Abstract: An apparatus and method in which a base station transmitter transmits the common beam to all mobile stations in a base station via an antenna array having at least two antennas, and forms a traffic beam according to a position of each mobile station. The base station transmitter determines a weight vector of the traffic beam based on a position of each mobile station. The base station transmitter calculates a common beam weight vector for all angles in order to minimize a difference between a power of a signal received at the mobile station through the antenna array and a template function of the antenna arrayat all angels; calculates a traffic beam weight vector in order to minimize a reception power difference between a traffic beam to be transmitted to a position of the mobile station and the common beam, based on the calculated common beam weight vector; multiplies the calculated traffic beam weight vector by a signal to be output to the antenna array; and transmits the traffic beam to the mobile station.

Abstract: A method is provided for transmitting a packet data unit (PDU) by a transmitter in a wireless mobile communication system. The method includes determining at least one desired transmission PDU, determining a modulation scheme corresponding to the number of PDUs, and transmitting a first indicator value indicating the number of PDUs and the modulation scheme, transmitting the PDUs, receiving a second indicator value indicating a reception state of the PDUs, from a receiver that receives the PDUs, determining a new PDU or a retransmission PDU according to the second indicator value, and determining a modulation scheme corresponding to the number of the determined PDUs, and transmitting a third indicator value indicating the number of PDUs and the modulation scheme, and the corresponding PDUs.

Abstract: Provided is an apparatus and method for simultaneously receiving data signals of two adjacent frequency allocation (FA) in a cellular environment. When there is another base station using an adjacent FA to an FA of the base station, a subcarrier mapper maps control information to subcarriers of predetermined sections such that a mobile station simultaneously receives data signals of the adjacent FAs. An inverse fast Fourier transform (IFFT) processor IFFT-processes data mapped to the subcarriers. Because two different BSs transmit the same data through independent paths, the mobile station can obtain a macro diversity gain. Also, it is possible to balance the loads of the two BSs.

Abstract: A method and system for performing an inter-FA handover in a communication system are provided. An MS receives from a serving BS neighbor BS information including a BS ID of at least one neighbor BS and a reference signal index of a reference signal used in the at least one neighbor BS. When it is necessary to scan the reference signal from the at least one neighbor BS, the MS scans the reference signal corresponding to the reference signal index. If the scanned reference signal has a quality equal to or greater than a threshold, the MS determines the BS ID of the at least one neighbor BS using the reference signal index as a BS ID for a recommended neighbor BS available for the inter-FA handover.

Abstract: Improvement of interference canceling efficiency and communication system capacity due to the use of the optimal decision function in adaptation of the adaptive antenna array weight factors. An adaptive antenna array pattern forming algorithm is used. The weight vector is determined from the position of the decision function maximum. The proposed decision function is based on estimation of signal to interference plus noise ratio (SINR) at the adaptive antenna array output and is no singular even without noise and interference.

Abstract: Disclosed is a method for determining handover of a mobile station by a mobile station in a mobile communication system. The method includes measuring a downlink reference signal intensity of a serving base station; determining to perform scanning for measurement of reference signal intensities of the serving base station and neighbor base stations, when the measured downlink reference signal intensity of the serving base station is less than a reference value, negotiating with the serving base station for a scanning period and the number of scanning repetitions, measuring the reference signal intensities of the serving base station and the neighbor base stations, and resetting the reference value when a reference signal intensity of the serving base station is greater than or equal to reference signal intensities of neighbor base stations.

Abstract: Provided is a method for determining handover of a mobile station by a serving base station in a mobile communication system. The method includes receiving traffic quality information from the mobile station; determining whether the traffic quality information satisfies a preset setting condition; if the traffic quality information satisfies the setting condition, sending a request for pilot signal strength measurement for the serving base station and adjacent base stations to the mobile station; receiving pilot signal strengths of the base stations, reported by the mobile station; determining whether there is a corresponding base station whose pilot signal strength exceeds the pilot signal strength of the serving base station; and determining handover of the mobile station to the corresponding base station.

Abstract: Disclosed is a method of preventing a replay attack during a handoff in a communication system using a Mobile IPv6 protocol. A mobile node creates a CoA (Care of Address) by handoff and sends the CoA to a correspondent node, thereby creating a binding entry. Upon receipt of a binding update message including a HoA and a CoA from the mobile node or an attacker, the correspondent node searches a binding cache for a binding entry having the same HoA (Home Address) and CoA as included in the binding update message. If it is determined that the binding entry has the same respective HoA and CoA as contained in the binding update message, the correspondent node checks a Used field of the binding entry. If it is determined that the Used field of the binding entry is equal to a predetermined value, the correspondent node sends a reauthentication command message to the mobile node.

Abstract: Disclosed is a method for controlling transmission power to be allocated to sub-carrier signals in a cellular communication system capable of dividing a frequency band into a plurality of sub-carrier bands and multiplexing the sub-carrier signals of the sub-carrier bands based on multiple frequency reuse factors.

Abstract: A method for transmitting a frame comprised of a plurality of slots over a dedicated control channel in a duration where there is no transmission message from a mobile station to a base station. Each slot in the frame is comprised of a first slot duration and a second slot duration. The first slot duration is provided with a power control signal and the second slot duration is provided with no signal at a partial duration thereof.

