Patent application number | Description | Published |
20080207117 | APPARATUS AND METHOD FOR SELECTING A RELAY MODE IN A MULTIHOP RELAY BROADBAND WIRELESS COMMUNICATION SYSTEM - An apparatus and a method for selecting one of a plurality of relay modes in a wireless communication system are provided. The method includes checking a channel state between a Mobile Station (MS) and each of at least one Relay Station (RS), selecting the relay mode for supporting a relay service using the determined channel state between the MA and each of the at least one RS, and providing the relay service to the MS using the selected relay mode. Thus, system throughput and outage performance can be enhanced by using the appropriate relay mode based on the MS distribution or the channel condition. | 08-28-2008 |
20080227498 | Low-Complexity Joint Transmit/Receive Antenna Selection Method For Mimo Systems - Provided is a low-complexity transmit/receive antenna selection method for Multi-Input Multi-Output (MIMO) systems. The method includes the steps of generating a gain matrix of receive channel, calculating norm values of channel gains for each row (receive antennas) and column (transmit antennas) of the generated gain matrix of the receive channel, selecting an antenna with the maximum norm value among the calculated norm values of channel gains, and repeatedly performing the process of alternately selecting transmit and receive antennas having the maximum channel gain value among the channel gain values of the selected antenna until a required number of antennas is all selected. | 09-18-2008 |
20080267111 | Data Transmitting Method in Wireless Communication System - In a method for transmitting data from a first node to a second node through first and second relay units in a wireless communication system: a) a first symbol is transmitted from the first node to the second node and the first relay unit during a first time slot section; b) the first symbol, which is received from the first node, is transmitted from the first relay unit to the second node during a second time slot section; c) a second symbol is transmitted from the first node to the second node and the second relay unit during the second time slot section; and d) the second symbol, which is received from the first node, is transmitted from the second relay unit to the second node during a third time slot section. | 10-30-2008 |
20080305798 | HANDOVER METHOD IN A WIRELESS MOBILE COMMUNICATION SYSTEM AND A SYSTEM THEREFOR - A handover method of a mobile station in a wireless mobile communication system and a system therefore are provided. The mobile station transmits a handover indication message to a serving base station, receives a ranging response message that comprises authentication information required for the mobile station to authenticate a target base station, receives fast ranging resources and transmits a ranging response acknowledgement (ACK) message, which comprises authentication information required for the target base station to authenticate the mobile station, to the target base station after receiving the fast ranging resources. Accordingly, a handover break time is minimized. | 12-11-2008 |
20090129401 | METHOD AND APPARATUS FOR STAGGERED ZONE RESOURCE ALLOCATION IN ORTHOGONAL FREQUENCY DIVISION MULTIPLE ACCESS SYSTEM - A method for staggered zone resource allocation in an orthogonal frequency division multiple access (OFDMA) system having a cluster includes: dividing a frequency resource of the OFDMA system into a plurality of time zones along a time axis; determining at least two resource allocation start zones among the plurality of time zones in at least two cells of the cluster, respectively; arranging users in each of the at least two cell according to a path loss in a descending order; and sequentially allocating the frequency resource to the arranged users from the at least two resource allocation start zones in the at least two cells, respectively. | 05-21-2009 |
20090219909 | METHOD FOR SWITCHING AND MANAGING FREQUENCY ACCESS IN COGNITIVE RADIO SYSTEM, BASE STATION AND SUBSCRIBER STATION USING THE SAME - Provided are a channel switching method for effectively performing channel switching in a cognitive radio system while protecting an incumbent user, a method of managing a frequency channel, and a base station and customer premises equipment (CPE) using the methods. In the channel switching method performed by the base station, a currently unavailable first frequency channel is detected from among at least one uplink/downlink frequency channel which is set as a communication channel with the CPE; a channel switching request message requesting switching from the first frequency channel to a second frequency channel is transmitted to the CPE; and the first frequency channel is switched to the second frequency channel when a channel switching report message reporting that channel switching is to be performed in response to the channel switching request message is received from the CPE. | 09-03-2009 |
