Abstract: Disclosed is a multi-transceiver system adapted to estimate a frequency offset on basis of a test signal and a reference signal. Transceivers in the multi-transceiver system are adapted to transmit signals compensated with the frequency offsets.

Abstract: A Peak-to-Average Power Ratio (PAPR) reduction apparatus and method in an OFDM communication system are provided. In the PAPR reduction method, magnitude and phase components are extracted from transmission sample data. Peaks having magnitude components exceeding a threshold are detected by comparing the extracted magnitude components with the threshold. The highest of the peaks is detected and compared with the threshold. If the highest peak is greater than the threshold, the highest peak is updated.

Abstract: Provided are an orthogonal frequency division multiple assess (OFDMA) system and a method for controlling frequency offsets of subscribers in uplink communication. The OFDMA system solves a problem that the system performance is deteriorated in uplink communications because subscriber stations have different carrier frequency offsets. Each subscriber station compensates for a frequency offset thereof in response to a frequency offset control signal provided by a base station and then transmits an uplink frame to the base station. The base station compensates for an average frequency offset using the uplink frame, which has a small frequency offset shift because each subscriber station compensates for the frequency offset thereof previously, and thus the frequency offset of each subscriber station can be correctly compensated to prevent inter-carrier interference.

Abstract: There is provided a refrigerator. The refrigerator includes an icemaker for making and discharging ice, an ice bank for storing the ice discharged from the icemaker, an ice discharge duct for discharging the ice stored in the ice bank to the dispenser, and an approaching prevention unit that is disposed in the ice discharge duct to prevent a user from approaching the ice bank through the dispenser.

Abstract: The present invention relates to a mobile terminal. Specifically to a mobile terminal including a display including a touchscreen, a sensing unit for sensing an object in near-proximity to the touchscreen, a controller for altering an image appearing on the display according to at least one of a duration of the object near the touchscreen and a distance of the object away from the touchscreen.

Abstract: The present invention relates to a mobile terminal. Specifically to a mobile terminal including a display including a touchscreen, a sensing unit for sensing an object contacting the touchscreen and the object in near-proximity to the touchscreen, and a controller for controlling information appearing on the display according to the object contacting the touchscreen and movement of the object relative to the touchscreen.

Abstract: The present invention relates to a refrigerator, including: a refrigerating cycle having an evaporator (1a); a space for exchanging heat with the evaporator; a region for exchanging heat between the evaporator and the space; and a storage chamber and a door for defining the space, wherein at least one of the region, the storage chamber and the door has undergone at least one of a Kimchi lactic acid bacteria culture treatment and a Kimchi lactic acid bacteria culture exposure treatment.

Abstract: An Orthogonal Frequency Division Multiplexing (OFDM) signal receiving apparatus and method of estimating a common phase error (CPE) using data subcarriers (and pilot subcarriers) instead of only pilot subcarriers. In the OFDM signal receiver, a channel measurement unit estimates a channel from a fast-Fourier-transformed signal to generate information about good subcarrier indexes as channel state information (CSI). A Common Phase Error (CPE) estimation unit estimates good pilot subcarriers and good data subcarriers from an equalized signal output from an equalizer (EQ) based on the channel state information (CSI), calculates the first and second common phase errors from the estimated pilot and data subcarriers respectively, and combines the first and second common phase errors to generate a final common phase error.

Abstract: A circuit for detecting a guard interval in an orthogonal frequency division multiplication (OFDM) communication system, using two successive autocorrelation calculations for a received sample train. The circuit determines a guard interval by calculating the maximum correlation value first autocorrelation calculation step (delaying an OFDM signal by the length of valid data N, the useful data duration); and a second autocorrelation calculation step (delaying the OFDM signal by a guard interval detection period (N+G1), the sum of the valid data length (N) and the minimum guard interval (GI)). Performing two autocorrelation calculation steps provides improved detection of the guard interval, being free from noises and distortions and producing the maximum correlation value and position more distinctly.

Abstract: An apparatus for detecting a guard interval length (type) of a transmission symbol among the structure of an orthogonal frequency division multiplexing (OFDM) system receiver, to ensure proper operation of a symbol start detector and a fast Fourier transform (FFT) window position controller, is provided.

Abstract: Provided is a method of dividing a payload intra-frame for improving throughput of a carrier sensing multiple access/collision avoidance (CSMA/CA) wireless communication network. The payload intra-frame dividing method includes a data frame dividing step and a physical layer frame generating step in which a physical layer receives a plurality of data frames from an upper layer within a range of the maximum data frame length the physical layer can transmit and transmits the data frames as a single physical layer data frame. Furthermore, an acknowledge (ACK) frame is provided, which can minimize the deterioration of throughput even when a data frame, which has been divided into a plurality of data frames and transmitted as a single data frame, is required to be re-transmitted because an error is generated in the data frame.

Abstract: There is provided a multi-carrier transmission system which includes: an encoder for converting a data sequence into encoded symbols corresponding to respective sub-carriers; a first shifter for rearranging the encoded symbols to define a guard interval length; an inverse fast Fourier transform (IFFT) unit for inverse fast Fourier transforming the rearranged encoded symbols; a second shifter for processing the transformed symbols to effect a frequency shift to compensate for a frequency shift effected by the IFFT unit; and a guard interval inserter for interleaving symbol replicas with the processed symbols according to the guard interval length. The data transmission system of the present invention performs sub-carrier relocation function and guard interval insertion function using relatively simple elements in order to reduce the data processing time. As a result, the transmission efficiency of the entire communication system is enhanced.

Abstract: A power supply includes a transformer to transform an input voltage into an output driving voltage for one of a plurality of components of an image forming apparatus, and an output converter to detect the driving voltage being output from the transformer, to amplify the detected driving voltage according to a power control signal, and to output the amplified driving voltage to at least one remaining component in the plurality of components of the image forming apparatus. The power supply can not only control high voltage outputs individually, but also reduces the number of switching transformers being used, as it uses at least one shared switching transformer.

Abstract: A headset worn is provided to be on an ear in such a manner that a speaker is adhered to the ear. The headset includes a headset body; a hook unit for adhering and fixing the headset body to a user's ear part; a key positioned at a part of the headset body such that its key top protrudes; and a touch region having elasticity, and provided to maintain a distance from the key while facing the key, wherein, as the touch region is pressed, the key is pressed and enabled at the same time.

Abstract: Disclosed is a charging cradle for a headset device, which includes a housing with a surface providing a mounting depression, and a cover with a transparent surface pivotably connected to the housing so as to open and close the mounting depression. The headset device is mounted in the mounting depression so as to charge an internal battery pack provided in the headset device. The cradle protects the headset device under charging, enabling the user to observe the charging state without opening it. An earphone cover for a headset device includes a projected semi-circular fixing ring for preventing the earphone from being removed from the ear. The earphone cover is provided in various sizes to fit a user's ear size, and may be rotated to change the rotational position of the fixing ring so as to enable the user to put the headset device selectively on the right or left ear.