Abstract: Provided is a location measurement method of a mobile node using a predictive filter is provided for improving the location measurement accuracy of the mobile node. The location measurement method of a mobile node detects change of movement pattern of the mobile node, corrects weights of a location measurement period and a predictive filter depending on the change of movement pattern, and compensates a location of the mobile node using the corrected weights of the location measurement period and predictive filter.

Abstract: A location sensing system and method for a mobile communication system is provided for maintaining location sensing service with the support of mobile nodes when there is an insufficient number of anchor nodes for reference points. A location sensing method for a mobile communication system includes discovering, at a source mobile node, anchor nodes in a vicinity; discovering, when a number of discovered anchor nodes is less than a predetermined number of reference nodes required for location sensing, neighboring mobile nodes; selecting at least one of neighboring mobile nodes as a reference mobile node; and computing a location of the source mobile node in cooperation with the predetermined number of reference nodes including the discovered anchor nodes and the reference mobile node.

Abstract: Provided are a network-coding apparatus and method which can increase a data communication capacity in a communication environment to which an error-correction code (ECC) is applied. The network-coding apparatus includes a received signal processing unit receiving at least two signals, and decoding the at least two received signals; and a transmission signal processing unit receiving the at least two decoded signals from the received signal processing unit, merging the at least two decoded signals, and generating a merged transmission signal.

Abstract: Provided is a fine frequency synchronization method of a WiBro system, and particularly, a fine frequency synchronization method which measures a spread degree of a received signal of an adjacent subcarrier using orthogonality of PN sequences and thereby estimates a frequency offset, in a base station or a wireless repeater without using a GPS receiver. The fine frequency synchronization method includes: (a) performing despreading on received adjacent subcarrier sequences, using a PN sequence transmitted from a transmitting party; (b) obtaining ratios of correlative values obtained by the despreading; and (c) estimating a frequency offset on the basis of the ratio of correlative values. Accordingly, fine frequency offset estimation with relatively low complexity is possible without using a GPS receiver in a WiBro environment where interference signals of other base stations or repeaters exist.

Abstract: Provided is a location measurement method of a mobile node using a predictive filter is provided for improving the location measurement accuracy of the mobile node. The location measurement method of a mobile node detects change of movement pattern of the mobile node, corrects weights of a location measurement period and a predictive filter depending on the change of movement pattern, and compensates a location of the mobile node using the corrected weights of the location measurement period and predictive filter.

Abstract: A location sensing system and method for a mobile communication system is provided for maintaining location sensing service with the support of mobile nodes when there is an insufficient number of anchor nodes for reference points. A location sensing method for a mobile communication system includes discovering, at a source mobile node, anchor nodes in a vicinity; discovering, when a number of discovered anchor nodes is less than a predetermined number of reference nodes required for location sensing, neighboring mobile nodes; selecting at least one of neighboring mobile nodes as a reference mobile node; and computing a location of the source mobile node in cooperation with the predetermined number of reference nodes including the discovered anchor nodes and the reference mobile node.

Abstract: A method for transmitting a flooding ad hoc traffic indication message (FATIM) in a power save mode whose beacon interval is divided into an ad hoc traffic indication message (ATIM) window and data transmission window subsequent to the ATIM window, in a mobile ad hoc network (MANET) constituted by a plurality of nodes. When one of the plurality of nodes has data to be forwarded to different nodes, a FATIM frame indicating that a network broadcast message will be sent to its neighbor nodes is forwarded during the ATIM window. If a current ATIM window has not expired, at least one different node of the plurality of nodes receiving the FATIM frame forwards the received FATIM frame to its neighbor nodes.

Abstract: Provided is a fine frequency synchronization method of a WiBro system, and particularly, a fine frequency synchronization method which measures a spread degree of a received signal of an adjacent subcarrier using orthogonality of PN sequences and thereby estimates a frequency offset, in a base station or a wireless repeater without using a GPS receiver. The fine frequency synchronization method includes: (a) performing despreading on received adjacent subcarrier sequences, using a PN sequence transmitted from a transmitting party; (b) obtaining ratios of correlative values obtained by the despreading; and (c) estimating a frequency offset on the basis of the ratio of correlative values. Accordingly, fine frequency offset estimation with relatively low complexity is possible without using a GPS receiver in a WiBro environment where interference signals of other base stations or repeaters exist.

Abstract: Provided are a network-coding apparatus and method which can increase a data communication capacity in a communication environment to which an error-correction code (ECC) is applied. The network-coding apparatus includes a received signal processing unit receiving at least two signals, and decoding the at least two received signals; and a transmission signal processing unit receiving the at least two decoded signals from the received signal processing unit, merging the at least two decoded signals, and generating a merged transmission signal.

Abstract: An impulse signal acquisition method and apparatus are provided. The impulse signal acquisition apparatus includes: an impulse generator which varies a pulse width of an impulse signal used for transmitting data according to a predetermined control signal to generate the impulse signal; and a controller which applies a pulse width control signal used to vary the pulse width of the impulse signal to the impulse generator.

Abstract: A method for transmitting a flooding ad hoc traffic indication message (FATIM) in a power save mode whose beacon interval is divided into an ad hoc traffic indication message (ATIM) window and data transmission window subsequent to the ATIM window, in a mobile ad hoc network (MANET) constituted by a plurality of nodes. When one of the plurality of nodes has data to be forwarded to different nodes, a FATIM frame indicating that a network broadcast message will be sent to its neighbor nodes is forwarded during the ATIM window. If a current ATIM window has not expired, at least one different node of the plurality of nodes receiving the FATIM frame forwards the received FATIM frame to its neighbor nodes.

Abstract: A method for transmitting a hello packet from a plurality of nodes in a mobile ad hoc network (MANET). The nodes have a predetermined identical counter value. The nodes to simultaneously wake up during a predetermined beacon interval (BI) according to the predetermined counter value, and maintain an awake state in order to transmit/receive the hello packet.