Abstract: A method for transmitting pilots in a wireless communication system includes generating first two pilots for a first antenna. Second two pilots for a second antenna are generated by multiplying the first two pilots with two weight values respectively. The first two pilots are transmitted over two Orthogonal Frequency Division Multiplexing (OFDM) symbols via the first antenna. The second two pilots are transmitted over the two OFDM symbols via the second antenna, wherein each weight value is determined based on a value used to obtain a symbol index of a corresponding OFDM symbol of the two OFDM symbols within a slot. Symbol indexes for the two OFDM symbols are consecutive, and the two weight values are different with each other.

Abstract: The present invention relates to an apparatus and method for estimating a frequency offset in a wireless telecommunication system. The present invention does not estimate an initial frequency offset using a preamble which is the initial symbol of a frame upon estimation of the frequency offset in the wireless telecommunication system, but estimates a frequency offset using correlation of a cyclic prefix (CP) existing in each symbol, thereby eliminating a need to reproduce information about separate preamble signals and preamble signals, and easily estimating a frequency offset using only input signals.

Abstract: A frequency reusing method in a wireless communication system including a coverage region, which has first, second and third regions, and a radio access station (RAS) transmitting a traffic to a portable subscriber station (PSS) in the coverage region, comprises (a) transmitting the traffics by assigning an identical frequency band to the first, second and third regions during a first interval; (b) transmitting the traffics by assigning the identical frequency band to the first region during a second interval; (c) transmitting the traffics by assigning the identical frequency band to the second region during a third interval; and (d) transmitting the traffics by assigning the identical frequency band to the third region during a fourth interval.

Abstract: An apparatus and method for supporting MultiCast and BroadCast Service (MCBCS) proxy selection for MCBCS and macro diversity in a wireless communication system is provided. The apparatus and method selects a first MCBCS proxy among MCBCS proxies in the plurality of ASNs as a master MCBCS proxy, and selects other MCBCS proxies except for the first MCBCS proxy as slave MCBCS proxies, and the first MCBCS proxy transmits information for macro diversity to the slave MCBCS proxies, wherein the master MCBCS proxy first receives an MCBCS join message from a Mobile Station (MS) in one Multicast and Broadcast Service (MBS) zone.

Abstract: Provided are an apparatus and method for measuring a carrier-to-interference and noise ratio (CINR) using a pilot symbol in a digital communication system, and more particularly, to an apparatus and method for measuring a CINR by estimating a data signal, noise, and an interference signal from a pilot symbol in a digital communication system using orthogonal frequency division multiplexing (OFDM)/orthogonal frequency division multiplexing access (OFDMA). The apparatus includes: a pilot symbol acquisition unit for acquiring the pilot symbol from a baseband frequency signal; a signal estimation unit for estimating a pilot signal and a data signal from the pilot symbol; a power calculation unit for calculating a power value of the estimated data signal and calculating a power value of a noise signal from a difference between the pilot symbol and an estimated pilot signal; and a CINR calculation unit for calculating a CINR on the basis of the power values of the data and noise signals.

Abstract: Disclosed is an apparatus for switching MIMO modes, which can efficiently switch an MIMO mode of a mobile station. The apparatus for switching MIMO modes includes an MIMO mode determining unit, a staying time determining unit, and an MIMO mode switching unit. The MIMO mode determining unit determines a current MIMO mode of a mobile station. The staying time determining unit determines a first staying time in a first MIMO mode of the mobile station when the MIMO mode determining unit determines the current MIMO mode of the mobile station as the first MIMO mode for transmitting the same data through a plurality of antennas, and determines a second staying time in a second MIMO mode of the mobile station when the MIMO mode determining unit determines the current MIMO mode of the mobile station as the second MIMO mode for transmitting different data by antenna.

Abstract: Disclosed is a weight factor matrix determining method for beamforming in a base station in order for inter-cell interference to be removed. The weight factor matrix determining method for beamforming which includes: determining a first transmission power for a first terminal being a target terminal and a second transmission power for a plurality of second terminals other than the target terminal; calculating an Eigen vector with an Eigen value for a ratio of the first and second transmission powers; and determining a weight factor matrix in a serving base station, with the calculated Eigen vector.

Abstract: A method and apparatus of allocating downlink power in a radio access station system are disclosed. The method of allocating transmission power to a plurality of terminals in a radio access station system according to the present invention includes (A-1) calculating an allocation power for the respective terminals based on downlink quality information of the respective terminals; (A-2) calculating a minimum requirement power for the respective terminals based on the downlink quality information; and (A-3) allocating the transmission power by distributing part of excess power of a first terminal group having the allocation power higher than the minimum requirement power to the second terminal group having the allocation power lower than the minimum requirement power, and the part of excess power is a sum of insufficient power of the second terminal group. As a result, the loss of the quantity of service transmission of the radio access station is reduced and service areas can be expanded.

Abstract: The present invention relates to an apparatus and method for estimating and compensating for a time offset and a carrier frequency offset in a Multiple Input Multiple Output (MIMO) communication system that supports Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiplexing Access (OFDMA). According to the present invention, a phase difference of pilot signals of the same transmitting antenna, which are received through receiving antennas, is calculated. An arc tangent operation is then carried out on the phase difference of the pilot signals to calculate a time offset linear phase and/or a carrier frequency offset linear phase. Further, a time offset compensation value and/or a carrier frequency offset compensation value are found by employing the time offset linear phase and/or the carrier frequency offset linear phase.

