Patent application number | Description | Published |
20080198808 | SYSTEM AND METHOD FOR PERFORMING HANDOVER IN WiMAX MOBILE COMMUNICATION SYSTEM - Disclosed is a system and a method for performing handover in a Worldwide interoperability for Microwave Access (WiMAX) mobile communication system supporting broadband wireless access. The system includes a plurality of Mobile Stations (MSs); at least one distributed antenna having the ability to perform simultaneous communications with the plurality of MSs; and a base station connected to the at least one distributed antenna through optical fibers for performing communications and handovers with the multiple MSs. | 08-21-2008 |
20080200211 | SYSTEM AND METHOD FOR FORMING CELL BY USING DISTRIBUTED ANTENNAS IN WIMAX MOBILE COMMUNICATION SYSTEM - A system and a method for forming a cell by using distributed antennas in a World interoperability for Microwave Access (WiMAX) mobile communication system supporting a broadband wireless access communication system. A virtual cell is formed with a specific Mobile Station (MS) as a central part of the virtual cell by using distributed antennas, which improves the transmission capacity and the performance of an overall network system without changing the structure of a backbone network and the interface of the overall network system. The system includes, multiple MSes; distributed antennas for perform simultaneous communications with at least one MS among the multiple MSes, and for forming one virtual cell by communicating with the multiple MSes; and a Base Station (BS), which is typically connected to the distributed antennas through optical fibers, for communicating with the MSes. | 08-21-2008 |
20080205538 | METHOD FOR SER APPROXIMATION FOR OSTBC IN DISTRIBUTED WIRE COMMUNICATION SYSTEMS - A method for Symbol Error Rate (SER) approximation of an SER-based transmission power allocation operation for an Orthogonal Space Time Block Code in a DWCS equipped with multiple transmission Distributed Antennas (DA) geographically dispersed at random. The method for SER approximation includes the steps of: setting multiple combinable antenna subsets from the multiple DAs; selecting a quasi-optimal antenna subset A | 08-28-2008 |
20080212703 | METHOD AND APPARATUS FOR SUBCHANNEL ASSIGNMENT FOR SUPPRESSING INTERANTENNA INTERFERENCE IN OFDMA SYSTEM - Disclosed is a method and an apparatus for subchannel assignment for suppressing inter-antenna interference in an Orthogonal Frequency Division Multiplexing Access (OFDMA) system based distributed wireless communication system equipped with antennas that are randomly distributed in a geographical manner and can simultaneously communicate with multiple Subscriber Stations (SSs). The method includes selecting and obtaining access to distributed antennas which satisfy the data transmission rate that an SS requires and with which the SS can communicate; re-queuing a distributed antenna having the maximum transmitted power within the same cell in high priority; and assigning subchannels to the relevant distributed antennas in an order from the relevant distributed antenna having the high priority. | 09-04-2008 |
20080248805 | Method and apparatus for subcell selection for assigning subcarrier in DAS OFDMA scheme - Disclosed is a method and an apparatus for assigning a subcarrier to a subcell serviced by a Distributed Antenna System (DAS) employing an Orthogonal Frequency Division Multiplexing Access (OFDMA) scheme in a broadband wireless access system. The method includes dividing an overall frequency band into multiple subcarrier bands, assigning the multiple subcarrier bands to respective Base Stations (BSs) without overlap among the BSs adjacent to one another in assigning the multiple subcarrier bands corresponding to the divided overall frequency band to the respective BSs and dividing the assigned subcarrier bands and selectively assigning the divided subcarrier bands to multiple Remote Stations (RSs) connected with the BSs through optical fibers. | 10-09-2008 |
20100002643 | APPARATUS AND METHOD FOR INTER-CELL INTERFERENCE CANCELLATION IN MIMO WIRELESS COMMUNICATION SYSTEM - A method for operating a Mobile Station (MS) in a Multiple Input Multiple Output (MIMO) wireless communication system is provided. The method includes measuring channel quality for a serving Base Station (BS), if the channel quality is less than a threshold, measuring interference power from one or more neighbor BSs, determining a Precoding Matrix Index (PMI) and a priority metric for each neighbor BS, and feeding back at least one of the PMI, a PMI type indicator, the priority metric, and the channel quality to the serving BS. | 01-07-2010 |
20100232539 | Method and apparatus for transmitting control information for interference mitigation in multiple antenna system - A multiple antenna system including a mobile station and a base station are operable to perform a method for transmitting control information for interference mitigation. A Mobile Station (MS) can transmit control information for interference mitigation. The MS determines a first Precoding Matrix Index (PMI) and a second PMI for interference from an adjacent Base Station (BS). Based on a correlation level from correlation values between one of the first PMI and second PMI and the remaining PMIs in the codebook, the MS determines a level of a subset of PMIs, and feeds back information indicating the correlation level. | 09-16-2010 |
