Abstract: Provided is a radio communication method employed in a base station having plural antenna elements. The method includes the steps of: setting an inner zone and an outer zone by dividing a cell formed by the base station into two; determining whether a mobile station is located in the inner zone or the outer zone on the basis of a predetermined criterion; notifying the mobile station located in the inner zone of control information, including information on channel allocation and a communication method, through a broadcast channel; and notifying the mobile station located in the outer zone of control information through a dedicated channel by beamforming using the plural antenna elements.

Abstract: A radio communication system 1 according to an embodiment comprises: a pico cell base station PeNB provided in a communication area of a macro cell base station MeNB and having transmission power lower than transmission power of the macro cell base station MeNB. A resource division ratio is determined with respect to radio resources to be usable as a PDSCH, indicating a ratio of macro cell unusable PDSCH resources and macro cell usable PDSCH resources. The radio resources are assigned to a radio terminal connected to the macro cell base station MeNB, out of the macro cell usable PDSCH resources determined according to the determined resource division ratio. The resource division ratio is determined according to expected throughputs of each of cell edge terminals of the macro cell base station MeNB and the pico cell base station PeNB.

Abstract: A radio base station 100 includes fading rate measurement units 103a to 103n configured to measure a fading rate of a radio signal for each of the antenna elements 101a to 101n, the radio signal being received through the antenna elements; and a reference signal calculator 105 configured to output a reference signal used in an adaptive control of the directivity of the array antenna 101. The reference signal calculator 105 outputs the reference signal on the basis of a plurality of fading rates measured by the fading rate measurement units 103a to 103n.

Abstract: Provided is a channel information prediction system (10) which calculates a MIMO CSI prediction value as a predicted value of the MIMO CSI in the future by using the MIMO CSI and the transformation matrix indicating a transmission path characteristic between a transmitter (100) and a receiver (200) in an multi-antenna transmission system (1) using an antenna array formed by transmission antennas (#1 to #T) or reception antennas (#1 to #R) in the transmitter (100) and the receiver (200). The channel information prediction system (10) calculates the transformation matrix according to an array response or an array weight of the antenna array correlated with the arrival direction or the departure direction by using a direction estimation technique for estimating the arrival direction or the departure direction of the radio signal.

Abstract: A radio communication system 1 includes a pico-cell base station PeNB in stalled in a communication area of a macro-cell base station MeNB, having lower transmission power than the macro-cell base station MeNB, and expanded in its coverage. The macro-cell base station MeNB determines a degree of expanding the coverage of the pico-cell base station PeNB, according to an amount of usable PDSCH resources of the macro-cell base station MeNB.

Abstract: A macro-cell base station (MeNB) transmits, via a PDCCH in a first subframe, both allocation information indicating a radio resource allocated to a radio terminal (MUE) and subframe information indicating a second subframe which is later than the first subframe and in which an allocation is applied in accordance with the allocation information. The radio terminal (MUE) receives the allocation information and the subframe information from the macro-cell base station (MeNB) via the PDCCH in the first subframe. The macro-cell base station (MeNB) omits the transmission of the allocation information in the second subframe, while the reception unit on the terminal side omits the reception of the allocation information in the second subframe.

Abstract: A radio communication system 1 comprises a picocell base station PeNB placed within a communication area of a macrocell base station MeNB and has transmission output lower than the macrocell base station MeNB. A coverage of the picocell base station PeNB is expanded. A usable resource being a radio resource which a high-power base station is allowed to use as PDSCH is determined on the basis of a degree of expansion of coverage of a low-power base station.

Abstract: When receiving a signal from the antenna #1 (initially receiving a signal from an omnidirectional antenna), a guard interval correlator 12 calculates correlation of a guard interval portion of the received signal and an output measuring unit 13 measures a peak output of the guard interval correlator 12. A comparator 14 compares the peak output measured by the output measuring unit 13 with a preset threshold, and when the peak output falls below the preset threshold and outputs an antenna switching control signal to an antenna switch 11, and the antenna switch 11 switches to the antenna #2 having a different directivity.

Abstract: Provided is a channel information prediction system which uses a low ray element in a transformation MIMO CSI to calculate a first prediction filter coefficient. By using the obtained first prediction filter coefficient, the system executes a first prediction for predicting channel information upon a radio signal transmission in the future and suppresses a component of the ray contained in the low ray element. By using the low ray component in which the ray component is suppressed, the system executes a second prediction for predicting channel information upon a radio signal transmission in the future.

Abstract: A picocell base station (PeNB) uses a downlink control channel, the frequency band of which overlaps with the frequency band of the downlink control channel used by a macrocell base station (MeNB), to transmit downlink control information for controlling radio communication with a radio terminal (PUE) connected to the picocell base station (PeNB). The picocell base station (PeNB) comprises an X2 interface communication unit (140) which uses inter-base station communication to transmit to the macrocell base station (MeNB) usage control information for controlling the control channel usage that is the usage of a radio resource used as the downlink control channel by the macrocell base station (MeNB).

