Patent application number | Description | Published |
20110211519 | WIRELESS COMMUNICATION SYSTEM, BASE STATION AND NETWORK CONTROL APPARATUS - In a time slot in which a first base station for performing a multicast transmission executes the multicast transmission, a second base station which does not perform the multicast transmission does not perform a unicast data transmission. The time slot in which the first base station performs the multicast transmission is notified to the second base station from a multicast control apparatus for performing scheduling of the multicast transmission to the first base station. Information to receive the multicast transmission is notified from the second base station to a terminal connected to the second base station. | 09-01-2011 |
20110211560 | MOBILITY CONTROL METHOD MITIGATING INTER CELL INTERFERENCE AND BASE STATIONS WHICH ADOPT THE METHOD - Interference applied to neighbor cells during terminal handovers can be reduced in wireless communication systems containing base stations having different cell sizes. A serving cell makes handover judgment criteria easier based on pre-acquired cell size information on its own cell and cell size information of neighbor cells in order to facilitate terminal handovers from a base station with a large cell size to a base station with a small cell size. The serving cell finds evaluation function values based on the propagation state (e.g. reference signal received power) between the terminal and target cell, and the interference and load information exchanged between the base stations, and selects the terminal for handover by comparing the evaluation function value with the handover criteria value. The system selects a target cell having a good effect in lowering interference such as a cell with large reference signal received power acquired from a terminal, to serve as the handover destination. | 09-01-2011 |
20110212744 | TRANSMIT POWER CONTROL METHOD FOR RADIO COMMUNICATION SYSTEM AND RADIO BASE STATION DEVICE - A communication device includes pilot signal sending part and transmit power control part and holds a criterion value indicating target channel quality for mobile stations within the area covered by the base station. It creates quality data from reports from one or plural mobile stations, stores the quality data, creates a first representative value indicating average channel quality for the mobile station(s) from the stored quality data, and changes the transmit power depending on the result of comparison between the first representative value and the criterion value. It creates a second representative value indicating distribution of low channel quality from the stored quality data and updates the criterion value depending on the result of comparison between the second representative value and the criterion value. | 09-01-2011 |
20110244866 | WIRELESS COMMUNICATION SYSTEM AND LOAD BALANCING AWARE HANDOVER METHOD THEREFOR - An object of the invention is to provide a wireless communication system in which the load of each cell and interference between cells are taken into account. In a handover-candidate base station and a handover-source base station, parameters for interference-reducing scheduling and handover facilitating processing are adjusted based on the mutual load information. When the handover-candidate base station, to be used for load balancing, is a large-diameter cell, transmit power control and frequency scheduling are adjusted by taking account of the load state at a cell edge. When the handover-source base station has a small-diameter cell, the number of terminals to be handed over is adjusted by taking account of the load state of the handover-candidate base station. Thus, both of interference control and load balancing are achieved. | 10-06-2011 |
20110310758 | Method of Resource Assignment for Radio Communication System and Base Station Apparatus - A method for assigning resources of a radio communication system that is aimed at relaxing interference between cells and that is applicable even in the case where femtocell base stations are installed within a macrocell base station area, and a radio base station apparatus. A transmit power limitation that limits an allocatable resource for each subband consisting of one or plural sub-carriers is decided, resource assignment is preformed on a mobile terminal on a subband-by-subband basis by a scheduler so that the transmit power limitation may be satisfied, and the transmit power limitation is altered based on an estimation result of an interference quantity from surrounding cells. | 12-22-2011 |
20110317742 | BASE STATION - A cellular radio communication system includes a first mobile terminal, a base station that performs radio communication with first mobile terminals, a second mobile terminal, and a second base station that performs radio communication with second mobile terminals. In the downlink communication, the base station selects a high data rate mode when the radio interference from the base station to the second mobile terminals that are located close to an edge of a communication area of the second base station is small. The base station selects an interference mitigation mode in the downlink communication when the radio interference from the base station to the second mobile terminals that are located close to the edge of the communication area of the second base station is large. Thus, inter-cell interference control can be performed in collaboration with base stations in the radio communication system without having communication interface between the base stations. | 12-29-2011 |
20120028630 | Base Station and Cellular Wireless Communication System - A femtocell base station collects the terminal distribution within the cell and selects terminals to represent the cell-center and the cell-edge from among the terminals within the cell. The femtocell base station also calculates maximum transmit power for the respective the cell-center and cell-edge terminals allowable by the macrocell base station. The femtocell base station sets the respective transmit power of the cell-center and the cell-edge in a range that will not exceed the maximum transmit power, adjusts the transmit power control parameter to allow control by the terminal at the power value that was set, and notifies the terminal. Communication with high throughput can in this way be attained for terminals in cells within the femtocell base station during uplink communications to the femtocell base station, and interference applied to the terminals in the macrocell base station can be suppressed. | 02-02-2012 |
