrix through channel estimation of the received data streams, generates a reception beamforming matrix from the channel matrix including only components of the data streams transmitted from the allocated transmit antennas, and calculates the CQIs using the channel matrix, the reception beamforming matrix, and a total signal-to-noise ratio (SNR) obtained through the channel estimation.
Abstract:
A method for transmitting/receiving feedback information in a multi-antenna system using a closed-loop scheme supporting multiple users, and a feedback system supporting the same. Multiple feedback protocol scenarios are predefined on the basis of communication environments affecting feedback information configurations. The feedback information is transmitted in a feedback protocol scenario determined by a communication environment. The feedback information is constructed with information required by the communication environment.
Abstract:
An OLED device adapted to improve its life span and reliability is disclosed. The OLED device includes: a first electrode disposed on a substrate; an organic light emission layer disposed on the first electrode; a second electrode disposed on the organic light emission layer; an auxiliary electrode disposed on the second electrode; and a getter electrode, disposed on the auxiliary electrode, to remove at least one of moisture and oxygen.
Abstract:
A multiple-input multiple-output (MIMO) wireless communication system. A transmitter that includes a plurality of transmit antennas selects one of a spatial multiplexing scheme and a spatial diversity scheme, processes a signal in the selected transmission scheme, and transmits the signal through the plurality of transmit antennas. A receiver that includes a plurality of receive antennas processes a signal in a reception scheme mapped to a transmission scheme of the transmitter. The transmission schemes include a transmission scheme for maximizing diversity gain and a transmission scheme for maximizing spectral efficiency. The MIMO communication system using an adaptive transmission mode switching technique performs switching between MIMO transmission modes using spatial selectivity of a channel, thereby obtaining maximum gain in a signal to noise ratio (SNR) and spectral efficiency according to channel state.
Abstract:
A method for transmitting and receiving data in a multiuser Multiple-Input Multiple-Output (MIMO) system including a base station connected to a plurality of user equipments. In the method, each of the user equipments separately calculates channel capacity information using a linear reception scheme and a nonlinear reception scheme, and feeds back the calculated channel capacity information to the base station. The base station separately calculates system capacities using at least two different antenna scheduling schemes based on the channel capacity information fed back from the user equipments, and allocates antennas to the user equipments using a selected antenna scheduling scheme having higher system capacity out of the two antenna scheduling schemes.
Abstract:
A method of transmitting/receiving feedback information representing channel quality in a MIMO-OFDM system, in which a receiver measures channel qualities of signals transmitted on a plurality of subbands through a plurality of transmitting antennas by a transmitter, selects a predetermined number of subbands having a highest transmission performance based on the measured channel qualities and preceding information, determines at least one subband group with a maximum rate from among the selected subbands and the preceding information associated with the at least one subband group, and transmits feedback information to the transmitter, the feedback information including channel quality information about the at least one subband group and the associated preceding information.
Abstract:
A multiple-input multiple-output (MIMO) communication system is provided for communication between a transmission apparatus having a plurality of transmission antennas and a reception apparatus having a plurality of reception antennas. The reception apparatus performs singular value decomposition (SVD) on channel information for a channel established to the transmission apparatus, and feeds back the SVD-decomposed channel information to the transmission apparatus. The transmission apparatus receives the SVD-decomposed channel information from the reception apparatus, performs QR decomposition on the received SVD-decomposed channel information, and sets multiple transmission antennas to be allocated to the channel, thereby performing beamforming.
Abstract:
Disclosed herein is a dye-sensitized solar cell provided with a separation membrane between a photoelectrode and a counter electrode, in which, because the separation membrane serves as a support, it is possible to prevent damage thereto, the shorting between the two electrodes, and the leaning phenomenon of an electrolyte, and in which, because the separation membrane serves as a support, unit cells having large areas can be fabricated, so that the effective area thereof is increased, thereby realizing a highly efficient cell.
Abstract:
Disclosed is a method and an apparatus for transmitting/receiving signals in an multiple input multiple output (MIMO) wireless communication system. The method and apparatus including beam forming of a reference signal while predetermined codes are mapped on a one-to-one basis to each of a plurality of beams available for the transmitter and thereafter transmitting the beam-formed reference signal to a receiver. Also, if information representing an optimum beam, which maximizes reception performance, is received from the receiver, beam forming of data signals is performed by means of a beam corresponding to the information on the optimum beam and the beam-formed data signals are transmitted to the receiver. Therefore, it is possible to apply a beam forming scheme having minimum operation complexity and maximizing reception performance.
Abstract:
A method and apparatus for transmitting/receiving feedback information in a multi-user multi-antenna system and a system supporting the same are provided, in which all possible combinations are created using column vectors included in a precoding codebook, column vectors are correlated in each of the combinations, column vectors comprising correlations exceeding a reference threshold are designated as similar vectors, at least two similar vector sets are formed with the similar vectors, and feedback information is generated based on the at least two similar vector sets and transmitted.