Abstract: Disclosed is a radio communication system which has: a radio base station (eNB#1), which forms a first cell, and which has a radio terminal connected to the radio base station (eNB#1), said radio terminal being in the first cell; and a radio base station (eNB#2), which forms a second cell, at least a part of which overlaps the first cell, and which has a radio terminal connected to the radio base station (eNB#2), said radio terminal being in the second cell. The radio base station (eNB#1) is so configured as to be switchable from being in the activated mode to being in the deactivated mode wherein power consumption is less than that in the activated mode. The radio base station (eNB#1) is controlled to be switched to be in the deactivated mode from being in the activated mode after the conditions, which indicate that the radio terminal (UE) connected to the radio base station (eNB#1) is connectable to the radio base station (eNB#2), are satisfied in the activated mode.

Abstract: If an unallocated PDSCH exists upon allocating downlink resource blocks to the radio terminal UE30-1, a radio base station eNB10-1 identifies a period corresponding to an area of the unallocated PDSCH (PDSCH unallocated period), and turns off a power amplifier 112 in the PDSCH unallocated period.

Abstract: After the radio base station eNB#2 receives a Configuration Update message from the radio base station eNB#1, the message including Deactivation Indication IE indicating that the radio base station eNB#1 is switched to the inactive state, the radio base station eNB#2 sends, to the radio base station eNB#1, a Cell Activation Request message for switching the radio base station eNB#1 to an active state depending on a condition of a radio terminal UE connected to the radio base station eNB#2.

Abstract: A radio base station eNB#1 comprises: a storage unit 130 which stores a handover parameter for controlling handover, in association with location information indicating a location in a communication area of the radio base station eNB#1; and a controller 120 which detects handover failure and control the storage unit in such a way as to adjust the handover parameter associated with the location information indicating a failure-detected location being a location of a radio terminal of which the handover failure is detected.

Abstract: A radio communication system (1) includes a pico-cell base station (PeNB) which is located in the communication area of a macro-cell base station (MeNB) and the transmission power of which is lower than that of the macro-cell base station (MeNB). For radio resources that can be used as PDSCH, a resource division ratio that is a ratio between unusable PDSCH resources, which cannot be used by the macro-cell base station (MeNB), and usable PDSCH resources, which can be used by the macro-cell base station (MeNB), is decided, and a radio resource is allocated, out of the usable PDSCH resources defined in accordance with the decided resource division ratio, to a radio terminal that is to connect to the macro-cell base station (MeNB). The resource division ratio is decided based on the traffic load of each base station.

Abstract: A radio base station includes: a propagation path characteristic acquisition unit which acquires propagation path characteristics between a radio communication terminal and a radio base station; and a channel controller which reports to the radio communication terminal that channel allocation information is transmitted by using a dedicated control channel if the acquired propagation characteristic satisfies a predetermined condition. After the channel control unit has reported to the radio communication terminal that the channel allocation information is transmitted by using an dedicated control channel, the channel control unit and a MAP processing unit transmit the channel allocation information by using an dedicated control channel instead of a broadcast control channel in the downstream frame.

Abstract: A channel estimation and prediction unit 18 estimates a channel and predicts a channel for a next transmission slot. An SVD unit 19 performs singular value decomposition on each channel prediction value. An eigenvalue calculation unit 20 calculates an eigenvalue in a slot, whereas an eigenmode quality calculation unit 21 calculates quality of each eigenmode based on the eigenvalue obtained from the eigenvalue calculation unit 20 and outputs the quality to a transmission adaptive control unit 22. The transmission adaptive control unit 22 recognizes frequency of channel variation based on variation of quality of a lower eigenmode and the likes, and corrects quality of a higher eigenmode to be a smaller value according to the frequency of channel variation being larger with respect to a slot length.

Abstract: A communication device according to the present invention includes a receiver configured to receive, through a radio link, packet signals each including a known signal indicating information known by the communication device and an unknown signal indicating information not known by the communication device, and a combiner configured to combine the packet signals while decreasing noise signals included in each of the packet signals. The communication device includes a correlation comparator configured to compare a correlation between the known signals in each of the packet signals with a correlation between the unknown signals in each of the packet signals, and a combining scheme controller configured to control a scheme of combining the packet signals, on the basis of the comparison result by the correlation comparator.

Abstract: A high power base station (100), when having detected a small cell (PC1) that is formed by a low power base station (200) and that is a source of interference, decides both a cell-edge band, which is used in a cell-edge area (MC1OUT), and a cell-center band, which is used in a cell-center area (MC1IN), in such a manner that the cell-edge and cell-center bands are different from each other. Further, the high power base station (100) transmits the decided cell-center band to the low power base station (200). The low power base station (200) then decides, as the small-cell band, the cell-center band received from the high power base station (100).

Abstract: An adaptive array wireless communication apparatus able to suitably select antenna elements, small in amount of processing, fast in convergence speed, and suitable for transmission/reception, and a method of the same, which controls the directionalities of array antenna elements based on array weights, controls an antenna element selecting unit 23 so that the antenna elements are intermittently determined, and adjusts a period of determination of the antenna elements based on information of the antenna elements determined at a controlling unit 26.