Patent application number | Description | Published |
20080205533 | METHOD OF TRANSMITTING USING PHASE SHIFT-BASED PRECODING AND APPARATUS FOR IMPLEMENTING THE SAME IN A WIRELESS COMMUNICATION SYSTEM - A method of transmitting data using a plurality of subcarriers in a multi-antenna wireless communication system is disclosed. More specifically, the method includes receiving feedback information from a mobile station (MS), performing channel encoding and modulation independently on user data to be transmitted by each antenna using the received feedback information, determining a phase shift-based precoding matrix for increasing a phase angle of the user data by a fixed amount, and performing precoding using the determined phase shift-based precoding matrix on the user data. | 08-28-2008 |
20080317157 | Method for Encoding Space-Time Codes in a Wireless Communication System Having Multiple Antennas - A method of transmitting space-time coded data in a wireless communication system having a plurality of antennas is disclosed. More specifically, the method includes allocating data symbols combined with complex weights to at least two transmit antennas during at least one specified time slot, and transmitting the data symbols combined with complex weights to a receiving end via the at least two transmit antennas during the at least one specified time slot. | 12-25-2008 |
20090052387 | METHOD FOR TRANSMITTING AND RECEIVING DATA WITH SUPERFRAME STRUCTURE - A method of transmitting and receiving data using a superframe structure is disclosed. A method for transmitting data through a superframe including a superframe header, includes generating the superframe which includes a data region including user data and includes a dedicated control region including data region allocation information indicating resource allocation for the data region, and transmitting the superframe. The dedicated control region is arranged at least one of locations except for a subframe of the superframe header. A user equipment which does not have to transmit and receive data decodes only data region allocation information using information of the data region indicated by a dedicated control region, thereby minimizing power loss, reducing a feedback delay, and reducing system overhead using a superframe structure. | 02-26-2009 |
20090147868 | METHOD AND APPARATUS FOR TRANSMITTING PILOT SYMBOLS IN WIRELESS COMMUNICATION SYSTEM - A method of transmitting pilot symbols is disclosed. In a communication system performing communications using a plurality of antennas and multiple carriers, the present invention includes the steps of generating a plurality of pilot symbol sequences based on a basic code sequence, data-processing a plurality of the pilot symbol sequences by allocating each of a plurality of the pilot symbol sequences to the multiple carriers, and transmitting each of a plurality of the data-processed pilot symbol sequences via a corresponding one of a plurality of the antennas. | 06-11-2009 |
20090220021 | METHOD FOR TRANSMITTING/RECEIVING SIGNAL HAVING SPREAD TRAINING SYMBOL IN MOBILE COMMUNICATION SYSTEM - A method for transmitting/receiving signals in a mobile communication system, a pilot configuration of a mobile communication system capable of transmitting much more data using a conventional pilot signal, a channel estimation method, and a receiving method are disclosed. A method for transmitting a signal equipped with a training symbol in a mobile communication system which includes a transmission end capable of transmitting an output signal equipped with a training symbol for channel estimation of a reception end, includes the steps of: a) adding training symbols having the same amplitude to data symbols transmitted via subcarriers, and calculating the output signal transmitted via the subcarriers; and b) transmitting the calculated output signal via the subcarriers. | 09-03-2009 |
20090316822 | METHOD OF TRANSMITTING SIGNALS FOR MULTIPLE ANTENNA SYSTEM - A signal transmission method for use in a multi-antenna system includes: receiving a complex signal using N antennas and M timeslots as a single unit, and generating a space-time code (STC) for performing interleaving and phase-shifting operations of the received complex signal; and applying the space-time code (STC) to the received complex signal, and transmitting the resultant signal. Therefore, the signal transmission method provides a space-time code (STC) provides a space-time code (STC) having higher performance and lower encoding complexity, and can effectively transmit the signal via the multi-antenna system. | 12-24-2009 |
