Abstract: A method of transmitting a signal by using an Adaptive Modulation and Coding scheme in a Frequency Hopping-Orthogonal Frequency Division Multiplexing Access communication system capable of dividing total frequency bands into a plurality of sub-carrier bands and including a plurality of sub-channels, which are sets of predetermined sub-carrier bands, and a plurality of cells. The method includes the steps of allocating a predetermined number of sub-channels as AMC sub-channels per each cell matching with predetermined conditions in order to apply the AMC scheme to the AMC sub-channels, and allocating remaining sub-channels except for the AMC sub-channels as FH-OFDMA sub-channels in order to apply an FH-OFDMA scheme to the FH-OFDMA sub-channels.

Abstract: In a method for feeding back combination information of transmitted signals in a multiple-input multiple-output (MIMO) system using a multiple space-time block coding technique, mean square error values are computed in relation to the combination information pieces of the transmitted signals. An index of a combination having a minimum mean square error value from among the mean square error values is fed back.

Abstract: A display apparatus and method of displaying an image, and a video signal processor and method of converting an input video signal into a displayable format compatible with the display, including an reproducing apparatus reading out data stored on a medium, a playback part converting the data read by the optical disk drive into a video signal compatible with the video signal processor, an interface transmitting and receiving data to and from an external device, e.g., a computer, and a switching part selectively enabling the reproducing apparatus to communicate with either the drive playback part or the external device. With this configuration, embodiments of the present invention provide a display apparatus, computer system, and methods, using a display apparatus to play back a medium, e.g., a DVD having multimedia functionality, without having to boot the computer system.

Abstract: An optical pickup apparatus having laser light sources emit a first light beam having a relatively shorter wavelength for a DVD and a second light beam having a longer wavelength for a CD-R, an objective lens having a focal length of an information recording surface in the DVD, an optical path control unit controls the light beams so that the light beam emitted from one of the laser light sources is directed to the objective lens and the light output from the objective lens is directed to the optical detection unit, and a phase shift unit between the optical path control unit and the objective lens and which shifts a phase of the second light to reduce the size of a beam spot which is formed the information recording surface in the CD-R.

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: 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: A pilot designing method in an uplink OFDMA system is provided. In the uplink OFDMA system, communications are carried out in a frame divided into time-frequency lattices, and each time-frequency lattice includes a plurality of data symbol periods and a plurality of pilot symbol periods intermittently arranged with respect to the data symbol periods. The frame is divided into a plurality of blocks. The blocks are allocated to the terminals. A predetermined allocated pilot time-frequency lattice is shared between adjacent terminals.

Abstract: An actuator used with an optical pickup includes: a base on which a holder is fixed; a lens holder in which a plurality of installation holes are formed such that a plurality of objective lenses to record and/or reproduce optical discs having different recording densities are installed at different heights; a support member, which movably supports the lens holder, having one end coupled to the lens holder and the other end coupled to the holder; and a magnetic circuit which drives the lens holder in focusing and tracking directions. The plurality of installation holes include a first installation hole in which a first objective lens for at least one type of low density optical disc is installed, and a second installation hole in which a second objective lens for a higher density optical disc than the low density optical disc is installed.

Abstract: A computer system has a normal mode for performing its work in a normal and regular manner and a standby mode which progresses to a power saving mode after storing information about the state of the work in process in a memory.

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: 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: 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: An optical disc includes a substrate having micro-embossments, in which flat portions referred to as lands, and track guides, referred to as hills, and which protrude from the surfaces of the flat portions are formed. A reflective layer is formed on the substrate, a dielectric layer is formed on the reflective layer, a recording layer is formed on the dielectric layer, and a protective layer is formed on the recording layer. Thus, the lands and hills on the substrate of the optical disc enable disc fabrication to more easily facilitate manufacturing of the optical disc. Accordingly, tracks of the disc can be narrowed, to thereby enhance a recording density of the optical disc.

Abstract: A disk drive including a tray and an opener. The tray includes a disk cartridge mounted thereon and is loaded into and unloaded from a main body. The opener is installed in the main body and elastically contacts a guide formed on the tray. The opener includes a second gear and a first protrusion. The second gear rotates a rotating wheel when in contact with a first gear. The first protrusion formed on a first end of the second gear temporarily rotates the rotating wheel so that the first and second gears can mesh. The guide has a first cam that moves the opener such that the first protrusion does not interfere with the latch when the tray is loaded/unloaded.

Abstract: A communication method in an FH-OFDM communication system having a plurality of BSs is provided. A predetermined number of pilot pattern groups are generated, each pilot pattern group having a predetermined number of different pilot patterns for pilot transmission. The pilot patterns in each of the pilot pattern groups are mapped to different FH sequence sets. The pilot patterns and FH sequence sets are assigned to the BSs so that MSs within the service areas of the BSs can identify the BSs.

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: A code acquisition device securing reliable code acquisition and reducing a time required for a code acquisition procedure. In the device, a sampler samples an input signal, and a searcher continuously searches for a spreading code used for the sampled signal until the phase of the spreading code is acquired. A verifier verifies whether the phase of the spreading code used for the sampled signal is acquired, according to the search result of the searcher. The searcher initializes and restart the verifier whenever the phase of the spreading code is searched.

Abstract: An optical disc includes a substrate having micro-embossments, in which flat portions referred to as lands, and track guides, referred to as hills, and which protrude from the surfaces of the flat portions are formed. A reflective layer is formed on the substrate, a dielectric layer is formed on the reflective layer, a recording layer is formed on the dielectric layer, and a protective layer is formed on the recording layer. Thus, the lands and hills on the substrate of the optical disc enable disc fabrication to more easily facilitate manufacturing of the optical disc. Accordingly, tracks of the disc can be narrowed, to thereby enhance a recording density of the optical disc.

Abstract: An actuator for an optical pickup having a base on which a holder is fixed, a bobbin, a support member, and a magnetic circuit. Pluralities of installation holes are formed in the bobbin such that a plurality of objective lenses to record and/or reproduce optical discs having different recording densities are installed at different heights. The support member has one end coupled to the bobbin and the other end coupled to the holder movably supports the bobbin. The magnetic circuit drives the bobbin in focusing and tracking directions. The magnetic circuit is divided into a first magnetic circuit to drive the objective lenses in the focusing direction, and a second magnetic circuit to drive the objective lenses in the tracking direction, thereby reducing the weight of a moving portion.

Abstract: An actuator for an optical pickup having a base on which a holder is fixed, a bobbin, a support member, and a magnetic circuit. A plurality of installation holes are formed in the bobbin such that a plurality of objective lenses to record and/or reproduce optical discs having different recording densities are installed at different heights. The support member has one end coupled to the bobbin and the other end coupled to the holder movably supports the bobbin. The magnetic circuit drives the bobbin in focusing and tracking directions. The magnetic circuit is divided into a first magnetic circuit to drive the objective lenses in the focusing direction, and a second magnetic circuit to drive the objective lenses in the tracking direction, thereby reducing the weight of a moving portion.