Abstract: A transmitter for minimizing a PAPR in OFDM communication system. The transmitter includes: a precoder for coding input symbols so that a signal rotation is generated, and generating a complex vector including the coded symbols; an encoder for performing a frequency-space mapping for the symbols generated as the complex vector according to a predetermined scheme; a random mapper for randomly mapping the symbols for which the frequency-space mapping has been performed on a frequency plane through at least one transmit antenna; an Inverse Fast Fourier Transform (IFFT) unit for performing an IFFT for the symbols for which the frequency-space mapping has been performed; and a gradient algorithm unit for receiving IFFTed signals from the IFFT unit and reducing the PAPR.

Abstract: A method for transmitting and receiving messages in a home appliance networking system, wherein a first home appliance connected to a network appends a unique message identification number to a header of a message and transmits the resulting message to a second home appliance connected to the network. Messages transmitted and received among a plurality of home appliances can be distinguished from one another, resulting in a reduction in message transfer errors. Moreover, as needed, a group code corresponding to a specific group of home appliances may be appended to a transmitter message for control of the specific group so that the home appliances can be conveniently and efficiently controlled at one time.

Abstract: A method and apparatus are provided for calculating a log-likelihood ratio (LLR) for decoding in a receiver for a mobile communication system, wherein the method and apparatus determine selection bits for distinguishing four quadrants in a constellation representing signal points of transmission symbols, determine domain bits for distinguishing the signal points in each domain of the four quadrants according to a modulation order of the transmission symbols, repeat an operation of dividing a received signal into a real component and an imaginary component according to the number of determined domain bits, calculate and origin-shift absolute values of the real component and the imaginary component, and calculate LLRs for the selection bits. Further, the method and apparatus can subsequently calculate LLRs for corresponding domain bits each time the origin-shifted received signal is received.

Abstract: An apparatus and method for full-diversity, full-rate space-time block coding in a transmitter using two Tx antennas are provided. An input symbol sequence is STBC-encoded in a predetermined method and transmitted through the two Tx antennas.

Abstract: A space-time block coding apparatus and method in a transmitter with four transmit antennas in a system using a space-time block coding scheme, a pre-coder pre-codes an input symbol sequence by multiplying the input symbol sequence by ej?, ? being a phase rotation angle, in case of QPSK in range of 0???90, 23.5???24.5, or 65.5???66.5, in case of 16QAM in range of 0???90, 15.5???17.5 or 72.5???74.5, the pre-coded symbol sequence being reconstructed to have real and imaginary parts. A mapper generates symbol vectors by recombining the real and imaginary parts of the pre-coded symbol sequence in an interleaving scheme. A plurality of Alamouti coders encodes the symbol vectors in an Alamouti scheme and transmits the encoded symbol vectors through corresponding transmit antennas.

Abstract: A space-time-frequency block coding apparatus and method in a transmitter with three transmit (Tx) antennas are provided. An input symbol sequence is transmitted through three Tx antennas according to a permutation method using a selected transmission matrix in order to improve the performance of an STFBC.

Abstract: A space-time block coding apparatus and method for transmitting an input symbol sequence through a plurality of Tx antennas using a channel information from the receiver in order to improve the performance of a space-time block coding (STFBC). A pre-coder pre-codes an input symbol sequence by multiplying the input symbol sequence by ej?, ? being a phase rotation angle, the pre-coded symbol sequence being reconstructed to have real and imaginary parts. A grouping mapper forms a grouping pattern based on feedback channel information received from a receiver, and generates a grouping symbol sequence by multiplying the grouping pattern by the pre-coded symbol sequence. A mapper generates symbol vectors by recombining the real and imaginary parts of the grouping symbol sequence in an interleaving scheme. A plurality of Alamouti coders encodes the symbol vectors in an Alamouti scheme and transmits the encoded symbol vectors through corresponding transmit antennas.

Abstract: A space-time-frequency block coding apparatus and method in a transmitter with three transmit (Tx) antennas are provided. An input symbol sequence is transmitted through three Tx antennas according to a set method using feedback information received from a receiver or using a selected transmission matrix having regularities in order to improve the performance of an STFBC.

Abstract: A method and system for transmitting reference signals in a BWA communication system using a first transmit antenna, a second transmit antenna, and a plurality of sub-carriers. Each of the sub-carriers occupies a sub-frequency domain. In the method, reference signals for identifying a first transmit antenna are transmitted through a second predetermined number of sub-carriers in a first mini sub-channel transmitted through the first transmit antenna and occupied by a predetermined time domain and sub-frequency domains of a first predetermined number of sub-carriers, and reference signals for identifying a second transmit antenna are transmitted through the second predetermined number of the sub-carriers in a second mini sub-channel transmitted through the second transmit antenna and occupied by the time domain and the sub-frequency domains of the first predetermined number of sub-carriers.

Abstract: A method and apparatus for transmitting uplink acknowledge information (ACK) in a communication system using an orthogonal frequency division multiple access (OFDMA) scheme. The method includes receiving a data bit for the uplink ACK; outputting codewords corresponding to the data bit; performing quadrature phase shift keying (QPSK) modulation on symbols for ACK vector indexes corresponding to the codewords for the received data bit; performing inverse fast Fourier transform (IFFT) on a transmission signal having subcarrier clusters to which the modulated transmission symbols are allocated; and transmitting the IFFT-processed transmission signal.