20120129527 | WIRELESS COMMUNICATION SYSTEM AND METHOD FOR WIRELESS COMMUNICATION - When a femto cell base station detects an intense uplink interference, the femto cell base station autonomously extends the femto cell so as to raise a probability that a mobile terminal around the original femto cell may be connected to the femto cell base station. If the mobile terminal connects to the femto cell base station, the uplink interference is reduced and total throughput is improved. Additionally, if a resultant effect of interference reduction is low, the femto cell base station returns the mobile terminal, which is connected to the femto cell base station due to the extension of the femto cell, to the original connection destination. If an evaluative criterion meets a predetermined condition, the femto cell base station restores the extended femto cell to the original size. These actions prevent degradation of performance caused by concentration of the connections of mobile terminals to the femto cell base station. | 05-24-2012 |
20120213148 | WIRELESS COMMUNICATION SYSTEM HAVING RELAY DEVICE, AND METHOD FOR SELECTING RELAY TERMINAL - In wireless communication systems into which a relay device has been introduced, although terminal reception quality increases, data transmission by relay devices with low contribution causes interference in other data transmission, which invites a decrease in reception quality of electromagnetic waves received by terminals. As a way to resolve the abovementioned issue, as one embodiment of the present disclosures, a wireless relay station is configured so as to receive a plurality of data addressed for wireless terminals from a wireless base station, and to transmit data that are selected from the aforementioned received plurality of data and that are addressed to the aforementioned wireless terminals which are the destinations of transmission. As a result, interference towards other data transmission and reception caused by data transmission of a relay device can be suppressed, and the reception quality of electromagnetic waves received by the terminal can be increased. | 08-23-2012 |
20120281569 | BASE STATION, INTERFERENCE CONTROL METHOD AND RADIO COMMUNICATION SYSTEM - Timing division multiplexing is conducted between the cells to avoid intercell interference. Transmission timing in a time slot pattern has a given interval. A base station determines the transmission timing based on measured uplink interference power. For example, an uplink time slot pattern in which the measured uplink interference power is smaller is selected. A downlink time slot pattern is assigned so that a response to HARQ is returned at that timing. If traffic is busy, additional time slot pattern may be assigned. In determination of the traffic volume, for example, the queued buffer size, the number of connected terminals, or the number of connections to a higher-level device can be used. Assignment timing can be an initial setup time, or a fluctuation detection time of a channel which can be realized by collection of report information on a downlink communication quality, periodic monitor of uplink interference information. | 11-08-2012 |
20130070625 | WIRELESS COMMUNICATION SYSTEM AND BASE STATION - To reduce an uplink interference in a network with a first base station of a large output and a second base station of a small output. Detecting the interference, the second base station urges the first base station to hand over a terminal causing it to the second base station. Multiple base stations and one or more terminals exist in this system, each terminal connects with one base station, and a serving base station is changed according to a communication state of each terminal. If the different second base station other than the first base station to which the terminal connects detects a large interference, the second base station will multicast transmit information for urging handover to the base stations except itself. The base station having received the information specifies a terminal giving the interference to the second base station, and makes it to be handed over thereto. | 03-21-2013 |
20130190024 | BASE STATION, SYSTEM, AND METHOD OF UPLINK INTERFERENCE COORDINATION IN WIRELESS COMMUNCIATION - A macro base station includes a communication prohibited period setting unit of setting an uplink communication prohibited period to a user equipment belonging to the base station, and prohibits an uplink communication from the user equipment to a wireless communication base station per se during the uplink communication prohibited period. The user equipments belonging to the wireless communication base station per se and the second base station are divided into plural groups, and the uplink communication prohibited period is set to different time periods for the respective groups. Thereby, a communication characteristic is prohibited from being deteriorated at the second base station by an interference affected with the second base station separately from the first base station by the user equipment communicating with the first base station in the uplink communication. | 07-25-2013 |
20140364122 | WIRELESS COMMUNICATION SYSTEM AND METHOD FOR WIRELESS COMMUNICATION - When a femto cell base station detects an intense uplink interference, the femto cell base station autonomously extends the femto cell so as to raise a probability that a mobile terminal around the original femto cell may be connected to the femto cell base station. If the mobile terminal connects to the femto cell base station, the uplink interference is reduced and total throughput is improved. Additionally, if a resultant effect of interference reduction is low, the femto cell base station returns the mobile terminal, which is connected to the femto cell base station due to the extension of the femto cell, to the original connection destination. If an evaluative criterion meets a predetermined condition, the femto cell base station restores the extended femto cell to the original size. These actions prevent degradation of performance caused by concentration of the connections of mobile terminals to the femto cell base station. | 12-11-2014 |