Abstract:
An apparatus and a method for canceling interference using a space-frequency block coding in a multi-antenna system. The method includes confirming a code for coding to minimize a Pairwise Error Probability (PEP) of a transmit signal of which the PEP is maximized according to a time variation; and coding the transmit signal with the code and transmitting the coded signal via at least two antennas. Accordingly, the interference cancellation can be accomplished while lowering the complexity of the receiver without degrading the spectral efficiency.
Abstract:
In the ICI cancellation method for OFDM communication system, a receiver performs channel estimation using pilot subcarriers included in transmission signals transmitted from at least one transmitter. The transmitter generates the transmission signal in which pilot subcarriers and data subcarriers are regularly arranged, performs preceding on the transmission signal, modulates the pre-coded transmission signal into an OFDM symbol, and transmits the OFDM symbol. The receiver receives the OFDM symbol; demodulates the OFDM symbol, detects the pilot subcarriers from a demodulated signal, estimates channels using the pilot subcarriers, and restores the transmission signal using the estimated channels.
Abstract:
An apparatus and method for performing sequential scheduling in a multiple-input, multiple-output (MIMO) system is provided. The method includes the steps of: selecting a user which reports the greatest partial feedback information among a plurality of pieces of partial feedback information of all users in an initialization operation, and requesting channel feedback information to the selected user; and broadcasting the channel feedback information of the selected user to remaining unselected users upon receiving the channel feedback information from the selected user. Accordingly, a maximum capacity can be obtained by using only selective channel feedback information without having to feed back channel state information of all users.
Abstract:
A method for adaptively allocating resource can be simply implemented for reducing degradation of performance by effectively separating operations of sub-channel and time slot allocation and selection of modulation method and sequentially processing each of operations. A method for adaptively allocating resource in a communication system to sequentially process sub-carrier/time slot allocation and modulation method selection efficiently includes the step of a) computing average channel gains of sub-carriers/time slots for each user by using channel gains of sub-carriers/time slots for each user; b) computing average numbers of bits for each user by using required data rates and average channel gains of sub-carriers/time slots for each user; c) computing the number of sub-carriers/time slots allocated to each user and allocating the sub-carriers/time slots to each user; and d) selecting a modulation method with respect to each sub-carrier/time slot.
Abstract:
An apparatus and method for determining a beamforming vector in a codebook-based transmission beamforming system are provided. In a feedback method for a receiver in a codebook-based transmission beamforming system, forthcoming channel values for a forthcoming period are generated using M present and previous channel estimates. Effective channel gains for all transmission beamforming vectors included in a codebook are calculated using the forthcoming channel values. A codebook index corresponding to the maximum effective channel gains is fed back to a transmitter.
Abstract:
A unit for preventing a substrate from drying includes a transfer arm for transferring a substrate from a first bath containing a first cleaning solution to a second bath containing a second cleaning solution, a spraying part connected to the transfer arm, wherein the spraying part sprays a drying prevention solution from an upper portion of the substrate to a lower portion of the substrate, and a drainage container connected to the transfer arm, wherein the drainage container receives the drying prevention solution.
Abstract:
A method and apparatus for reducing power consumption in a display area of an electronic device such as a portable computer are provided. Such a method includes: (a) activating a mode of setting the display area to a white background screen using a first input command of a user; and (b) locating the white background screen over all windows, except for a current task window being displayed in part of the display area. Additionally, the apparatus for reducing power consumption in a display area includes an input unit receiving a first input command from a user; a mode activation unit for activating a mode of setting the display area to a white background screen according to a first input command from a user; and a location setting unit for locating the white background screen over all windows, except for a current task window being displayed in part of the display area. As a result, the lifetime of a battery of a portable computer is maximized by reducing power consumption in the portion of a display area that is not being used by a user.
Abstract:
A disk cartridge which includes a case having an upper wall, a lower wall, and a sidewall, which form an inner receiving space in which a disk is inserted, an opening formed in at least one of the upper wall and lower wall of the case to allow a recording/reproducing unit of a disk drive to access the disk therethrough, and an inlet hole formed at the sidewall of the case to allow the disk to be inserted into and withdrawn from the case therethrough.
Abstract:
Example embodiments of the present invention relate to an apparatus for manufacturing semiconductors and a method of inspecting a pellicle. Other example embodiments of the present invention relate to an exposure apparatus for manufacturing semiconductors. The apparatus may include a reticle, a pellicle and a reticle chuck. The reticle may be mounted on an upper surface of the reticle chuck and the pellicle may be attached to a lower surface of the reticle chuck so that the pellicle may be detached again. There may be an empty space formed between the pellicle and the reticle. The reticle chuck may include holes for supplying or exhausting a purging gas from the empty space. Because a simpler yet more efficient purging system may be installed to the reticle chuck, an effective measure may be provided against contaminations on the pattern surface of the reticle.
Abstract:
A cleaning unit and an electrophotographic image forming apparatus including the cleaning unit that prevents a cleaning blade from overturning is disclosed. The cleaning unit includes a cleaning blade that contacts an outer circumference of an object to be cleaned with a predetermined pressure, and thus removes material remaining on the outer circumference of the object while the object is rotating. A bracket is connected to one side of the cleaning blade and supports the cleaning blade. A support frame is connected to the other side of the cleaning blade (that is, a side opposite to the side where the bracket is connected), and is placed close to the object to be clean. The support frame prevents the cleaning blade from being bent in a rotation direction of the object.