Patent application number | Description | Published |
20080212462 | Apparatus for Generating Down Link Signal, and Method and Apparatus for Cell Search in Cellular System - A method for generating a downlink signal and searching for a cell from the downlink signal in an OFDM-based cellular system is provided. Thus, a pilot pattern is formed in the downlink signal, and the pilot pattern is formed of a product of a cell-specific scrambling code and a cell group-specific code. The scrambling code is different for each cell and the same for each sub-frame, and the cell group-specific code is different for each cell and different for each sub-frame. | 09-04-2008 |
20100115363 | COOPERATIVE H-ARQ SUPPORTING METHOD - In the hybrid automatic repeat request (H-ARQ) supporting method for cooperative transmission, a receiver selects one H-ARQ repeat method from among the chase combining method and the incremental redundancy method according to the SNR when the data packet cooperatively transmitted by transmitters generates an error. Also, the method for the receiver to select a repeat transmitter includes a method for selecting a repeat transmitter in advance, a method for removing a transmitting node from a repeat transmitter group when the SNR of the transmitting node is low, and a method for estimating the SNR of each transmitter for each predetermined time frame and selecting the transmitter having the greatest SNR as the repeat transmitter. | 05-06-2010 |
20100150214 | COMMUNICATION SYSTEM USING MULTI-USER MULTIPLE INPUT MULTIPLE OUTPUT (MU-MIMO) COMMUNICATION SCHEME - Provided is a multi-user Multiple Input Multiple Output (MU-MIMO) communication scheme. | 06-17-2010 |
20100234054 | SYSTEM FOR CONTROLLING INTER CELL INTERFERENCE IN CELLULAR MOBILE SYSTEM - Provided is a technology that eliminates or decreases inter-cell interference through an inter-cell cooperation in a cellular mobile communication system. A terminal generates channel state information (CSI) with respect to a plurality of base station, and transmits the CSI to a serving cell. The serving cell shares the CSI with a cooperation cell, and determines a cooperation transmission mode that decreases interference from the cooperation cell. | 09-16-2010 |
20100285810 | METHOD FOR TRANSMITTING DEDICATED REFERENCE SIGNAL, AND METHOD FOR RECEIVING DEDICATED REFERENCE SIGNAL - Provided are a method of transmitting a dedicated reference signal (DRS), a method of receiving a DRS, and a feedback method of a terminal. The method of transmitting a DRS includes determining a DRS transmitting resource for at least one terminal which is a target of transmission, and transmitting the DRS using the determined transmission resource and notifying the terminal of information about layer used by the terminal. The method of receiving a DRS includes determining a DRS receiving resource, receiving information about layer used by a terminal from a serving cell base station, and receiving the DRS for the terminal using the determined reception resource and the information about layer. Accordingly, a terminal can find the position and sequence of its DRS. In particular, in the case of multi-user multiple input multiple output (MU-MIMO) or joint scheduling, it is possible to prevent or remove signal interference using the DRS of another terminal. | 11-11-2010 |
20100303032 | METHOD AND SYSTEM FOR OPERATING COOPERATIVE RECEIVING DIVERSITY SCHEME AND SELECTIVE COOPERATIVE RELAYING - A selective cooperative relaying method, the method including: determining, by a base station, whether a mobile station for which the base station provides a service is the mobile station necessary for direct transmission or is the mobile station necessary for cooperative relaying via a relay station; and selecting, by a base station, mobile stations using a simple relaying scheme, a cooperative transmission diversity scheme, or a cooperative receiving diversity scheme from mobile stations necessary for the cooperative relaying via the relay station. | 12-02-2010 |
