Abstract:
A minimum value/maximum value extractor and method including: a multiplexer for outputting data and inverted data receiving from data lines depending on a maximum/minimum value selecting signal; a plurality of maximum value extracting parts for receiving the output of the multiplexer, a clock signal and a reset signal, the extracting parts outputting a first output which becomes the same signal state as that of the initially input data bits and maintains "0" regardless of subsequent data bits value once the input data bit becomes "0" until the reset signal is applied, and a second output which follows the first output value by delayed by two clock cycles; a maximum value/minimum value signal generator for outputting a value which is a NORed value of all inputs from the extracting parts as a minimum value or a value which is an inverted value of the NORed value of all inputs from the extracting parts as a maximum value; and a plurality of reset signal generators for generating the reset signal for resetting the first output of the extracting parts as an initial value if the two input signals are at the same state,wherein a data string in which the second output of each maximum value extracting part is "1" is the data string having the maximum/minimum values among a plurality of data bit strings and a value output through the maximum/minimum value signal generator becomes the maximum/minimum value.
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:
Disclosed herein is an echo cancellation and echo channel estimation system that can relay transmit signals without interference with echo signals by canceling the undesired echo signals received by a relay. The echo cancellation and echo channel estimation system is designed to relay signals between a transmitter and a receiver through a relay using multiple antennas. The echo cancellation and echo channel estimation system includes a receive antenna, a preprocessing vector generation module, an echo cancellation module, and a transmit array antenna. The receive antenna receives a transmit signal from the transmitter and an echo signal via an echo channel. The preprocessing vector generation module generates a preprocessing vector and applies the preprocessing vector, the transmit signal and the echo signal, received from the receive antenna, to the echo cancellation module. The echo cancellation module cancels only the echo signal by multiplying the preprocessing vector, the transmit signal, and the echo signal. The transmit array antenna receives a retransmit signal from the echo cancellation module and resends the retransmit signal to the receiver.
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:
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:
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:
Disclosed is a method for acquiring synchronization in a mobile communication system using an Orthogonal Frequency Division Multiplexing (OFDM) scheme. The method includes modeling a power delay profile in time-varying frequency selective fading channel conditions by a specific function; detecting a log probability distribution function of a timing offset and a frequency offset in consideration of a correlation between a received signal and the received multi-path signal in the time-varying frequency selective fading channel conditions having the power delay profile modeled as the specific function; and estimating a timing offset and a frequency offset which maximize the log probability distribution function of the timing offset and the frequency offset.