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: Disclosed is a data transmission/reception method and system for minimizing intercarrier interference (ICI) in a communication system using a multicarrier. The data transmission method by a transmitter includes grouping transmission signals in units of a predetermined number of transmission signals when the transmitter has received the transmission signals, multiplying each group of the transmission signals by a transmission coding matrix, and transmitting the transmission signals multiplied by the transmission coding matrix to a receiver.

Abstract: An optical disk player with improved opening and closing of a door, transport of a tray, and an improved pivoting structure of a chassis to pivot a turntable. The optical disk player includes: a body; a tray to move in and out of the body so as to transport an optical disk; a chassis installed to pivot inside the body; an optical pickup, which is installed to be able to move back and forth in the chassis, to record/reproduce information onto/from the optical disk that is rotatably placed on the turntable; a cover installed on a front of the body, the cover including: a door holder with an aperture through which the tray moves; a door to be able to slide along the door holder so as to open and close the aperture; and a cam driving device to activate the tray, to pivot the chassis, and to open and close the door by sliding.

Abstract: A disc recording/reproducing apparatus includes a main frame, a disc cartridge including a case with an opening on a bottom thereof to expose a disc-type recording medium and a window on a sidewall thereof, a shutter mounted in the case to expose and cover the opening, a rotary wheel operating in association with the shutter, and a latch unit formed at one side of the case to control rotation of the rotary wheel, a tray mounting the disc cartridge and moving with respect to the main frame, a shutter opening/closing unit connected to one side of the main frame, a rack member of a cantilever type contacting with the rotary wheel, and first and second connection ribs connected to a static part of the shutter opening/closing unit, and a cam guiding the rack member distanced in relation to or from the latch unit, during shutter opening/closing operations.

Abstract: An adaptive modulation scheme relating to an RA problem for maximizing the transmission rates of all users for maximum transmission rates in an OFDMA system including some users requiring to use services at fixed data rates. The scheme proposes introduction of an adaptive modulation using linear programming into an existing scheme for a system including a single kind of users, thereby enabling simultaneous execution of the adaptive modulation for all users in a system including two kinds of users. Further, the invention proposes another scheme of sequentially allocating subchannels to the users when the fixed transmission rate has a sufficiently small value, in order to reduce the complexity.

Abstract: Disclosed is an apparatus and a method for signal transmission and reception according to a pre-processing scheme in a MIMO mobile communication system. The method includes: inputting a symbol; and pre-processing the input symbol according to a pre-processing matrix corresponding to pre-processing matrix information and transmitting the pre-processed symbol through a corresponding transmission antenna, wherein the pre-processing matrix is determined in accordance with a number of transmission antennas and a rate used in the MIMO mobile communication system.

Abstract: An optical pickup actuator includes a blade, on which an objective lens is mounted, arranged so as to flexibly move by a plurality of suspension wires; magnets facing each other in a tangential direction, wherein the blade is between the magnets, first coils arranged in pairs on two sides of the blade in the tangential direction for focus driving and radial tilt driving, a pair of second coils arranged on two sides of the blade in the tangential direction for track driving, and a pair of third coils arranged on two sides of the blade in a tracking direction for tilt driving of the tangential direction. The optical pickup actuator is driven in four axes.

Abstract: A method of providing a mobile station with communication services through base station cooperation in a communication system. The method includes the steps of: receiving signals from two or more base stations; measuring a strength of each of the received signals; estimating an expected transfer rate of the mobile station; if the estimated expected transfer rate is below a predetermined reference value, selecting at least two bases stations in order of the strength of the received signal; feeding back information on the selected base stations and channel conditions thereof to a serving base station that is providing the mobile station with the communication services or to a base station that is to serve the mobile station; allocating power and resources to the mobile station by the selected base stations; and performing signal transmission/reception with the selected base stations by using the allocated power and resources.

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: A resource allocation method in a multiuser-multiple-input multiple-output/orthogonal frequency division multiple access (MIMO/OFDMA) system. In the multiuser-MIMO/OFDMA system feedback information is received from terminals. A channel gain and a transmission rate for each user are determined using the feedback information. An average channel gain for each user is computed according to the channel gain. The average number of bits for each user is determined according to the average channel gain. The number of subchannels for each user is computed according to the average number of bits for each user. At least one subchannel is allocated to each user according to the number of subchannels for each user. A modulation scheme for each of the at least one subchannel is determined. The resource allocation method adaptively allocates subchannels and bits according to channel environment, thereby considerably improving frequency use efficiency as well as a power gain.

Abstract: Disclosed is an adaptive receiving MIMO (multi input and multi output) system and method which decides a symbol detecting order so as to estimate the symbol having the minimum summation of weights of least square errors at the time of estimating the symbol for respective equalizers provided in parallel by the number of transmit antennas, and updates filter tap coefficients based on the RLS algorithm according to the detecting orders. Therefore, the filter tap coefficients are directly updated without tracking channels in the time-varying channel environment, and accordingly, detection performance very similar to those of the channel tracking and conventional V-BLAST scheme is provided with reduced complexity.

Abstract: An information processing system operating in response to a remote control signal transmitted from a remote controller, the information processing system including a remote signal receiver to receive the remote control signal; an interrupt generator to generate a system management interrupt signal when receives the remote control signal by the remote signal receiver; and a controller to process the remote control signal received by the remote signal receiver and to control the information processing system to operate in correspondence to the remote control signal when the interrupt generator generates the system management interrupt signal.

Abstract: An apparatus and method for implementing SDMA in a multi-user multi-antenna system are provided, in which SDMA users are selected from among total users according to channel state information of the total users, and the number of transmission streams to be allocated to each of the SDMA users is determined by a tree search method.

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: Provided are a system and a method for transmitting/receiving data in a communication system. The method includes calculating a processing matrix of a transmission unit for transmitting data, a processing matrix of a reception unit for receiving the data, a channel matrix formed by a plurality of transmission antennas and a plurality of reception antennas, and a parameter of the transmission data, when the data to be transmitted to the plurality of reception antennas via the plurality of transmission antennas is generated; determining a minimum value of a Minimum Mean Square Error (MMSE) according to the calculated matrixes and parameter; and transmitting/receiving the data using an MMSE multiplexing scheme based on the determined minimum MMSE value.

Abstract: A disk cartridge includes a case accommodating a disk, a cover installed at the case to be capable of being open and shut and having a hole formed thereon to be open to an outside of the cover, a shutter installed under the disk in the case to be capable of moving to open and shut an opening formed on the case, and a clamping member installed at the cover to seal the hole to clamp the disk. Thus, since the clamping member blocks the hole of the cover connected to the outside of the cover, possibility of intrusion of dust into the disk cartridge is reduced. Also, since there is no need to install the clamping member at the disk drive, the disk drive can be made simplified and slim.

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 disk drive including a tray on which a disk cartridge is mounted and is loaded into and unloaded from a main body; a guide formed on the tray; and an opening and closing member installed to be elastically connected to the guide. The opening and closing member has a second gear that rotates a rotating wheel by meshing with a first gear; and a first protrusion formed on one end of a second gear and to temporarily rotate the rotating wheel so that the first and second gears can mesh. The guide pushes the first protrusion during loading/unloading of the tray so that the first protrusion and the latch do not come in contact with each other.

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.