Abstract: A system and method for transmitting control information and data to a mobile station in a communication system using adaptive antenna technology defined in a broadband wireless communication system. In a method for transmitting and receiving information data in the wireless communication system, a base station separates information data to be transmitted into control information and user data, applies different modulation and coding schemes to the control information and the user data, and transmits the information data to an associated mobile station. The mobile station identifies the modulation and coding schemes of the information data received from the base station and demodulates a total of the information data according to the modulation and coding schemes, or independently demodulates the control information and the data according to the modulation and coding schemes.

Abstract: A method for providing a single-frequency network (SFN) service between a base station (BS) and a mobile station (MS) in a wireless communication system. The BS sets a first segment indicator in a medium access control (MAC) message field before transmission, if a resource allocation scheme corresponds to general data transmission. The BS sets a second segment indicator in the MAC message before transmission, if the resource allocation scheme corresponds to single frequency-based data transmission. The MS receives the MAC message from the BS, and performs renumbering according to the first segment indicator or the second segment indicator included in the received MAC message.

Abstract: An apparatus and method for transmitting/receiving channel quality information (CQI) in a communication system having a frame including subchannels corresponding to the same frequency reuse factor or different frequency reuse factors. A base station (BS) allocates at least one of the subchannels in the frame to a subscriber station (SS), and sends a transmission request for a CQI for a subchannel desired to be received, to the SS. The SS measures channel quality for individual subchannels requested by the BS in response to the CQI request, and transmits the measured channel quality to the BS.

Abstract: The invention provides a method and apparatus for transmitting signalling information to a receiver using a plurality of transmission antennas in a time switching configuration. The apparatus includes a controller for generating a switch controlling signal in a non-overlapped time cycle for selecting one of the plurality of transmission antennas to output a transmission signal in a fixed, non-overlapped time interval. The invention further provides for a receiving device for detecting a pilot channel signal from an input forward link signal and generating estimated phase and time values for detecting a traffic channel signal at the selected estimated time position and correcting a phase error of the detected traffic channel signal based on the estimated phase value, for signal decoding.

Abstract: A communication method in a mobile communication system in which an access terminal transmits to an access network DRC information indicating a selected one of forward data rates requested by the access terminal is provided. The access network designates a DRC information length DRC Length indicating a number of slots where the DRC information is repeated and transmits the designated DRC information length to the access terminal. The access terminal gates transmission of DRC information to the access terminal at one time slot in every DRC information length received from the access network.

Abstract: There is provided an encoding apparatus and method in a CDMA communication system. To encode input information of a k-bit sequence and generate a codeword with length N>(2k?1), an encoder encodes the input information using an (r, k) simplex code and generates a sequence of code symbols of length r (r=2k?1), a repeater repeats the sequence of code symbols t times ( t = ? N r ? + 1 ) , and a puncturer performs puncturing A times (A=rt?N) on the t repeated code symbol sequences so that the resulting codes have length N. The punctured symbols are distributed uniformly across the repeated code symbol sequences or confined to the tth repeated code symbol sequence.

Abstract: An apparatus and method for receiving a ranging signal in an OFDMA mobile communication system are provided. The ranging signal receiving apparatus including, a ranging subchannel extractor for extracting subcarrier values with a ranging signal from a (FFT) signal; a plurality of multipliers for code-demodulating the sub-carrier values by multiplying them by a plurality of ranging codes; each of a plurality of correlators for calculating a plurality of differential correlations in a code-demodulated signal received from a corresponding multiplier; each of a plurality of inverse fast Fourier transform (IFFT) processors for IFFT-processing differential correlations received from a corresponding correlator by mapping the differential correlations to predetermined subcarriers and each of a plurality of maximum value detectors for detecting a maximum value in an IFFT signal received from a corresponding IFFT processor and calculating a timing offset using an IFFT output index having the maximum value.

Abstract: An apparatus and method for adjusting a data region to which data bursts are allocated in a broadband wireless communication system are provided. A cell load is calculated using information about data bursts to be transmitted and then compared with a predetermined threshold. A data region is adjusted based on the cell load such that a subchannel occupation rate is uniform over an entire data burst transmission time period, if the cell load is less than the threshold.

Abstract: An apparatus and method for cell acquisition and downlink synchronization acquisition in an OFDMA wireless communication system are provided. In an SS apparatus in a broadband wireless communication system, a preamble subcarrier acquirer extracts subcarrier values having a preamble code from an FFT signal. A multiplier code-demodulates the subcarrier values by multiplying the subcarrier values by a preamble code. A correlator calculates a plurality of differential correlations in the code-demodulated signal. An IFFT processor IFFT-processes the differential correlations by mapping the differential correlations to subcarriers. A maximum value detector detects a maximum value from the IFFT signal and calculates a timing offset using an IFFT output index having the maximum value.

Abstract: An apparatus and method for transmitting forward link data to a handoff mobile station in a CDMA communication system. A service sector for the handoff mobile station registers the other sectors in the active set of the handoff mobile station as idle sectors upon request of a data service from the handoff mobile station, and transmits data traffic to the handoff mobile station, while the sectors designated as idle sectors discontinue transmission of data traffic and transition to an idle state.