Patent application number | Description | Published |
20080298491 | Apparatus and method for detecting signal based on QR-decomposition in multiple input multiple output wireless communication system - An apparatus and a method are provided for detecting N number of TX signals in a MIMO wireless communication system. The apparatus includes an RF processor, a channel estimator, and a signal detector. The RF processor converts signals, received through multiple antennas, into baseband signals. The channel estimator estimates channel information of the respective antennas by using the received signals. The signal detector arranges the baseband signals of the respective antennas on the basis of the channel information, calculates a threshold value of each stage, and selects symbols with a cumulative metric smaller than or equal to the threshold value as candidates at each stage, to detect a TX signal vector with N number of symbols. | 12-04-2008 |
20090028265 | Apparatus and method for detecting signal by maximum likelihood - An apparatus and method for detecting a signal in a receiver by maximum likelihood (ML) are provided, in which symbols are detected according to the number of transmit antennas of a transmitter and a modulation scheme, channels are estimated, an equivalent channel matrix corresponding to the estimated channels is determined, a permuted equivalent channel matrix is determined by multiplying the equivalent channel matrix by a predetermined permutation matrix, the permuted equivalent channel matrix is QR decomposed, a hard decision is performed on predetermined symbols among the detected symbols using a received signal resulting from the QR decomposition, and the log likelihood ratios (LLRs) of the hard-decided symbols are determined. | 01-29-2009 |
20090086840 | Apparatus and method for transmitting feedback information in communication system - Disclosed is a system and method for transmitting feedback information in a communication system. A receiver calculates a minimum distance of each two symbol vectors among all symbol vectors which can be received through a k | 04-02-2009 |
20090097423 | APPARATUS AND METHOD FOR TRANSMITTING/RECEIVING RESOURCE ALLOCATION INFORMATION IN A COMMUNICATION SYSTEM - An apparatus and method for transmitting/receiving resource allocation information in a communication system are provided. In the method of transmitting resource allocation information, at least one of a plurality of FDD UL FA resources is divided into a plurality of segment regions, and first resource allocation information is transmitted to mobile stations through a plurality of TDD DL FA resources. The first resource allocation information indicates, among the plurality of segment regions, each of segment regions corresponding to the TDD down link FA resources. | 04-16-2009 |
20090116590 | APPARATUS AND METHOD FOR DETECTING SIGNAL IN MULTI-ANTENNA SYSTEM - A method and an apparatus for detecting a signal in a multi-antenna system using a spatial multiplexing are provided. The apparatus includes at least one antenna for receiving a signal, a channel estimator for estimating a channel using the received signal, a detector for calculating multiplication values commonly used to determine a Euclidean distance using the receive signal and channel information and for detecting a transmitted signal by calculating Euclidean distances of one or more candidate symbols using the receive signal and the determined multiplication values and a decoder for demodulating and decoding the detected signal. Hence, the computational complexity of the signal detection can be mitigated. | 05-07-2009 |
20090154335 | RECEIVING APPARATUS AND METHOD FOR SINGLE CARRIER FREQUENCY DIVISION ACCESS SYSTEM - A receiver and a receiving method for a Single Carrier Frequency Division Multiple Access (SC-FDMA) system are provided. The receiver includes a matrix selector for selecting a constant channel matrix according to a Multiple-Input Multiple-Output (MIMO) reception scheme, a channel equalizer for equalizing a multi-path channel to a specific path channel in a frequency domain by using the constant channel matrix, and a MIMO detector for detecting a Euclidean distance of transmittable symbols from a time-domain Transmit (Tx) signal by using the channel equalized in the frequency domain and then for selecting a symbol having a minimum distance. | 06-18-2009 |
20090262871 | Receiver and method for detecting signal in multiple antenna system - Provided are a receiver and a method for detecting a signal in a multiple antenna system. The receiver includes a filter coefficient calculator and a signal detector. After separating a first signal portion and a second signal portion, the filter coefficient calculator calculates an MMSE filter coefficient using a Matrix Inversion Lemma such that an inverse matrix of the first signal portion has a predetermined constant value regardless of a repetition signal detection process. The signal detector detects a relevant transmission signal from an interference-removed reception signal using the MMSE filter coefficient. | 10-22-2009 |
20090286494 | Iterative tree search-based precoding technique for multiuser mimo communication system - An iterative tree search-based preceding method for a multi-user Multi-Input Multi-Output (MIMO) communication system includes determining a reference value of a cumulative branch metric of a candidate symbol, eliminating candidates having values that exceed the determined reference value of the cumulative branch metric of the candidate symbol, and registering values, which do not exceed the determined reference value of the cumulative branch metric of the candidate symbol, as entries, and selecting the least value from the values registered as the entries. Thereby, the method has low complexity and similar performance compared to an existing Sphere Encoding (SE) technique. | 11-19-2009 |
20090286546 | Apparatus and method for avoiding interference between base station and relay station when using full duplex relay in a multi hop relay system - An apparatus and method for avoiding interference between a base station and a relay station when using full duplex relay in a multi-hop relay wireless communication system are provided. An operation of a mobile station includes measuring an strength of a receive signal from a base station and an strength of a receive signal from an relay station, calculating a receive signal strength ratio of base station to relay station by dividing the strength of the receive signal from the base station by the strength of the receive signal from the relay station, determining if interference occurs using the receive signal strength ratio, and transmitting a control message representing if interference occurs. | 11-19-2009 |