20100014500 | METHOD FOR PERFORMING AN ADAPTIVE MODULATION AND CODING SCHEME IN MOBILE COMMUNICATION SYSTEM - An efficient link adaptive scheme according to a channel status in a broadband wireless communication system is disclosed. In applying an adaptive modulation and coding (AMC) scheme, modulation and coding selection (MCS) subsets are determined from all or part of MCS set in accordance with a service type or channel status, whereby feedback overhead is reduced and efficient link adaptation is performed in conjunction with a downlink power control scheme. | 01-21-2010 |
20100046464 | METHOD OF SUPPORTING HETEROGENEOUS MODE IN A WIRELESS COMMUNICATION SYSTEM - A data communication method is disclosed, which can simultaneously support heterogeneous systems in a wireless communication system based on multiple carrier multiple access. For a dual mode between heterogeneous systems, the data communication method includes transmitting control information for a first system mode and a second system mode to a mobile station through a channel resource zone used in the first system mode, and performing data transmission and reception between the system and the mobile station through channel resource zones allocated from the first system mode or the second system mode. | 02-25-2010 |
20100097949 | METHOD FOR TRANSMITTING AND RECEIVING FEEDBACK INFORMATION - A method for efficiently transmitting and receiving feedback information is disclosed. A cluster size as a unit for computing the feedback information and a reporting period of the feedback information are not uniformly determined by a base station. Information about a downlink channel status of each user equipment is reported, the cluster size and feedback period for computing and reporting the feedback information are determined using the information about the downlink channel status of each user equipment, and the feedback information is transmitted/received, thereby improving system capability. | 04-22-2010 |
20100142642 | METHOD FOR TRANSMITTING UPLINK CONTROL INFORMATION IN MULTIPLE-INPUT MULTIPLE-OUTPUT SYSTEM - A method for transmitting feedback information in a Multiple-Input Multiple-Output (MIMO) system is provided. The method constructs and transmits CQI (Channel Quality Information) channel including at least one CQI for uplink control information, wherein additional feedback information is included in at least one punctured bit among a plurality of bits allocated for the CQI channel. | 06-10-2010 |
20100177723 | METHOD AND APPARATUS FOR TRANSMITTING PILOT IN A WIRELESS COMMUNICATION SYSTEM - An apparatus for transmitting a pilot and method thereof are disclosed, by which a pilot can be efficiently transmitted in a wireless communication system. The present invention, in which the resource unit is transmitted by a base station in a wireless communication system, includes forming the resource unit including a plurality of pilot resource elements (REs) and a plurality of data resource elements, allocating a plurality of pilot pairs to have a prescribed subcarrier interval and a prescribed OFDM (orthogonal frequency division multiplexing) symbol interval within the resource unit, and transmitting the resource unit to a user equipment via multi-antenna, wherein each of a plurality of the pilot pairs includes individual pilots for two different streams or antennas. | 07-15-2010 |
20100183057 | METHOD FOR TRANSMITTING/RECEIVING MULTIPLE CODEWORD IN A MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION SYSTEM - A method for transmitting a multiple codeword (MCW) in a Multiple Input Multiple Output (MIMO) communication system is disclosed. A method for transmitting a multiple codeword (MCW) in a Multiple-Input Multiple-Output (MIMO) communication system includes performing a channel coding and modulation process for each codeword of the multiple codeword (MCW), multiplying the channel-coded-modulated result by a rotation matrix decided by either a spatial multiplexing rate or a layer (R), and performing a codeword permutation (CP) on the multiple codeword (MCW), performing a MIMO encoding on the multiple codeword (MCW), and transmitting the multiple codeword (MCW) via a multi-antenna. | 07-22-2010 |
20100195615 | TECHNIQUE FOR TRANSMITTING AND RECEIVING DOWNLINK REFERENCE SIGNALS - A technique for receiving and transmitting downlink reference signals is disclosed. When transmitting downlink data demodulation reference signals (DMRS) (or reference signals for downlink data demodulation) by using two or more layers, the DMRS of each layer may be multiplexed by using a code division multiplexing method and then transmitted. The DMRS for each of the two or more layers may be used for one user equipment or for two or more user equipments. And, downlink control signals for transmitting and receiving such DMRS may be configured to have the same format regardless of a single-user mode (or SU-MIMO mode) or a multi-user mode (or MU-MIMO mode), thereby being used. | 08-05-2010 |