20110019613 | DOWNLINK PMI COORDINATION BASED ON BASE STATION ANTENNA CONFIGURATION - A Mobile Station (MS) apparatus and a Base Station (BS) apparatus, and methods for their operation in a wireless communication system, are provided. The method for operating the MS includes receiving Precoding Matrix Index (PMI) subset information from a BS, determining downlink channel quality of the BS, determining a PMI for the BS based on the PMI subset information and the determined downlink channel quality of the BS, and transmitting the determined PMI to the BS. | 01-27-2011 |
20110032872 | Apparatus and method for overhead reduction of feedback in closed loop MIMO system - A method and apparatus reduce overhead of feedback in a closed loop Multiple Input Multiple Output (MIMO) system. A controller feeds back the long-term Precoder Matrix Index (PMI) to a serving base station under direction of the serving base station when the long term PMI feedback transmission is required, generates a new codebook using the long term PMI, and determines a short term PMI from the new codebook. A feedback transmitter feeds back the short-term PMI to the serving base station. | 02-10-2011 |
20110053633 | Method and apparatus for triggering multicell MIMO schemes in multiple antenna system - A method for triggering multicell MIMO schemes in a multiple antenna system includes transmitting, at a Mobile Station (MS), a first feedback information for single-cell closed-loop MIMO to a Base Station (BS); requesting, at the BS, Normalized Interference Power (NIP) feedback from the MS based on the first feedback information; feeding, at the MS, the NIP back to the BS; selecting, at the BS, a first NIP threshold and a second NIP threshold based on the NIP fed back from the MS; and requesting, at the MS, one of a first MIMO scheme and a second MIMO scheme by comparing the calculated first and second NIPs with the first NIP threshold and the second NIP threshold. | 03-03-2011 |
20110092232 | APPARATUS AND METHOD FOR ELIMINATING INTER CELL INTERFERENCE IN MULTIPLE INPUT MULTIPLE OUTPUT WIRELESS COMMUNICATION SYSTEM - Provided is a device and a method for eliminating inter-cell interference in Multiple Input Multiple Output (MIMO) wireless communication system. The method for operating a user equipment for eliminating the inter-cell interference includes determining one or more optimum bands among bands not requested to be restricted from a neighboring cell, determining at least one of band and Precoding Matrix Index (PMI) to be requested to be restricted to the neighboring cell among the determined one or more optimum bands, and feeding back at least one of the band and PMI to be requested to be restricted to the neighboring cell to a serving base station. | 04-21-2011 |
20110103271 | CALIBRATION APPARATUS AND METHOD FOR MULTICELL MULTIPLE INPUT MULTIPLE OUTPUT TRANSMISSION IN MULTIPLE ANTENNA SYSTEM - A calibration apparatus and a calibration method for multicell Multiple Input Multiple Output (MIMO) transmission in a multiple antenna system are provided. More particularly, an operating method of a Mobile Station (MS) for performing calibration for multicell MIMO transmission in a multiple antenna system includes negotiating a multi-Base Station (BS) joint processing with a BS, receiving a control message including information instructing multi-BS calibration for sounding based on the multi-BS joint processing, from the BS; when receiving the control message involving the multi-BS joint processing, generating a second sounding sequence by mapping estimated phases of downlink channels per subcarrier of BSs to a first sounding sequence allocated from the BS, and transmitting the second sounding sequence, including the phases of the downlink channels per subcarrier, over a sounding symbol interval with respect to each of the BSs involving the multi-BS joint processing. Hence, feedback overhead in the calibration of the multicell MIMO transmission can be reduced. | 05-05-2011 |
20120015664 | METHOD AND APPARATUS FOR MITIGATING INTERFERENCE IN FEMTO CELL IN WIRELESS COMMUNICATION SYSTEM - A method for mitigating interference by a femto Base Station (BS) in a wireless communication system including a macro BS is provided. The method includes receiving information about resources allocated for a channel measurement signal from the macro BS, measuring an UpLink (UL) power by detecting a channel measurement signal transmitted from at least one Mobile Station (MS) to the macro BS based on the received information, determining MSs whose UL powers are greater than or equal to a threshold, and transmitting identification information for the MSs to the macro BS. | 01-19-2012 |
20120034911 | APPARATUS AND METHOD FOR PERFORMANCE ENHANCEMENT IN OPEN LOOP MULTI CELL MIMO SYSTEM - An apparatus and a method for operating a Mobile Station (MS) in a wireless communication system are provided. The method includes receiving a threshold for a gap of an average Receive (Rx) power between a neighboring Base Station (BS) and a serving BS, transmitting to the serving BS, identification information of a BS having the average power greater than a first value, receiving information of a BS involving joint processing generated using information of the BS having the average power greater than the first value, feeding Precoding Matrix Index (PMI) information of the BS involving the joint processing, back to the serving BS, receiving information indicating a PMI operation mode of the MS, from the serving BS, and determining a PMI operation mode according to the information indicating the PMI operation mode of the MS. | 02-09-2012 |