Abstract: The present invention relates to an apparatus and method for allocating a MAP message region in a broadband wireless communication system having a multi-cell/-sector structure. The present invention allocates a common MAP message region for multiple cells/sectors and a data region, divides the common MAP message region into MAP message sections for each of the cells or each of the sectors, allocates MAP messages corresponding to each of the cells or each of the sectors to the divided MAP message sections and allocates data to be transmitted to each MS to the data region, and broadcasts multiple frames containing MAP message regions for each of the cells or for each of the sectors and the data region.

Abstract: Disclosed is a method and an apparatus for decoding transmission signal. The method includes the steps of: receiving transmission signal including repeated symbols; deinterleaving the received signal; mutually combining the repeated symbols in the deinterleaved signal; and decoding the combined symbols. According to the method, reception performance is improved as compared to a conventional decoding method, and system performance is improved by reducing the loss of frame information included in an FCH.

Abstract: Disclosed are a method and device for supporting Multicast Broadcast Service (MBS). The device for supporting MBS includes a ranging determiner, an MBS determiner, and a message generator. The ranging determiner determines an action state of a mobile station according to a ranging request of the mobile station. The MBS determiner determines whether the mobile station has an MBS flow. The message generator generates a ranging request message on the basis of the action state and MBS flow. When the mobile station has the MBS flow, the message generator adds an MBS indication bit, representing “the mobile station is an MBS mobile station”, into a ranging purpose indication TLV of the ranging request message.

Abstract: The present invention relates to a system and to a method for efficiently managing at least one or more femto base stations (BSs) existing in a femto zone containing a plurality of femto cells and for managing the femto zone in a wireless communication network.

Abstract: Provided are a method and device for estimating a channel in a wireless communication system, and more particularly, a method of estimating a channel of an uplink signal in an orthogonal frequency division multiplexing (OFDM)/orthogonal frequency division multiple access (OFDMA) communication system supporting the Institute of Electrical and Electronics Engineers (IEEE) 802.16d/e standards and a channel estimation device employing the method. The method includes the steps of: extracting pilot symbols included in the received signal and estimating linear phase values using the pilot symbols; interpolating the pilot symbols along a time axis and obtaining first channel responses; interpolating the pilot symbols along a frequency axis according to the first channel responses and obtaining second channel responses; and calculating channel estimation values using the second channel responses and the linear phase values.

Abstract: Disclosed are an apparatus and a method for estimating a channel in a base station when using a Partial Usage of Sub-Channels (PUSC) mode in an uplink channel of the communication system supporting Orthogonal Frequency Division Multiplexing/Orthogonal Frequency Division Multiple Access (OFDM/OFDMA). For this, the channel estimation apparatus used in the communication system supporting the OFDM/OFDMA comprises a phase estimation/compensation unit estimating and compensating phase change of a channel by using pilots included in signals input by sub-channel; and a channel estimation unit estimating the channel by averaging the pilots of the signals of which the phase is compensated.

Abstract: Disclosed is a method for determining precoding matrix based on an open-loop MIMO scheme, which can enhance a diversity gain at a static communication environment or a low-mobility communication environment. The method for determining precoding matrix applies a first precoding matrix to downstream data to transmit the downstream data through a plurality of antennas, the first precoding matrix being selected from a codebook which comprises a plurality of precoding matrixes, and changes the first precoding matrix to a second precoding matrix per predetermined period, and applying the second precoding matrix to the downstream data to transmit the downstream data through the antennas.

Abstract: Disclosed is an apparatus for reporting transmission power. The apparatus for reporting transmission power includes a transmission power normalization unit, a message generation unit, and a transmission unit. The transmission power normalization unit normalizes a first transmission power at a current Modulation and Coding Scheme (MCS) level into a second transmission power at a reference MCS level, the current MCS level being an MCS level of a burst which is intended to comprise a transmission power report of a terminal. The message generation unit generates a message comprising the transmission power report of the terminal with the second transmission power defined therein. The transmission unit transmits the generated message to a base station.

Abstract: Disclosed is a portable internet system, and more particularly, to a method of supporting fast ranging upon handover. The method comprises calculating an action time based on a time when a handover confirmation message is received from a serving Radio Access Station (RAS), in a target RAS; and transmitting a fast ranging information message to a mobile station on the basis of the action time.

Abstract: The present invention relates to a method and system for controlling an uplink (UL) in a wireless communication system, wherein packet scheduling is performed on the data packet of a mobile station to allocate multiple bursts, the parameters of the mobile station and the multiple bursts are verified, and the parameters are used to determine the MCS (Modulation and Coding Scheme) level and transmission power level for the multiple bursts.

Abstract: The present invention relates to a multicast and broadcast service (MCBCS) system and method. According to the present invention, the MCBCS system comprises: an MBS distribution DPF (Data Patch Function) for receiving MBS data from an MCBCS server/controller and distributing the data; an MBS synchronization controller for acquiring GRE (Generic Routing Encapsulation) for the MBS data from the MBS distribution DPF and then generating an MBS synchronization rule; an MBS synchronization executor for executing MBS synchronization on the MBS synchronization rule received from the MBS synchronization controller; and an MBS DPF for receiving MBS data from the MBS distribution DPF, packaging the MBS data into an MBS burst and then transmitting the data to an MS (Mobile station). As such, multicast and broadcast services can be provided efficiently.