20100202500 | DATA TRANSMITTING AND RECEIVING METHOD USING PHASE SHIFT BASED PRECODING AND TRANSCEIVER SUPPORTING THE SAME - A method for performing a precoding based on a generalized phase shift or a precoding based on an extended phase shift in a Multi-Input Multi-Output (MIMO) system employing several sub-carriers, and a transceiver for supporting the same are disclosed. A phase-shift-based precoding matrix is generalized by multiplying a diagonal matrix for a phase shift by a unitary matrix for maintaining orthogonality between sub-carriers. In this case, a diagonal matrix part may be extended by multiplying a precoding matrix for removing an interference between sub-carriers by a diagonal matrix for a phase shift. By generalization and extension of the phase-shift-based precoding, a transceiver is more simplified, and a communication efficiency increases. | 08-12-2010 |
20100208838 | UPLINK PRECODING METHOD IN 4-Tx SYSTEM - A method for a user equipment to precode and transmit an uplink signal efficiently in a 4-antenna system and a method for a base station to receive the transmitted signal efficiently are disclosed. Four antennas of a user equipment can be grouped by a 2-antenna unit. In consideration of this antenna group, it is able to perform precoding using antenna selection/DFT matrix of the antenna group unit. Moreover, a rank-3 codebook can be configured to include a precoding matrix of a type in consideration of power balance per antenna and a precoding matrix including one non-zero component only in one row for maintaining a good CM property. | 08-19-2010 |
20100220801 | UPLINK PRECODING METHOD IN 4-Tx SYSTEM - A method for a user equipment to precode and transmit an uplink signal efficiently in a 4-antenna system and a method for a base station to receive the transmitted signal efficiently are disclosed. Four antennas of a user equipment can be grouped by a 2-antenna unit. In consideration of this antenna group, it is able to perform precoding using antenna selection/DFT matrix of the antenna group unit. Moreover, a rank-3 codebook can be configured to include a precoding matrix of a type in consideration of power balance per antenna and a precoding matrix including one non-zero component only in one row for maintaining a good CM property. | 09-02-2010 |
20100239036 | METHOD AND APPARATUS FOR TRANSMITTING PRECODING MATRIX INDEX IN A WIRELESS COMMUNICATION SYSTEM USING CoMP SCHEME - A method and apparatus for transmitting a Precoding Matrix Index (PMI) in a Coordinated Multi-Point (COMP) communication system are disclosed. The method includes receiving signals in a same frequency band from Base Stations (BSs) included in a CoMP set, which operate in joint processing mode, selecting a first precoding matrix for each of the BSs using the received signals, generating a second precoding matrix by combining the first precoding matrices, and transmitting an index of the second precoding matrix to a serving BS among the BSs. | 09-23-2010 |
20100254292 | METHOD FOR CONTROLLING UPLINK POWER CONTROL CONSIDERING MULTIPLEXING RATE/RATIO - A method for maintaining system interference at a low level when two or more users use one resource region in a wireless mobile communication system is provided. To control an uplink transmission power in a broadband wireless mobile communication system in multi-cell environments, information regarding the number of users who share an uplink time-frequency resource region is received from a base station, a power adjustment value is calculated based on the received number of users, and the uplink transmission power is determined by reflecting the calculated power adjustment value in a reference transmission power. Here, when only one mobile station uses the uplink time-frequency resource region, the reference transmission power is equal to a transmission power of the mobile station. | 10-07-2010 |
20100254335 | METHOD OF TRANSMITTING CHANNEL STATE INFORMATION IN WIRELESS COMMUNICATION SYSTEM - A method of transmitting channel state information from a user equipment in a wireless communication system is disclosed. In order to report the channel state information, the user equipment is able to additionally transmit noise plus interference variance information as well as spatial channel matrix or spatial channel covariance matrix. The spatial channel matrix or spatial channel covariance matrix and the noise plus interference variance information can include information on a prescribed number of subbands in best channel states and can include information on a wideband including a plurality of subbands. Moreover, the user equipment is able to transmit normalized spatial channel matrix or spatial channel covariance matrix and normalized noise plus interference variance information for accurate and efficient transmission of the channel state information. | 10-07-2010 |