20120182897 | METHOD AND APPARATUS FOR NETWORK ENTRY IN HETEROGENEOUS NETWORK - An apparatus and a method for manage network entry in a heterogeneous network (HetNet). In the method for network entry of a terminal in a HetNet, a base station access signal for network entry is transmitted to a serving base station. A response message is received from the serving base station. An uplink parameter is controlled based on an indication of the serving base station included in the response message. An access request message is generated and transmitted to the serving base station. A downlink response message including information regarding a selected serving base station is received from the serving base station. An access response message including information for network entry is received from the selected serving base station. A network entry procedure is performed with the selected serving base station. | 07-19-2012 |
20120183028 | APPARATUS AND METHOD FOR RANGING IN DISTRIBUTED ANTENNA SYSTEM - An apparatus and a method for ranging in a distributed antenna system are provided. A method for an operation of a Mobile Station (MS) in a distributed antenna system includes obtaining per-group ranging code configuration information indicating a ranging code allocation for each antenna port group, determining an antenna port group that the MS belongs to, and performing a ranging procedure by one of a plurality of ranging codes allocated to the antenna port group that the MS belongs to. | 07-19-2012 |
20120190378 | METHOD AND APPARATUS FOR INTERFERENCE MITIGATION IN HETEROGENEOUS NETWORK USING BEAMFORMING - A method and apparatus provide interference mitigation in a heterogeneous network using beamforming. In the method, a macro Mobile Station (MS) receives a broadcast message including a Precoding Matrix Index (PMI) set restricted in a macro cell, measures a Signal-to-Interference plus Noise Ratio (SINR) and a channel power from an adjacent femto Base Station (BS) and calculates a PMI, determines whether to request a dedicated frequency resource for a macro MS on the basis of the measured SINR, the channel power from the adjacent femto BS, and the calculated PMI, and requests the dedicated frequency resource for the macro MS from a macro BS. | 07-26-2012 |
20120231830 | METHOD AND APPARATUS FOR INITIAL RANGING IN WIRELESS COMMUNICATION SYSTEM INCLUDING HETEROGENEOUS NETWORK - An apparatus and method for initial ranging in a wireless communication system including a heterogeneous network. An operation of a terminal includes selecting a serving cell considering a biased value of a base station applying range expansion. The operation also includes receiving ranging code classification information and threshold information associated with the serving cell. The operation further includes, if a channel quality with the serving cell is less than the threshold, selecting one a plurality of poor-expected-ranging codes indicated by the ranging code classification information, and performing initial ranging using the selected poor-expected-ranging code. | 09-13-2012 |
20120327872 | APPARATUS AND METHOD FOR NETWORK ENTRY IN A WIRELESS COMMUNICATION SYSTEM - In one embodiment, a method for network entry in a wireless communication system includes acquiring ranging code configuration information, which represents the corresponding relationship among multiple beam vectors, multiple ranging sequences, and multiple ranging channels, determining an optimal downlink beam vector, and transmitting one of the ranging sequences corresponding to the optimal downlink beam vector to a Base Station (BS) through one of the ranging channels corresponding to the optimal downlink beam vector. | 12-27-2012 |
20130089046 | METHOD AND APPARATUS FOR DISTRIBUTED SCHEDULING FOR ENHANCING LINK PERFORMANCE IN WIRELESS COMMUNICATION SYSTEM - A method for distributed scheduling in a transmission node of a wireless communication system is provided. The method includes transmitting a power signal through a first tone in a Transmission (Tx) block including tones mapped with a plurality of link identifiers, receiving a power signal from a reception node through a second tone indicating that data transmission is possible in a first Reception (Rx) block including tones mapped with a plurality of link identifiers, and receiving a power signal from the reception node through a third tone including information about a link identifier that is permissible to the reception node, in a second Rx block including tones mapped with a plurality of link identifiers. | 04-11-2013 |
20130107831 | APPARATUS AND METHOD FOR TRANSMITTING AND RECEIVING SIGNAL IN A NEAR FIELD COMMUNICATION SYSTEM | 05-02-2013 |
20130258972 | METHOD AND APPARATUS FOR GENERATING REFERENCE SIGNAL IN ANALOG/DIGITAL MIXED BF SYSTEM - A millimeter radio wave communication system. In a method for operating a base station (BS) in an analog/digital mixed BF system, an analog BF direction is determined. A digital BF precoder is determined for the determined analog BF direction. Digital BF precoding is performed using the digital BF precoder with respect to the determined analog BF direction. A DownLink Reference Signal (DL RS) is transmitted in the analog BF direction on which the digital BF precoding has been performed. | 10-03-2013 |
20140120937 | APPARATUS AND METHOD FOR MITIGATING INTER-CELL INTERFERENCE IN MULTIPLE ANTENNA SYSTEM - A method for operating a Base Station (BS) in a wireless communication system is provided. The method comprises of receiving at least one request set for at least one neighboring cell, from at least one Mobile Station (MS), updating the at least one request set based at least in part on a serving band of each MS, and transmitting the updated at least one request set to the at least one neighboring cell, wherein the request set comprises a band and a Precoding Matrix Index (PMI) for making a use restriction or recommendation request to a neighboring cell. | 05-01-2014 |