20100316165 | APPARATUS AND METHOD OF TRANSMITTING/RECEIVING SIGNALS USING SIGNALING POINT ROTATION AT MUTUAL COOPERATION TRANSMISSION - An apparatus for and method of transmitting and/or receiving a signal by using signaling point rotation in mutually cooperative relaying are provided. The apparatus for transmitting a signal includes: a rotated I-channel generation unit rotating a symbol containing data of a first user, by a predetermined angle, and then, obtaining the I-channel (in-phase) component of the rotated symbol; a rotated Q-channel generation unit receiving a symbol rotated by a predetermined angle, of a previous time slot from a node of a second user performing mutually cooperative relaying with the node of the first user, detecting the I-channel component, and obtaining the Q-channel (quadrature-phase) component of a symbol containing data of the second user from the detected I-channel component; and a combining unit combining the I-channel component of the first user generated in the rotated I-channel generation unit and the Q-channel component of the second user generated in the rotated Q-channel generation unit, thereby generating one symbol. | 12-16-2010 |
20110033010 | APPARATUS AND METHOD FOR SELECTION OF PRECODING MATRIX - The present invention relates to an apparatus and a method for selection of a precoding matrix. In the present invention, a precoding matrix to enable an effective signal-to-noise ratio (ESNR) to have a maximum value with respect to a signal vector that requires retransmission is selected in a codebook and fed back to a transmitter. Accordingly, since the effective signal-to-noise ratio has the maximum value after the signal vector is retransmitted, it is possible to minimize a reception error probability of retransmission. | 02-10-2011 |
20110110471 | METHOD OF BANDPASS SAMPLING USING SINGLE SIDEBAND CONVERTING - The present invention provides a method of bandpass sampling which particularly includes the single-sideband signal conversion procedure prior to the sampling process in the purpose of lowering the required sampling frequency. Conversion of the bandpass RF signal into a single-sideband spectrum signal which has the spectrum components only in either the positive or the negative frequency domain is accomplished by bandpass-filtering, or more effectively by using a Hilbert transformer. This invention includes a method of finding the minimum sampling frequency for simultaneous frequency down-conversion of multiple RF bandpass signals. It is expected from this invention that the components additionally required in the RF receiver due to the proposed bandpass sampling method is the bandpass filters or the Hilbert transformer for single-sideband conversion, but the benefits from this invention could be the reduced ADC speed performance and the subsequent digital processing load in the receiver system because of the reduced data rates. | 05-12-2011 |
20110142163 | APPARATUS AND METHOD FOR MAPPING SYMBOL - In a symbol mapping method, transmission data is encoded to output information bits and redundancy bits. The information bits and the redundancy bits are mapped to a symbol according to a first mapping scheme at a first transmission, and the information bits and the redundancy bits are mapped to a symbol according to a second mapping scheme at a second transmission. | 06-16-2011 |
20110150129 | DEVICE FOR GENERATING CODEBOOK, METHOD FOR GENERATING CODEBOOK, AND METHOD FOR TRANSMITTING DATA - A device for generating a transmission codebook in a communication system including a multi-input multi-output (MIMO) antenna according to an embodiment of the present invention includes: a frequency determiner that determines a frequency to allow the transmission codebook to have an optimal characteristic; a precoding matrix generator that generates a precoding matrix on the basis of the frequency; and a codebook generator that generates a retransmission codebook to be used for retransmission on the basis of the precoding matrix and generates the transmission codebook on the basis of the retransmission codebook. | 06-23-2011 |
20120020200 | APPARATUS AND METHOD FOR PRECODING USING CHANNEL ORTHOGONALIZATION IN MULTI-USER MULTI-ANTENNA SYSTEM - An apparatus and method for transmitting in a multi-user multi-antenna system are provided. The apparatus includes a precoder for orthogonalizing a channel by removing a channel element of a corresponding terminal with respect to multiple terminals, for determining an effective channel of each terminal by decomposing the orthogonalized channel using Singular Value Decomposition (SVD), for determining a precoding matrix using the effective channel, and for mapping data streams of the multiple terminals to a plurality of transmit antennas using the precoding matrix, and the plurality of the transmit antennas for transmitting the data streams of the multiple terminals. Hence, it is possible to obtain an iteration algorithm performance requiring considerable computation while avoiding complexity and reducing computation. | 01-26-2012 |
20120163268 | METHOD AND SYSTEM FOR PROVIDING MULTICAST AND BROADCAST SERVICE USING SCALABLE VIDEO CODING - A method and system for efficiently transmitting data, to which scalable image coding has been applied over a single frequency network is provided. The system includes a control server which re-packetizes data packets, received from a multimedia server, into a scalable bit stream by separately encoding the data packets into a base layer and one or more enhancement layers, and at least one base station which adaptively multicasts and broadcasts the scalable bit stream, received from the control server, to a plurality of terminals located in the area of a cell. The at least one base station multicasts and broadcasts the base layer across the area of the cell, and adaptively transmits the one or more enhancement layers depending on channel status or terminal performance of the plurality of terminals. | 06-28-2012 |
