Abstract: The present disclosure relates to a lithium secondary battery in which an abnormal voltage drop phenomenon is improved. The lithium secondary battery comprises a negative electrode comprising a negative electrode active material, a positive electrode comprising a positive electrode active material represented by Formula 1, a separator disposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte solution comprises a lithium salt, a non-aqueous organic solvent, a compound represented by Formula 2 as a first additive, and lithium difluorophosphate as a second additive: LiaNixCOyM1zM2wO2??[Formula 1] wherein all the variables are described herein.

Abstract: The present disclosure provides a non-aqueous electrolyte including an additive for a non-aqueous electrolyte represented by Formula 1 below: wherein, R1 to R5 may each independently be any one selected from the group consisting of H, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkenyl group having 3 to 12 carbon atoms, and a nitrile group.

Abstract: A method and Mobile Subscriber Station (MSS) are provided for transmitting Channel Quality Information (CQI) in a wireless communication system. The method includes transmitting first information including a value related to CQI for at least one of bands; and transmitting second information including a differential CQI for the at least one of the bands, wherein each band comprises a plurality of adjacent subcarriers.

Abstract: A method and apparatus for transmitting and receiving a Hybrid Automatic Repeat reQuest (HARQ) burst in a communication system are provided. A transmitter obtains at least one Protocol Data Unit (PDU) according to a decoding order of a receiver which supports a HARQ mode. The receiver controls an order of at least one HARQ burst using burst information including a HARQ Channel IDentifier (ACID).

Abstract: A method and Mobile Subscriber Station (MSS) are provided for transmitting Channel Quality Information (CQI) in a wireless communication system. The method includes transmitting first information including a value related to CQI for at least one of bands; and transmitting second information including a differential CQI for the at least one of the bands, wherein each band comprises a plurality of adjacent subcarriers.

Abstract: A method and Mobile Subscriber Station (MSS) are provided for transmitting Channel Quality Information (CQI) in a wireless communication system using an Orthogonal Frequency Division Multiple Access (OFDMA) scheme. A Carrier to Interference and Noise Ratio (CINR) of at least two bands are measured; each of the at least two bands including a plurality of adjacent subcarriers for a band Adaptive Modulation and Coding (AMC) operation. A Report Response (REP-RSP) message including first information related to the measured CINR is sent. Second information related to a differential CINR of the at least two bands is sent via a Channel Quality Information Channel (CQICH).

Abstract: An apparatus and method for eliminating interference in a base station (BS) of a communication system. A first BS receives a first reception signal from a first mobile station located in a cell of the first base station. A second base station being adjacent to the first base station delivers decoding information of a second reception signal to the first base station, the second reception signal received from a second mobile station located in a cell of the second base station. The first BS determines whether an error exists on the second reception signal, based on the decoding information and re-generates an interference signal using the decoding information of the second reception signal when no error exists in the second reception signal, and performing interference elimination on the first reception signal using the re-generated interference signal.

Abstract: An apparatus and a method for interference cancellation in a broadband wireless communication system are provided. A receiving apparatus includes an estimator, a channel compensator, and a demodulator. The estimator estimates channels of a desired signal and at least one interference signal, estimates noise, calculates a mean interference power of each interference signal, and calculates a mean noise power. The channel compensator channel-compensates burst data. The demodulator calculates a noise variance value by adding the mean noise power to the at least one mean interference power and creates Log Likelihood Ratio (LLR) by demodulating the channel-compensated data.

Abstract: An apparatus and a method for determining a multi-antenna transmission mode at a base station in a multi-antenna system are provided. The method for determining the multi-antenna transmission mode includes when using a Multiple Input Multiple Output (MIMO) transmission mode as a multi-antenna transmission mode, determining a reference set point; updating a set point for transmit power control of a terminal according to an error occurrence of a signal received from the terminal; determining whether a channel to the terminal is a channel for applying the MIMO transmission mode by comparing the updated set point with the reference set point; and when the channel to the terminal is not a channel for applying the MIMO transmission mode, changing the multi-antenna transmission mode to a fixed transmission mode.

Abstract: A method and apparatus for transmitting and receiving a Hybrid Automatic Repeat reQuest (HARQ) burst in a communication system are provided. A transmitter obtains at least one Protocol Data Unit (PDU) according to a decoding order of a receiver which supports a HARQ mode. The receiver controls an order of at least one HARQ burst using burst information including a HARQ Channel IDentifier (ACID).

Abstract: An apparatus and method for estimating a Signal to Interference plus Noise Ratio (SINR) in a wireless communication system are provided. The method includes processing a received signal by Orthogonal Frequency Division Multiplexing (OFDM) demodulation to convert the received signal into frequency-domain data, selecting ranging data from the frequency-domain data, multiplying the selected ranging data by a ranging code to perform code demodulation, calculating at least one norm value and at least one coherent norm value by bundle for the code-demodulated data and estimating an SINR using the calculated at least one norm value and at least one coherent norm value.

Abstract: A Channel estimating apparatus and method for use in a broadband wireless communication system are provided. The receiving method includes determining a control unit for a channel estimation using burst allocation information of selected sectors; extracting pilot symbols from received data based on the control unit; and acquiring a channel estimate value for each transmission unit by performing a Joint Channel Estimation (JCE) with the extracted pilot symbols that are based on the control unit.

Abstract: A method and Mobile Subscriber Station (MSS) are provided for transmitting Channel Quality Information (CQI) in a wireless communication system using an Orthogonal Frequency Division Multiple Access (OFDMA) scheme. A Carrier to Interference and Noise Ratio (CINR) of at least two bands are measured; each of the at least two bands including a plurality of adjacent subcarriers for a band Adaptive Modulation and Coding (AMC) operation. A Report Response (REP-RSP) message including first information related to the measured CINR is sent. Second information related to a differential CINR of the at least two bands is sent via a Channel Quality Information Channel (CQICH).

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 selecting at least two users to be serviced in SDMA in an SDMA wireless communication system are provided. All users are ordered according to a predetermined rule and all possible user combinations each having at least two users are created from the ordered users. An investigation limit number is set using the capacity of a jth user combination. Or a total investigation number is reduced by comparing the interference-reflected SNR decrements of users with an investigation threshold. Therefore, the computation volume for selecting SDMA users is decreased.

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: The present invention relates to a transmitter and a transmission method in communication system using three Tx antennas in order to maximize STFBC coding gain. An input symbol sequence is transmitted through a plurality of Tx antennas in a predetermined method.

Abstract: An apparatus and a method for determining a multi-antenna transmission mode at a base station in a multi-antenna system are provided. The method for determining the multi-antenna transmission mode includes when using a Multiple Input Multiple Output (MIMO) transmission mode as a multi-antenna transmission mode, determining a reference set point; updating a set point for transmit power control of a terminal according to an error occurrence of a signal received from the terminal; determining whether a channel to the terminal is a channel for applying the MIMO transmission mode by comparing the updated set point with the reference set point; and when the channel to the terminal is not a channel for applying the MIMO transmission mode, changing the multi-antenna transmission mode to a fixed transmission mode.

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 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.