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:
An adaptive interference suppression receiver for a DS/CDMA system includes: input signal generators outputting a part of received signals of receiver antennas that has a coding block's transfer code; adaptive filter blocks filtering a complex signal output from the input signal generators with a tap weight updated based on a constraint MMSE criterion and estimating phase and amplitude components of a specific user channel using the filtering output signal to generate a channel-estimated signal; a signal restorer combining the channel-estimated signal and the filtering output signal and restoring an original signal; a signal selector for selecting known training data signal or the restored signal; and error generators comparing the channel-estimated signal and the filtering output signal and calculating an error between the two signals.
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 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 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:
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 frictional variable transmission for a vehicle comprising a rotating unit rotated by an engine of the vehicle; a power-varying unit that varies, in a state of contacting the rotating unit, a rotational force transmitted from the rotating unit 21 by moving in a predetermined direction; a hydraulic clutch mounted off-center from the rotating unit, and varying between states of frictional contact with or separation from the power-varying unit by hydraulic pressure generated according to a depressed state of a clutch pedal, thereby controlling the transmission of rotational force of the power-varying unit; and a power transmitter linked to the movement of the hydraulic clutch, and transmitting a rotational force corresponding to an input state of rotational force transmitted through the rotating unit and the power-varying unit.
Abstract:
A parking mechanism for an automatic transmission includes a manual control shaft rotationally supported by a transmission housing, the manual control shaft cooperating with a shift lever, a detent plate mounted on the manual control shaft, an annulus gear formed on a transfer gear of the transmission, and a sprag interposed between the detent plate and the annulus gear, the sprag pivoting a fulcrum shaft which is fixed to the transmission housing.
Abstract:
This invention relates to a computer system having a screen saver with a power shutdown function and the control method thereof, comprising a timer for measuring time, an input device for inputting, and a controller for automatically terminating an operating system program when there has been no input signal from an input device for a predetermined time while a screen saver is operating. The computer system having a screen saver with a power shutdown function terminates all programs and the operating system program, such as Microsoft Windows, and then shuts down the power to a computer if there has been no input for a predetermined time while the screen saver is operating under the operating system program.
Abstract:
Provided is an apparatus and method for transmitting and receiving broadcasting data and supplementary data. The method includes: generating broadcasting data and supplementary data for a plurality of predetermined 3D broadcasting services to be provided to users; multiplexing the generated broadcasting data for broadcasting channels respectively allocated to the plurality of predetermined 3D broadcasting services, and multiplexing the generated supplementary data for one commonly broadcasting channel commonly allocated to the plurality of predetermined 3D broadcasting services; encoding the multiplexed supplementary data corresponding to a conditional access system; and transmitting the encoded supplementary data to the one common broadcasting channel, and transmitting the multiplexed broadcasting data to the allocated broadcasting channels.