20120270593 | METHOD AND APPARATUS FOR POWER CONTROL AND LOAD BALANCING BASED ON LOAD ESTIMATION OF NEIGHBOR CELL IN WIRELESS COMMUNICATION SYSTEM - A Base Station (BS) operation method for reducing load terminals based on load estimation of a neighbor cell in a wireless communication system includes receiving information for estimating a load of a neighbor BS, determining whether to determine the power control and handover terminal set using the number of terminals serviced by the neighbor BS, the number of overload terminals among the terminals serviced by the neighbor BS, and the backoff counter value, and, when it is determined to determine a power control and handover terminal set, deciding the power control and handover terminal set to minimize load terminals, based on the first power variation and the second power variation. | 10-25-2012 |
20130010673 | RELAY METHOD FOR INCREASING FREQUENCY SELECTIVE CHARACTERISTIC OF WIRELESS CHANNEL AND RELAY DEVICE USING SAME - A relay method of a wireless communication system according to one embodiment of the present invention relates to a relay method of a wireless communication system in which at least one relay device communicates with a base station. The relay method comprises the steps of: each relay device setting information about a frequency band to be relayed, composing a control signal including the information about the set frequency band, and transmitting the control signal to at least one relay device; and receiving the control signal, extracting the information about the frequency band included in the control signal, amplifying the signal according to the information about the frequency band set in each relay device, and transmitting the amplified signal to at least one terminal. | 01-10-2013 |
20130329822 | APPARATUS AND METHOD FOR INTERFERENCE ALIGNMENT AND CANCELLATION IN WIRELESS COMMUNICATION SYSTEM - An apparatus and method for interference alignment and cancellation in a wireless communication system of a multi-user communication environment are provided. The apparatus includes a plurality of receivers, each receiver including a plurality of antennas for receiving signals from a plurality of transmitters. Each of the receivers detects signals of multiple users in a designed order and performs a specific interference alignment on the remaining signals. Also, each of the receivers transmits information about the detected user signal to other receivers to enable the other receivers to cancel the received user signal and perform a user signal detection and a specific interference alignment operation. Accordingly, it is possible to present various types of transmitter/receiver structures that can reduce the complexity while implementing the maximum capacity in an interference environment between a multi-user and single-user TX/RX pair. | 12-12-2013 |
20140297779 | METHOD AND APPARATUS FOR SENDING INFORMATION USING SHARING CACHE BETWEEN PORTABLE TERMINALS - A method for operating a receiving portable terminal in a mobile communication system includes receiving a first packet from a sending portable terminal, determining a fingerprint overlapping a fingerprint corresponding to at least one chunk of the first packet in a fingerprint set cache, determining a fingerprint set including the most redundant fingerprints, in the fingerprint set cache, determining at least one fingerprint to send, in the determined fingerprint set, sending the at least one determined fingerprint to the sending portable terminal, and receiving a second packet from the sending portable terminal. An apparatus includes a controller configured to determine at least one redundant fingerprint overlapping a fingerprint corresponding to at least one chunk of the first packet in a fingerprint set cache, determine a fingerprint set including the most redundant fingerprint in the fingerprint set cache, and determine at least one fingerprint to send in the determined fingerprint set. | 10-02-2014 |
20150017979 | METHOD AND APPARATUS FOR DISCOVERING NEIGHBOR DEVICE IN D2D COMMUNICATION NETWORK - A method of a Mobile Station (MS) for discovering neighbor MSs in a Device to Device (D2D) network includes broadcasting, by a discovery MS, a discovery request signal for discovering neighbor MSs, using a discovery request resource region repeated with a first period, if a neighbor MS discovery event is detected; and receiving, by the discovery MS, a discovery signal from at least one of other MSs in response to the discovery request signal, using a discovery resource region repeated with a second period. Other embodiments including a method for a central node discovering neighbor MSs and a discovery MS and a central node are also disclosed. | 01-15-2015 |
20150029931 | METHOD FOR TRANSMITTING DATA VIA SHARED RELAY STATION IN MOBILE COMMUNICATION SYSTEM - The present invention relates to a transmitting method for minimizing the delay time for data transmission via a wired backbone network using a shared relay station (SRS), wherein the steps of transmitting data and control information using the shared relay station comprises: a) sharing a relay station between at least two base stations (BS) and b) transmitting data via at least two base stations, terminals connected to the respective base stations, and a relay station. According to the present invention, the delay time for data transmission is minimized in comparison with conventional cellular networks, as data which was transmitted to a controller of a core network via a wired backbone network in the conventional cellular networks is transmitted to base stations or terminals via a wireless link by means of a shared relay station. | 01-29-2015 |