Patent application number | Description | Published |
20090213965 | MIMO MULTIPLEXING COMMUNICATION SYSTEM AND A SIGNAL SEPARATION METHOD - A disclosed receiver in a MIMO multiplexing communication system, in which plural signals are simultaneously transmitted from plural transmitting antenna branches using the same frequency, and the transmitted signals are retrieved by receiving signals at plural receiving antennas, separating the received signals and searching for proper symbol metrics for each branch, comprises a QR decomposer for QR decomposing the received signals to orthogonalize the transmitted signals; a symbol replica candidate ranking unit for subtracting surviving symbol replica candidates from the QR decomposed received signals to get remaining received signals and rank the remaining signals in the increasing order of expected branch metrics of the remaining received signals; a symbol replica candidate selector for selecting symbol replica candidates in the ranked order; a branch metric calculator for calculating the branch metrics of the selected symbol replica candidates; and a threshold comparator for comparing the calculated branch metrics with a predetermined threshold; wherein if a calculated branch metric is larger than the predetermined threshold, the branch metric and successive branch metrics are deleted without further searching. | 08-27-2009 |
20100113059 | RADIO ACCESS NETWORK APPARATUS AND THE METHOD - A radio access network apparatus comprises a means for judging whether or not a mobile station belongs to the area of a cell end and a means for allocating the frequency of the cell end to the mobile station of the cell end and allocating the frequency of a non-cell end different from the frequency of the cell end to a user in an area other than the cell end. The frequency of the cell end includes a first band different for each cell. The frequency of the non-cell end includes a second band common to a plurality of cells including its own cell and a third band equal to the frequency of the adjacent cell end. | 05-06-2010 |
20100150274 | Method and System for Determining a Signal Vector - A method for determining a signal vector comprising a plurality of components from a received signal vector is provided comprising performing a QR decomposition of a channel matrix characterizing the communication channel via which the signal vector was received and being expanded by variance information about the noise on the communication channel carrying out a plurality of determination steps using the QR decomposition of the expanded channel matrix, wherein in each step a set of possible sub-vectors of the signal vector is determined and wherein in each step, the number of possible sub-vectors in the set is lower than a predefined maximum number, and selecting one vector of the set of possible sub-vectors determined in the last step of the plurality of determination steps as the signal vector. | 06-17-2010 |
20100254326 | BASE STATION APPARATUS, USER APPARATUS AND COMMUNICATION CONTROL METHOD - The user apparatus is provided with a plurality of antennas, and transmits a reference signal in the uplink by switching the plurality of antennas. The plurality of antennas are associated with subframes transmitted in the uplink. The base station apparatus in a radio communication system to which transmission diversity is applied in the uplink includes: a reception level storing unit configured to store a measured reception level of the reference signal for each antenna of each user apparatus; and a scheduler configured to perform, based on the reception level of the reference signal transmitted for each antenna of each user apparatus stored in the reception level storing unit, scheduling for determining a user apparatus to be assigned to a subframe associated with the antenna. | 10-07-2010 |
20110090893 | MOBILE COMMUNICATION SYSTEM, RECEIVER AND METHOD - A transmitter in a mobile communication system code-multiplexes transmission symbols together with spreading codes, performs inverse Fourier transform and transmits the result from multiple transmit antennas. A receiver in the mobile communication system performs Fourier transform on signals received at multiple receive antennas, extracts signal components of individual subcarriers and estimates symbols in accordance with a QR decomposition algorithm. A unitary matrix is derived such that a product of a spreading matrix including spreading elements as its elements and a channel matrix representing radio channel states is equal to a product of the unitary matrix and a triangular matrix. A reception vector, a unitary matrix and a triangular matrix are used to estimate symbol candidates transmitted from individual transmit antennas. | 04-21-2011 |
20110092241 | BASE STATION APPARATUS, USER EQUIPMENT TERMINAL, AND COMMUNICATION CONTROL METHOD - A base station apparatus includes a transmit diversity setting unit configured to set a transmit diversity mode to be applied to a user equipment terminal; a reception quality calculating unit configured to determine reception quality corresponding to the transmit diversity mode based on the transmit diversity mode set by the transmit diversity setting unit; a scheduling unit configured to determine a user equipment terminal to which a radio resource is to be allocated based on the reception quality determined by the reception quality calculating unit; and a notifying unit configured to notify the user equipment terminal to which the radio resource is allocated as determined by the scheduling unit of the transmit diversity mode to be applied. | 04-21-2011 |
20110256897 | BASE STATION APPARATUS, USER EQUIPMENT AND PRECODING METHOD - The present invention provides a base station apparatus capable of preventing degrading of throughput performance even when feedback information amount on precoding in uplink MIMO transmission is reduced. This base station ( | 10-20-2011 |
20110289293 | SEMICONDUCTOR DEVICE - There is provided a semiconductor device which is simple in configuration and resistant to tampering. A user input unit receives an authentication code input by a user. A CPU determines whether a user's access is legal based on the input authentication code and activates an enable signal if the user's access is legal. A normal row decoder decodes the row address specified by the CPU and selects a normal memory cell of any row based on the result of decode. A redundancy row decoder prohibits the selection by the normal row decoder when the specified row address agrees with the row address of a predetermined normal memory cell only if the enable signal is activated and selects a redundant memory cell of any row. | 11-24-2011 |