20100260243 | MIMO CODEBOOK GENERATION - Particular codebook entries used for a MIMO system of a lower dimension (i.e., having a relatively low number of antennas) can be used to generate a codebook for a MIMO system of a higher dimension (i.e., having a relatively high number of antennas). The entries in rank 1 of the codebook related to the MIMO system having four transmit antennas are used to newly construct entries for rank 1 through rank 8 of two base matrices for a MIMO base codebook related to eight transmit antennas. | 10-14-2010 |
20100265901 | METHOD FOR TRANSMITTING CHANNEL STATE INFORMATION IN A WIRELESS COMMUNICATION SYSTEM - A method for transmitting channel state information from an user equipment in a wireless communication system is disclosed. The user equipment transmits a spatial channel matrix or a spatial channel covariance matrix irrespective of a feedback type. The user equipment is able to additionally transmit noise plus interference variance information of a whole bandwidth used for the channel state information. In this case, the user equipment is able to transmit normalized spatial channel matrix or spatial channel covariance matrix and normalized noise plus interference variance information for accurate and efficient transmission of the channel state information. The user equipment receives an allocation of an uplink resource from a base station and is then able to map the spatial channel matrix or the spatial channel covariance matrix to the allocated resource according to a specific pattern. | 10-21-2010 |
20100303174 | APPARATUS FOR PROCESSING RECEIVED SIGNAL, METHOD THEREOF, AND METHOD FOR SELECTING MAPPING RULE - An apparatus for processing a received signal, method thereof, and mapping rule selecting method are disclosed, by which radio communications can be smoothly carried out in a receiving terminal ( | 12-02-2010 |
20100311349 | Method for Estimating Channel State in a Wireless Communication System Using Fractional Frequency Reuse and Mobile Station Using the Same - A method for estimating channel state in a wireless communication system and a mobile station using the same are disclosed. The method includes acquiring cell Identifiers (IDs) of a serving cell and one or more neighbor cells, acquiring information about preset power level patterns for one or more frequency partitions to which FFR is applied according to the cell IDs, and estimating a channel state of the serving cell based on the power level pattern information. | 12-09-2010 |
20100316093 | METHOD FOR DETECTING SIGNALS BASED ON DESPREADING AND METHOD FOR TRANSMITTING SIGNALS FOR THE SAME - A method for detecting signals based on despreading and a signal transmitting method for the same are disclosed. Signals are spread according to the size of at least one spreading band, which is determined in consideration of a correlation degree of a frequency band in a communication system. A reception side which receives the signals detects the signals after despreading with respect to signals which are spread in a frequency band having a correlation degree equal to or greater than a predetermined level as a spreading band, among the reception signals. Thus, the dimension of the detected signals can be decreased. | 12-16-2010 |
20110034192 | METHOD FOR AVOIDING INTER-CELL INTERFERENCE IN A MULTI-CELL ENVIRONMENT - A method for avoiding an inter-cell interference (ICI) in a multi-cell environment is disclosed. The method includes restricting the use of a PMI in an interfering cell so as to improve a reception performance of a mobile station located at an interfered cell edge. The mobile station measures a restricted-PMI of the interfering cell, which is prohibited from use in the interfering cell, and transmits the measured restricted PMI to the interfering cell. The use of the restricted PMI is prohibited from use in a mobile station in the interfering cell. | 02-10-2011 |
20110058512 | METHOD OF TRANSMITTING MULTICAST AND BROADCAST SERVICE DATA - A resource allocation method for a Multicast and Broadcast Service (MBS) and a method for transmitting MBS data in a wireless access system are disclosed. The MBS transmission method for a multicast broadcast single frequency network (MBSFN) zone includes, constructing a resource zone by sequentially allocating predetermined symbol areas preferentially on a frequency axis, mapping predetermined MBSs provided from the MBSFN zone to the predetermined symbol areas, and transmitting a first MBS among the predetermined MBSs to mobile stations located at an edge of the MBSFN zone. The first MBS is equal to a second MBS among MBSs provided from a neighbor MBSFN zone. The first MBS and the second MBS are transmitted to the same time zone according to a time division multiplexing (TDM) method. | 03-10-2011 |