20100046655 | APPARATUS AND METHOD FOR TRANSMITTING AND RECEIVING IN A MULTI-ANTENNA SYSTEM - Apparatuses and methods for transmitting and receiving in a multi-antenna system are provided. A receiver for reducing a quantization error of channel information feedback in a multi-antenna system includes a restore vector generator for selecting a codeword c | 02-25-2010 |
20100165971 | SCHEDULING METHOD OF WIRELESS COMMUNICATION SYSTEM AND APPARATUS ADAPTED THERETO - A scheduling method and an apparatus adapted thereto are disclosed that can allocate sub-carriers to a terminal at the cell edge in a wireless communication. The scheduling method includes, calculating average interference and instantaneous interference of at least two terminals for a sub-carrier, determining whether an interference for the sub-carrier is partial interference, and allocating a corresponding sub-carrier serving as transmission resource to a terminal having a higher ratio of the instantaneous interference compared to the average interference than the other terminal if an interference for the sub-carrier is partial interference. | 07-01-2010 |
20100177839 | METHOD OF DIRTY PAPER CODING USING NESTED LATTICE CODES - A method of Dirty Paper Coding DPC using nested lattices is disclosed. The complexity of DPC can be reduced by scaling nested lattices and mapping interference to a lattice point of the scaled lattice. | 07-15-2010 |
20100183089 | METHOD FOR SIGNAL TRANSMISSION-RECEPTION IN A MULTI-USER MULTIPLE TRANSMIT AND MULTIPLE RECEIVE ANTENNA RADIO COMMUNICATION SYSTEM - An apparatus and method for signal transmission-reception in a multi-user multiple transmit and multiple receive antenna radio communication system are provided. An aspect of the present invention is to enhance reception performance and increase the communication channel throughput. This is achieved by applying a new sequence of operations including a vector perturbation procedure along with an efficient perturbation vector searching technique based on single-dimensional optimization of a decision function. In addition, the method ensures simple implementation of a subscriber station receiver. The SS receiver is implemented as independent channels for processing signals of different receive antennas. The receiver can be implemented even if each subscriber station has only one receive antenna. Accordingly, the method proves highly efficient in virtually any propagation environment. | 07-22-2010 |
20100271932 | APPARATUS AND METHOD FOR COMPENSATING FOR PHASE ERROR IN WIRELESS COMMUNICATION SYSTEM - An apparatus and method for compensating for a phase error in a wireless communication system are provided. The apparatus includes a reception modem, a transmission modem, a Common Phase Error (CPE) compensator, a first channel estimator, a phase compensator, and a second channel estimator. The reception modem demodulates and decodes a signal received. The transmission modem encodes and modulates a signal for transmission. The CPE compensator compensates for phase errors of at least two symbols constituting a signal. The first channel estimator estimates channels for respective bursts. The phase compensator compares phases for the channels for the respective bursts with each other and compensates for a phase difference between at least two bursts. The second channel estimator estimates an interference channel. | 10-28-2010 |
20100273498 | APPARATUS AND METHOD FOR INTERFERENCE MITIGATION IN A WIRELESS COMMUNICATION SYSTEM - An apparatus and method for mitigating inter-cell interference in a macro Base Station (BS) of a wireless communication system having at least one femto cell are provided. The method includes restricting the use of at least one code among at least one available code when forming a beam by resource block, constructing a codebook set for each resource block, when feedback information is received from at least one Mobile Station (MS), allocating a resource to the MS in consideration of the feedback information, determining a weight for forming a beam to the MS in consideration of the codebook set for each resource block and the resource allocated to the MS, and forming the beam to the MS using the weight. | 10-28-2010 |
20110070881 | ANTI-INTERFERENCE APPARATUS AND METHOD IN WIRELESS COMMUNICATION SYSTEM - The present invention relates to an apparatus and method for reducing the interference caused by a femtocell in a wireless communication system. The method comprises the steps of: measuring the intensity of a signal received from a terminal when the transmission mode is deactivated; and controlling the transmission mode to be activated according to the signal intensity, and thus has the advantage of decreasing the influence effects caused by the femtocell and reducing the power consumption in a femto base station. | 03-24-2011 |
20120076158 | METHOD AND APPARATUS FOR TRANSMITTING/RECEIVING DATA IN SINGLE CARRIER FREQUENCY DIVISION MULTIPLE ACCESS SYSTEM - The present invention provides a method for transmitting and receiving data in a single carrier frequency division multiple access system to which a precoding matrix is applied, and to a transmitting/receiving apparatus for same. The method for transmitting data comprises the steps of: applying selected mapping algorithm (SLM) sequences of an SLM sequence subset corresponding to a precoding matrix, to respective data; selecting the SLM sequence in which each of the applied data has the smallest peak to average power ratio (PAPR) value; and transmitting the index of the selected SLM sequence and data to which the selected SLM sequence is applied. The method for receiving data, to which a precoding matrix is applied, comprises the steps of: receiving the index of the SLM sequence selected from the SLM sequence subset corresponding to the precoding matrix, and data to which the selected SLM sequence is applied; and removing the SLM sequence from the data to which the SLM sequence is applied using the SLM sequence indicated by the index, in order to recover data. | 03-29-2012 |
20120176915 | METHOD AND APPARATUS FOR CONTROLLING UPLINK TRANSMISSION POWER IN WIRELESS COMMUNICATION SYSTEM - A method for controlling uplink transmission power in a wireless communication system is provided. The method includes estimating a downlink path loss, determining a target Signal to Noise Ratio (SNR) depending on the downlink path loss, determining an amount of power to compensate for a difference between the target SNR and an estimated SNR, and transmitting a power control message including a Transmit Power Control (TPC) command value to a terminal based on the determined amount of power. | 07-12-2012 |