20110014865 | COOPERATIVE RECEPTION DIVERSITY APPARATUS AND METHOD BASED ON SIGNAL POINT REARRANGEMENT OR SUPERPOSITION MODULATION IN RELAY SYSTEM - Disclosed is an apparatus and method for cooperative reception diversity based on signal point rearrangement or superposition modulation in a relay system, the method includes receiving a superposition-modulated symbol from a transmitting unit, demodulating the received symbol and decoding the demodulated symbol, modulating the received symbol using superposition modulation different from the superposition modulation used in the transmitting unit, and then relaying the modulated symbol to a reception unit, calculating an LLR of the symbol when a certain superposition-modulated symbol is received from a transmitting unit, calculating an LLR of a symbol modulated using superposition modulation different from the superposition modulation used in the transmitting unit when the symbol modulated using the different superposition modulation is received from a relay station, and summing and combining an LLR of each symbol received through the transmitting unit and relay station. | 01-20-2011 |
20110044313 | APPARATUS AND METHOD FOR TRANSMITTING DATA USING MULTIPLE ANTENNA FOR SINGLE CARRIER FREQUENCY DIVISION MULTIPLE ACCESS SYSTEM - Disclosed is a technique in which multiple antennas are applied to a mobile communication system using a single carrier frequency division multiple access method. | 02-24-2011 |
20110081902 | METHOD OF TRANSMITTING CONTROL INFORMATION USING PHYSICAL UPLINK SHARED CHANNEL REGION IN MIMO ANTENNA SYSTEM - Provided is a method of transmitting control information using a physical uplink shared channel (PUSCH) region in a system employing a multi-input multi-output (MIMO) antenna system in which transmission is performed through a plurality of layers. A method of transmitting a channel quality indicator (CQI)/precoding matrix indicator (PMI) using a PUSCH region in a system employing a MIMO antenna system in which transmission is performed through a plurality of layers includes encoding the CQI/PMI using one channel encoder, and transmitting the encoded CQI/PMI using some or all of the layers. Accordingly, it is possible to transmit uplink control information through a PUSCH region using a plurality of layers. | 04-07-2011 |
20110135024 | PRECODING MATRIX DESIGN METHOD FOR MULTIPLE BASE STATION USING MIMO TECHNIQUE - Provided is a precoding matrix design method for a cooperative communication of multiple base stations in a multiple input multiple output (MIMO) communication system. A method of designing a precoding matrix in a base station of the MIMO communication system may include: determining whether to use a cooperative communication; verifying a cooperative base station when the cooperative communication is determined to be used; selecting a precoding matrix to be applied by a home base station and the cooperative base station; and requesting the home base station and the cooperative base station for the cooperative communication using the selected precoding matrix. | 06-09-2011 |
20110151918 | COMMUNICATION SYSTEM INCLUDING BASE STATIONS AND TERMINAL FOR MULTI-CELL COOPERATIVE COMMUNICATION - Provided is a communication system for a multi-cell cooperative communication. A serving base station and at least one neighboring base station may communicate with at least one terminal through mutual cooperation. Each of the serving base station and the at least one neighboring base station may shift a phase of at least one element among elements included in a precoding matrix, using a phase shift matrix, and precode at least one data symbol. A terminal may feed back preferred phase shift matrix information to the serving base station, so that the serving base station and the at least one neighboring base station may adaptively determine a phase shift matrix. The terminal may calculate the phase shift matrix with small calculation amounts. The serving base station, the at least one neighboring base station, and the terminal may pre-store a plurality of candidate matrices with respect to the phase shift matrix. | 06-23-2011 |
20110176632 | METHOD OF TRANSMITTING UPLINK DM-RS MULTIPLEXED WITH DATA IN UPLINK MIMO TRANSMISSION - Provided is a multi-layer transmission method of multiplexing and transmitting data and a demodulation reference signal (DM-RS) sequence in an uplink digital Fourier transform-spread-orthogonal frequency division multiplexing (DFT-S-OFDM) transmission employing multiple-input multiple-output (MIMO). The method includes allocating one DM-RS sequence as a DM-RS sequence of a first transmission layer for uplink transmission; allocating a DM-RS sequence whose cyclic shift (CS) value having the same sequence as the DM-RS sequence of the first transmission layer is configured to differ from that of the DM-RS sequence as a DM-RS sequence of a second transmission layer; and multiplexing layer-specific data and the layer-specific DM-RS sequences according to each of the first and second transmission layers. Accordingly, an RS can be transmitted in more OFDM symbols of a slot or subframe without an increase in overhead. Consequently, it is possible to satisfy requirements of LTE-advanced that a high frequency spectrum and a high mobile velocity should be supported, and transmit and receive a DM-RS multiplexed with data while maintaining orthogonality. | 07-21-2011 |