20110090882 | METHOD AND APPARATUS FOR TRANSMITTING RECORDING INFORMATION FOR UPLINK TRANSMISSION IN MULTI BASE STATION MIMO SYSTEM - A PMI combination ratio (PCR) being used for generating a uplink precoding matrix W is transmitted by a base station to a mobile station. Using the PCR, a PMI maximizing transmission performance and PMI | 04-21-2011 |
20110098071 | Method for Releasing Resources Allocated by Persistent Scheduling - A method for releasing resources allocated by persistent scheduling is described. A base station (BS) inserts a persistent allocation release indication message into a control channel, wherein the persistent allocation release indication message includes at least one resource index indicating persistent allocation resources to a mobile station (MS), broadcasts the control channel, and releases the persistent allocation resources corresponding to the resource index. Since a release message for persistent allocation, a channel quality indicator channel, feedback polling allocation, etc. is inserted for transmission into a control channel which can be received by all MSs, overhead which occurs during resource release can be minimized irrespective of transmission rates varying with MSs. | 04-28-2011 |
20110103241 | MOBILE STATION APPARATUS AND METHOD FOR TRANSMITTING SIGNALS IN WIRELESS COMMUNICATION SYSTEM - A method for transmitting signal, at a mobile station, in a wireless communication system is provided. Inter-cell interference information may be different for each frequency partition according to using a FFR scheme. Also, a parameter for controlling interference level between base stations may be different for each frequency partition. The present invention is advantageous in that, when uplink transmission is performed, system throughput and cell edge-user throughput are improved and inter-cell interference level control is efficiently performed. | 05-05-2011 |
20110105164 | METHOD FOR AVOIDING INTER-CELL INTERFERENCE IN MULTI-CELL ENVIRONMENT USING MULTIPLE CODEBOOKS - A method is disclosed for avoiding inter-cell interference in a closed-loop multiple-input multiple-output (MIMO) system using a plurality of codebooks. A base station of a serving cell transmits information about codebooks used in an interfering cell among the plurality of codebooks to a mobile station. The transmission of the information may be made at the request of the mobile station. Alternatively, the mobile station may directly measure information about codebooks used in the interfering cell among the plurality of codebooks. The mobile station measures restricted precoding matrix indexes (PMIs) or requested PMIs based on the codebook information. The measured PMIs are transmitted to the interfering cell and are used to restrict the use of a PMI in the interfering cell. | 05-05-2011 |
20110149857 | METHOD OF TRANSMITTING USING PHASE SHIFT-BASED PRECODING AND AN APPARATUS FOR IMPLEMENTING THE SAME IN A WIRELESS COMMUNICATION SYSTEM - A method of transmitting data using a plurality of subcarriers in a multi-antenna wireless communication system is disclosed. More specifically, the method includes receiving feedback information from a mobile station (MS), performing channel encoding and modulation independently on user data to be transmitted by each antenna using the received feedback information, determining a phase shift-based precoding matrix for increasing a phase angle of the user data by a fixed amount, and performing precoding using the determined phase shift-based precoding matrix on the user data. | 06-23-2011 |
20110188441 | METHOD FOR ALLOCATING RESOURCE FOR MULTICAST AND/OR BROADCAST SERVICE DATA IN WIRELESS COMMUNICATION SYSTEM AND AN APPARATUS THEREFOR - The present invention relates to a wireless communication system, and more particularly, to a method for allocating a resource for multicast and/or broadcast service data in a wireless communication system and apparatus therefore. The present invention includes the steps of dividing a certain frequency band into a plurality of subbands, and allocating at least one subband to the MBS data from a subband having a lowest index among the plurality of subbands, wherein the MBS data is multiplexed with unicast data. | 08-04-2011 |
