Abstract:
Disclosed is a hybrid wireless communication system and a communication method in the system. The system supports time and frequency division duplexing modes and includes a base station having a cellular communication range based on a cellular mode and mobile stations within the cellular communication range. The base station divides each available frequency resource into frames for communication, and each frame switches between a real-time service mode and a non-real-time service mode at a switching time within the frame. Communication is performed with the mobile stations within the cellular communication range via at least one of an uplink and a downlink in the real-time service mode of each frame according to the frequency division duplexing mode. Communication is performed with the mobile stations via the uplink and the downlink in the non-real-time service mode of each frame according to an ad hoc mode based on the time division duplexing mode.
Abstract:
A method of fabricating an organic light emitting device includes forming a first electrode layer on a substrate, surface-treating the first electrode layer with CF4 plasma, forming a first common layer containing pentacene on the surface-treated first electrode layer, forming an organic light emitting layer on the first common layer, forming a second common layer on the organic light emitting layer, and forming a second electrode layer on the second common layer. The CF4 plasma treatment enhances the luminous efficiency of the organic light emitting device.
Abstract:
Apparatuses and methods are provided for transmitting and receiving uncompressed audio or video (AV) data by applying a different coding rate to each bit or each group of bits included in the uncompressed AV data according to significance of each bit or each group of bits. The apparatus for transmitting the uncompressed AV data includes a grouping unit which classifies bits of each pixel included in the uncompressed AV data into at least two groups of bits according to a significance of the bits; an encoding unit which performs error correction encoding on each of the at least two groups using a different coding rate; and a radio frequency (RF) processing unit which transmits the encoded, uncompressed AV data, which includes the pixels on which the error-correction encoding was performed, using a communication channel.
Abstract:
A digital broadcast transmitter/receiver, and a signal processing method thereof, includes a randomizer randomizing a dual transport stream which includes a normal data packet and a robust data packet and into which stuff bytes are inserted, a stuff-byte exchanger replacing the stuff bytes of the randomized data with known data, a first RS encoder performing RS-encoding of data output from the stuff-byte exchanger, a packet formatter performing an interleaving of the robust packet of the data output from the first RS encoder and reformatting the packet, an interleaver interleaving data output from the packet formatter, a trellis encoder performing a trellis encoding of interleaved data, a second RS encoder changing a parity by performing an RS encoding of the robust data of the trellis-encoded data, and a modulator modulating data output from the trellis encoder and RF up-converting the modulated data.
Abstract:
Apparatuses and methods are provided for transmitting and receiving uncompressed audio or video (AV) data by applying a different coding rate to each bit or each group of bits included in the uncompressed AV data according to significance of each bit or each group of bits. The apparatus for transmitting the uncompressed AV data includes a grouping unit which classifies bits of each pixel included in the uncompressed AV data into at least two groups of bits according to a significance of the bits; an encoding unit which performs error correction encoding on each of the at least two groups using a different coding rate; and a radio frequency (RF) processing unit which transmits the encoded, uncompressed AV data, which includes the pixels on which the error-correction encoding was performed, using a communication channel.
Abstract:
A relay method is disclosed in a cellular communication system including an access node for providing an access service using resources of a licensed band to a particular terminal among a plurality of terminals with a partial licensed band of the full frequency spectrum, and a relay station for relaying communication between the terminal and an access node. The relay method includes performing base station-led resource allocation on a licensed band for a terminal and a relay station located in a service area of the base station, and performing relay station-led resource allocation on the licensed band and an unlicensed band for a terminal located in a service area of the relay station.
Abstract:
Provided is an apparatus and method for receiving a differential space-time block code (STBC) without estimating a channel characteristic using an additional training sequence in a wireless communication system using a plurality of transmission/reception antennas. The apparatus for receiving a differential STBC includes a detector for detecting a symbol from a received differential STBC using a trellis diagram and a Viterbi algorithm, a deinterleaver for deinterleaving the detected symbol, and a decoder for decoding a signal deinterleaved by the deinterleaver.
Abstract:
In an orthogonal frequency division multiplexing (OFDM) mobile communication system, an apparatus and method allocates resources for data transmission and transmits/receives user data using the allocated resources. A full subcarrier band allocable for one cell is divided into a plurality of subcarrier regions. Subcarriers selected from subcarriers existing in one of the plurality of subcarrier regions are allocated for each of a plurality of sectors constituting the cell. The subcarriers are allocated such that subcarriers existing in different subcarrier regions are allocated for neighboring sectors in the cell.
Abstract:
Disclosed is a method for uplink scheduling in a communication system. The method for uplink scheduling in a communication system having a cellular structure hopping between sub-channels according to a predetermined rule whenever a signal is transmitted The communication system dividing a whole frequency band into a plurality of sub-carrier bands and including the sub-channels which are sets of the sub-carrier bands. The method includes determining a number of sub-channels to be allocated to a mobile station such that throughput of the mobile station is maximized based on a first predetermined condition in which a mobile station having a superior channel state is allocated with a greater number of sub-channels than a mobile station having an inferior channel state, and determining a modulation and coding scheme level according to a signal-to-interference and noise ratio (SINR) of a downlink channel reported by the mobile station based on a second predetermined condition capable of improving a channel state of the mobile station having an inferior channel state.
Abstract:
An orthogonal frequency division multiple access (OFDMA) communication system. The system has a plurality of cells, divides an entire frequency band into a plurality of subcarrier bands in each cell, and has subchannels that are a set of a preset number of subcarrier bands, respectively. Interference from neighbor cells of the plurality of cells is predicted. A time interval in which interference is absent and a time interval in which the interference is present are classified according to the interference predicted from the neighbor cells. Transmit power is equally distributed and allocated to subchannels capable of being allocated in the time interval in which the interference is absent. Transmit power is adjusted and allocated for the subchannels capable of being allocated such that inference to the neighbor cells does not occur in the time interval in which the interference is present.