Abstract: A system and method for allocating an adaptive modulation and coding (AMC) subchannel in a communication system for transmitting and receiving data through at least one antenna. A receiver examines at least one channel received from a transmitter, selects antenna transmission mode based on the examined at least one channel, selects an optimum frequency band based on the selected mode, and sends feedback information including selection information to the transmitter. The transmitter receives the feedback information from the receiver and allocates a frequency band to the receiver according to the received feedback information.

Abstract: Disclosed is a method for performing a soft handover in a Multiple Input Multiple Output (MIMO) Orthogonal Frequency Division Multiple Access (OFDMA) mobile communication system including a mobile station (MS), a serving base station (BS) and a plurality of neighbor BSs, each neighbor BS being different from the serving BS the serving BS providing a service to the MS. According to the method, the MS requests a soft handover to the serving BS when the serving BS detects that the MS must be handed over to one of the neighbor BSs, the serving BS notifies the neighbor BSs of the soft handover of the MS in response to the request for the soft handover, transmits signals to the MS using a predetermined coding scheme and a predetermined frequency region allocation scheme, and the neighbor BSs transmit signals to the MS using the predetermined coding scheme and the predetermined frequency region allocation scheme.

Abstract: An apparatus and method for transmitting uplink fast feedback information using a fast feedback channel in an orthogonal frequency division multiple access (OFDMA) communication system. A channel encoder generates uplink fast feedback information to be transmitted, and outputs codewords designed such that a minimum Hamming distance between the codewords is maximized, according to the uplink fast feedback information. A non-coherent modulator performs orthogonal modulation on transmission symbols corresponding to the codewords and allocates the orthogonal-modulated transmission symbols to subcarrier cluster. An inverse fast Fourier transform (IFFT) block performs IFFT on a transmission signal having the subcarrier cluster and transmits the IFFT-processed transmission signal.

Abstract: The present invention discloses a display device having a gate line and a data line crossing each other on a substrate to define a pixel region, a thin film transistor at each crossing of the gate line and data line, a pixel electrode about a circumference of the pixel region and having an opening at a central portion of the pixel region, the pixel electrode electrically connected to the thin film transistor, a piezoelectric lead lanthanum zirconate titanates (PLZT) layer in the opening of the pixel region, and a piezoelectric lead zirconate titanates (PZT) layer between the pixel electrode and the PLZT layer.

Abstract: Disclosed are an apparatus and a method for transmitting uplink control information in an OFDMA communication system. The method, in which the uplink control information is transmitted using an ACK channel in the OFDMA communication system, includes the steps of receiving data bits of the uplink control information, outputting transmit symbols of sub-carriers by performing orthogonal modulation with respect to symbols for codewords of the received data bits, and inverse fast fourier transforming and transmitting a transmit signal including bundles of sub-carriers allocated the modulated transmit symbols.

Abstract: A method for transmitting channel quality information (CQI) from a receiver station to a transmitter station in a wireless communication system which includes diversity mode consisted of spaced apart subcarriers and band AMC mode consisted of a number of bands comprised of a predetermined number of adjacent subcarriers. The method comprises the steps of transmitting an average CINR(Carrier to Interference and Noise Ratio) value for a full frequency band if the receiver station operates in the diversity mode; transmitting a differential CINR of a predetermined number of bins if the receiver station operates in the band AMC mode.

Abstract: An apparatus and method for maximizing the efficiency of a power amplifier by reducing the PAPR of a BS in a mobile communication system. A power controller between I and Q channel pulse shaping filters and a frequency converter calculates cancellation signals for signal pulses that increase the PAPR at each sampling period, pulse-shape-filters cancellation signals at the highest levels among the cancellation signals, and adds the filtered cancellation signals to the original signals. Thus, spectral regrowth outside a signal frequency band is suppressed. In the case of a system supporting multiple frequency allocations, the PAPR is controlled for each FA according to its service class. Therefore, minimum system performance is ensured and power use efficiency is increased.

Abstract: An apparatus and method for transmitting a processing result on a received data frame in an Orthogonal Frequency Division Multiple Access (OFDMA) mobile communication system. The method includes selecting an orthogonal codeword corresponding to the processing result among predetermined orthogonal codewords, and transmitting the selected orthogonal codeword through at least one subcarrier group assigned for transmitting the processing result. A length of the orthogonal codeword is determined according to a number of symbol units included in the subcarrier group, and the predetermined orthogonal codewords are orthogonal with each other.

Abstract: A method for allocating a frequency to a subscriber station (SS) in handover operation in an Orthogonal Frequency Division Multiple Access (OFDMA) system. In the method, the SS checks safety channel frequencies for a target base station (BS), generates a safety channel frequency request message for requesting allocation of the checked safety channel frequencies, and transmits the safety channel frequency request message. Upon receiving the safety channel frequency request message from the SS, a serving BS allocates frequencies for a requested channel, and transmits an allocation message with the frequency allocation information to the SS. The serving BS transmits a channel allocation request message to the target BS according to the frequency allocation information. Upon receiving the channel allocation request message, the target BS allocates the safety channel frequencies to the SS.

Abstract: The high-speed pattern storing and matching method includes dividing pattern data having a defined rule into parts having a defined length, tabulating and storing input position sequence information of the divided parts of the pattern data and information about the pattern data subsequent to the corresponding divided part of the pattern data, dividing input pattern data into parts having a defined length, independently searching the divided parts of the input pattern data, and determining whether the pattern data input according to each input position sequence are matched to the pattern data having the defined rules, thereby enabling high-speed pattern matching in real time and storing repeating words in one address of memories to enhance the memory efficiency.