20110194650 | METHOD OF TRANSMITTING USING PHASE SHIFT-BASED PRECODING AND AN APPARATUS FOR IMPLEMENTING THE SAME IN A WIRELESS COMMUNICATION SYSTEM - A method of transmitting data using a plurality of subcarriers in a multi-antenna wireless communication system is disclosed. More specifically, the method includes receiving feedback information from a mobile station (MS), performing channel encoding and modulation independently on user data to be transmitted by each antenna using the received feedback information, determining a phase shift-based precoding matrix for increasing a phase angle of the user data by a fixed amount, and performing precoding using the determined phase shift-based precoding matrix on the user data. | 08-11-2011 |
20110216840 | SIGNAL TRANSMISSION METHOD AND SIGNAL RECEIVING METHOD IN A MULTI-INPUT MULTI-OUTPUT SYSTEM - Disclosed is a signal transmission method comprising a feedback information receiving step of receiving a transmission rate and channel state information for transmission from a receiving end, a step of generating a signal to be transmitted by using a multi-antenna in accordance with the transmission rate, a step of performing a precoding on the generated signal by using the precoding matrix of the nested structure selected from a predetermined codebook in accordance with the transmission rate, and a step of transmitting the precoded signal. Said codebook includes a precoding matrix set in which a pre-coding matrix according to a first number of streams is not included in a precoding matrix according to a second number of streams greater than the first number of streams. | 09-08-2011 |
20110222521 | METHOD AND USER EQUIPMENT FOR TRANSMITTING FEEDBACK INFORMATION - A method and User Equipment (UE) for transmitting feedback information are disclosed. The UE feeds back M best subbands to a Base Station (BS). Especially, the UE feeds back indication information indicating a combination of the M best subbands from among combinations each having M subbands produced out of a maximum number of subbands that can be allocated. Hence, coding of the feedback information is simplified. | 09-15-2011 |
20110249630 | METHOD OF RETRANSMISSION TO REDUCE THE OVERHEAD - A method of transmitting data in a wireless access system and a packet retransmitting method therein are disclosed. The present invention includes receiving an initial control message including information required for a packet retransmission from a base station, transmitting the packet to be provided with a service from the base station, and if a NACK (non-acknowledgement) signal is received from the base station, retransmitting the packet corresponding to the NACK signal to the base station using the information required for the packet retransmission and included in the initial control message. Therefore, since a separate control message needs not to be transmitted in case of packet retransmission,.it is able to save radio resources and reduce an overhead by retransmitting a packet via a previously allocated retransmission region without the separate control message. | 10-13-2011 |
20110250912 | METHOD FOR CONTROLLING UPLINK TRANSMISSION POWER IN WIRELESS COMMUNICATION SYSTEM AND AN APPARATUS THEREFOR - A method for setting uplink transmission power at a mobile station in a wireless communication system comprises the steps of: receiving information on the number of total streams received at a base station; and setting the uplink transmission power using the received number of total streams. In this case, the uplink transmission power is preferably a transmission power per stream (P | 10-13-2011 |
20110255436 | Method of Optimizing Comp Zone for Joint Processing Mode - A method of optimizing a CoMP Zone for a joint processing mode is disclosed. A method of optimizing a CoMP zone for a joint processing mode in a user equipment of a mobile communication system comprises transmitting information of at least one subband preferred by the user equipment among a plurality of subbands included in the CoMP zone, to a serving base station; receiving information of a specific subband included in the CoMP zone from the serving base station; and receiving data from at least one of the serving base station and neighboring base stations that support the CoMP, through a radio resource corresponding to the specific subband. | 10-20-2011 |
20110268073 | Method of Transmitting and Receiving Channel State Information Feedback in a Wireless Communication System - A method of transmitting and receiving channel state information feedback in a wireless communication system is disclosed. A method of transmitting channel state information (CSI) feedback by a user equipment receiver in a wireless communication system comprises mapping components of a CSI matrix to constellations; and allocating the mapped components to resource. | 11-03-2011 |