20110195662 | TRANSMISSION DIVERSITY SCHEME OF MULTIPLE CELL COOPERATIVE COMMUNICATIONS - Provided is a method of applying a transmission diversity scheme in a multiple cell cooperative communication system in which a terminal may receive, from a plurality of base stations, identical data using an identical radio resource. In the method, base stations of a cooperative base station involved in a cooperative communication may apply the transmission diversity scheme using the same resource as time and frequency resources used to apply the transmission diversity scheme in a base station of a serving base station. | 08-11-2011 |
20110299482 | METHOD OF TRANSMITTING DOWNLINK CHANNEL RANK INFORMATION THROUGH PHYSICAL UPLINK SHARED CHANNEL - Provided is a method of transmitting channel rank information (RI) when the number of bits for transmitting the channel RI to be transmitted through a physical uplink shared channel (PUSCH) is three or more. The method includes mapping channel RI to be transmitted to a channel RI bit string of 3 bits or more, Reed-Muller coding and rate-matching the channel RI bit string using a basis sequence having a 32-bit code length, and generating modulation symbols by applying the bit sequence that has been Reed-Muller coded and rate-matched to a modulation mapper. Accordingly, the method of transmitting downlink channel RI can be employed when five or more antennas are used for downlink transmission or several carrier bands are used by carrier aggregation as specified in Third Generation Partnership Project (3GPP) long term evolution (LTE)-advanced following 3GPP LTE release 10. | 12-08-2011 |
20120046033 | COOPERATIVE COMMUNICATION METHOD IN CELLULAR WIRELESS COMMUNICATION SYSTEM AND TERMINAL FOR PERFORMING THE METHOD - Provided is a coordinated communication method in which a plurality of cells cooperate to perform multi-antenna transmission and reception in a cellular wireless communication system. A terminal wirelessly transmits channel state information (CSI) feedback to a serving cell and at least one coordinating cell. The serving cell and the coordinating cell perform multi-point coordinated communication using the CSI feedback. Even if the serving cell and the coordinating cell belong to different base stations, information exchange between the cells is minimized, so that a transmission delay and a traffic increment of a backhaul network can be prevented. | 02-23-2012 |
20120087393 | REFERENCE SYMBOL STRUCTURE FOR DFT SPREAD OFDM SYSTEM - Provided is a data transmission apparatus to transmit a reference orthogonal frequency division multiplexing (OFDM) symbol generated by frequency division multiplexing a reference symbol and a data symbol, and a data reception apparatus to estimate a channel using the reference OFDM symbol. Since the reference symbol and the data symbol are frequency division multiplexed, a Peak to Average Power Ratio (PAPR) may not increase greatly, and the transmission apparatus may transmit the reference OFDM symbol to the data reception apparatus more frequently. Accordingly, the data reception apparatus may estimate a channel accurately. | 04-12-2012 |
20120269285 | METHOD FOR GENERATING AND TRANSMITTING A REFERENCE SIGNAL FOR UPLINK DEMODULATION IN A CLUSTERED DFT-SPREAD OFDM TRANSMISSION SCHEME - Disclosed is a method for generating and transmitting a reference signal in a clustered DFT-spread OFDM transmission scheme. A method for generating and transmitting a DM-RS in a clustered DFT-spread-OFDM scheme comprises: a step of generating DM-RS sequences corresponding to the number of clusters allocated for an uplink transmission; and a step of mapping the generated DM-RS sequences to the relevant DM-RS symbol positions for each cluster. Accordingly, the method for generating and transmitting a reference signal according to the present invention, in which DM-RS sequences are allocated and transmitted on a cluster basis, uses a complete DM-RS sequence for each cluster, and therefore inter-cell interference can be weakened, and problems which might occur when applied to a multi-user MIMO (MU-MIMO) scheme can be solved. | 10-25-2012 |