20110274200 | METHOD FOR TRANSMITTING/RECEIVING DATA IN A MULTIPLE-INPUT MULTIPLE-OUTPUT SYSTEM USING MULTI-CARRIER - A method for transmitting/receiving data in a Multiple Input Multiple Output (MIMO) communication system is disclosed. The data transmission method includes determining a precoding matrix to be a part of a phase-shift-based precoding matrix, determining a first diagonal matrix for phase shift to be a part of the phase-shift-based precoding matrix, determining a unitary matrix to be a part of the phase-shift-based precoding matrix, precoding a transmission symbol for each resource using the phase-shift-based precoding matrix to produce precoded data, and transmitting the precoded data, wherein the phase-shift-based precoding matrix is determined by the product of the precoding matrix, a Hermitian matrix of the unitary matrix, the first diagonal matrix, and the unitary matrix. | 11-10-2011 |
20110280290 | DATA TRANSMITTING AND RECEIVING METHOD USING PHASE SHIFT BASED PRECODING AND TRANSCEIVER SUPPORTING THE SAME - A method for performing a precoding based on a generalized phase shift or a precoding based on an extended phase shift in a Multi-Input Multi-Output (MIMO) system employing several sub-carriers, and a transceiver for supporting the same are disclosed. A phase-shift-based precoding matrix is generalized by multiplying a diagonal matrix for a phase shift by a unitary matrix for maintaining orthogonality between sub-carriers. In this case, a diagonal matrix part may be extended by multiplying a precoding matrix for removing an interference between sub-carriers by a diagonal matrix for a phase shift. By generalization and extension of the phase-shift-based precoding, a transceiver is more simplified, and a communication efficiency increases. | 11-17-2011 |
20110280291 | DATA TRANSMITTING AND RECEIVING METHOD USING PHASE SHIFT BASED PRECODING AND TRANSCEIVER SUPPORTING THE SAME - A method for performing a precoding based on a generalized phase shift or a precoding based on an extended phase shift in a Multi-Input Multi-Output (MIMO) system employing several sub-carriers, and a transceiver for supporting the same are disclosed. A phase-shift-based precoding matrix is generalized by multiplying a diagonal matrix for a phase shift by a unitary matrix for maintaining orthogonality between sub-carriers. In this case, a diagonal matrix part may be extended by multiplying a precoding matrix for removing an interference between sub-carriers by a diagonal matrix for a phase shift. By generalization and extension of the phase-shift-based precoding, a transceiver is more simplified, and a communication efficiency increases. | 11-17-2011 |
20110299622 | Low Overhead Feedback Scheme for Codebook Based Closed-Loop Mimo - The present invention relates to a Multi-Input Multi-Output (MIMO) communication system and more particularly, to a method for Correlation matrix feedback in a multi-cell wireless communication system. A method for transmitting correlation matrix feedback information of a mobile station considering adaptive feedback mode in a multi-cell wireless communication system according to one embodiment of the present invention comprises measuring a channel between the mobile station and a serving base station using a signal received from the serving base station; determining a first matrix indicating channel state information and a first precoder using the measured channel; generating a second matrix using a Fourier matrix and the first matrix; and transmitting feedback information including at least one of information of the first precoder and diagonal values of the second matrix. | 12-08-2011 |
20120021738 | Method for Setting Control Multi Point in Wireless Communication System and Apparatus Thereof - The present invention relates to a method for setting a control multi point of a serving cell in a wireless communication system. The serving cell selects more than one adjacent base station as a control multi point set based on first link information between terminals and the adjacent base stations received from the terminals. Furthermore, the serving cell: receives a pre-coding matrix index corresponding to the adjacent base stations which is selected by the terminals, selects more than one pre-coding matrix index from the received pre-coding matrix indexes according to a preset condition, generates a pre-coding matrix index list, and transmits pre-coding matrix index list to the corresponding base station. | 01-26-2012 |
20120027123 | METHOD FOR TRANSMITTING AND RECEIVING DATA IN WIRELESS COMMUNICATION SYSTEM - The present invention relates to a method for transmitting and receiving data in a wireless communication system. The method for transmitting data in a wireless communication system, according to one aspect of the present invention, comprises a step in which a base station transmits downlink data to a first terminal which supports a first system via a first region of a frame, and transmits downlink data to a second terminal which supports a second system via a second region which follows the first region corresponding to a frame offset on a time axis, wherein said frame offset is an offset of the start point of the frame for said first system and the start point of the frame for said second system, and said first region includes 3+6 (said frame offset-1) OFDM symbols. | 02-02-2012 |
20120039287 | TRANSMISSION METHOD OF DOWNLINK REFERENCE SIGNAL AND APPARATUS THEREOF - The present invention relates to a wireless communication system, and provides a method and an apparatus for transmitting a downlink reference signal in the wireless communication system. The method for enabling a base station to transmit the reference signal to a terminal using layers of 8 or less in accordance with one embodiment of the present invention comprises the steps of: transmitting data for the layers of 8 or less through a data domain of a downlink sub frame; and transmitting a reference signal for the layers of 8 or less on a fixed OFDM symbol of the downlink sub frame, wherein the reference signal is a DRS (Dedicated Reference Signal) which demodulates the data for the layers of 8 or less, and the reference signal for the layers of 8 or less is separated into 1st and 2nd groups, and reference signals of the 1st and 2nd groups can be multiplexed in a CDM (Code Division Multiplexing) method on one resource element, respectively. | 02-16-2012 |
20120106492 | METHOD AND APPARATUS FOR TRANSMITTING A SOUNDING SIGNAL IN A MULTIPLE INPUT MULTIPLE OUTPUT WIRELESS MOBILE COMMUNICATION SYSTEM - The present invention relates to a method for transmitting a sounding signal in a multiple input multiple output (MIMO) wireless mobile communication system. The method comprises: a step in which a terminal that supports a plurality of transmitting antennas receives, from a base station, at least one piece of uplink sounding transmission control information; and a step of transmitting a sounding signal using the received uplink sounding transmission control information, wherein said sounding transmission control information includes periodicity information for periodically repeating the transmission of the sounding signal, and a piece of antenna designation information for designating an antenna from among the plurality of transmitting antennas to be used in transmitting the sounding signal. | 05-03-2012 |
20120128050 | FEEDBACK SCHEME FOR MULTI-CELL INTERFERENCE MITIGATION CONSIDERATION LEGACY MOBILE USERS - The present invention relates to a Multi-Input Multi-Output (MIMO) communication system and more particularly, to a method for precoding matrix index (PMI) restriction/recommendation in a multi-cell wireless communication system. A method of codebook based precoding matrix index (PMI) feedback considering legacy mobile stations in a multi-cell wireless communication system comprises measuring a channel from at least one neighboring base station generating interference with a signal received from a serving base station; determining a first PMI in which the interference is maximized from PMIs included in a first codebook, wherein the first PMI is determined based on the measured channel; determining a first PMI group including PMIs having high correlation to the first PMI from the PMIs included in the first codebook; determining a second PMI in which the interference is maximized from PMIs included in a second codebook, where in the second codebook is for the legacy mobile stations; determining a second PMI group including PMIs having high correlation to the second PMI from the PMIs included in the second codebook; and transmitting feedback information including the first PMI, a first subset bit indicating the first PMI group, the second PMI and a second subset bit indicating the second PMI group to the serving base station. | 05-24-2012 |
20130279466 | TECHNIQUE FOR TRANSMITTING AND RECEIVING DOWNLINK REFERENCE SIGNALS - A technique for receiving and transmitting downlink reference signals is disclosed. When transmitting downlink data demodulation reference signals (DMRS) (or reference signals for downlink data demodulation) by using two or more layers, the DMRS of each layer may be multiplexed by using a code division multiplexing method and then transmitted. The DMRS for each of the two or more layers may be used for one user equipment or for two or more user equipments. And, downlink control signals for transmitting and receiving such DMRS may be configured to have the same format regardless of a single-user mode (or SU-MIMO mode) or a multi-user mode (or MU-MIMO mode), thereby being used. | 10-24-2013 |