Abstract: A wireless communication system includes: a plurality of base stations wirelessly connected to a relay station; and the relay station comprising: a multi-element antenna including a plurality of antenna elements, wherein, among the plurality of antenna elements, a first antenna element is wirelessly connected to a first base station of the plurality of base stations, and a second antenna element is wirelessly connected to a second base station of the plurality of base stations; and a controller that switches at least one of the first antenna element and the second antenna element so as to be wirelessly connected to another base station of the plurality of base stations in response to an occurrence of an event.

Abstract: A wireless communication system includes a base station; and a relay station capable of wireless connection to the base station; wherein, in a case where a plurality of relay stations is accommodated with using a wireless connection, if a load state of traffic of the base station does not meet criteria, the base station selects at least one relay station, which is to perform the accommodation switching to meet the criteria, among the plurality of relay stations, and controls the selected relay station to perform the accommodation switching, and when the relay station is selected by the base station, the relay station switches a wireless connection to another base station.

Abstract: A wireless communication system includes: a plurality of base stations wirelessly connected to a relay station; and the relay station comprising: a multi-element antenna including a plurality of antenna elements, wherein, among the plurality of antenna elements, a first antenna element is wirelessly connected to a first base station of the plurality of base stations, and a second antenna element is wirelessly connected to a second base station of the plurality of base stations; and a controller that switches at least one of the first antenna element and the second antenna element so as to be wirelessly connected to another base station of the plurality of base stations in response to an occurrence of an event.

Abstract: A communication apparatus 101 having a plurality of antennas includes a controller that, in radio communication with another communication apparatus 103 on a plurality of channels by applying SDMA (Space Division Multiple Access), acquires information on communication performance of the another communication apparatus 103 and, based on the information, controls the radio communication that employs the SDMA.

Abstract: A wireless communication system includes a base station; and a relay station capable of wireless connection to the base station; wherein, in a case where a plurality of relay stations is accommodated with using a wireless connection, if a load state of traffic of the base station does not meet criteria, the base station selects at least one relay station, which is to perform the accommodation switching to meet the criteria, among the plurality of relay stations, and controls the selected relay station to perform the accommodation switching, and when the relay station is selected by the base station, the relay station switches a wireless connection to another base station.

Abstract: A communication apparatus 101 having a plurality of antennas includes a controller that, in radio communication with another communication apparatus 103 on a plurality of channels by applying SDMA (Space Division Multiple Access), acquires information on communication performance of the another communication apparatus 103 and, based on the information, controls the radio communication that employs the SDMA.

Abstract: When a scheduling executing section allocates a use downlink radio resource including in a frequency direction a frequency band, in which a known signal is not received by an uplink radio resource for known signal, from a downlink radio resource associated with the uplink radio resource for known signal to a communication terminal, a communication section generates a known signal to be received from the communication terminal in a frequency band of the use downlink radio resource in a pseudo manner when performing downlink communication with the communication terminal using the use downlink radio resource. The communication section controls transmission directivity in a plurality of antennas based on a new reception signal obtained by adding the pseudo known signal as a desired wave component to a reception signal that is received in the frequency band of the use downlink radio resource in the uplink radio resource for known signal.

Abstract: A setting unit sets a communication mode for different one or more counterpart communication apparatuses to a non-spatial multiplexing mode or a spatial multiplexing mode. Setting unit switches the setting of the communication mode for the different one or more counterpart communication apparatuses from the non-spatial multiplexing mode to the spatial multiplexing mode, on the basis of a capability of a communication system having an own apparatus and the different one or more counterpart communication apparatuses. A transmitting unit processes a transmitting signal to the different one or more counterpart communication apparatuses to output the processed signal to a plurality of antennas, on the basis of the set communication mode.

Abstract: The present invention relates to a wireless communication system and a communication control method. The wireless communication system includes: a wireless terminal; a plurality of base stations; and a host-side base station, wherein, in a case where CoMP transmission/reception is requested, the host-side base station decides base stations cooperating therewith for the CoMP transmission/reception, opens wireless lines for base stations under connection to the wireless terminal, and sends a same signal thereto, thereby performs the CoMP transmission/reception, and each of a plurality of the base stations functions as a relay device in a case of transferring the signal with the host-side base station through the wireless line.

Abstract: A scheduling executing section calculates a predicted value of a transmission gain at a time when controlling transmission directivity in a plurality of antennas based on a known signal to be received in a frequency band of a use downlink radio resource and performing downlink communication with a communication terminal, and determines a communication terminal to which the use downlink radio resource is allocated based on the predicted value.

Abstract: Upon receipt of sounding signals from a plurality of communication devices including a communication partner device, an evaluation value processing unit calculates an evaluation value indicative of a characteristic of a transmission path based on the sounding signals from the plurality of communication devices. A transmission scheme setting unit sets, based on the evaluation value, adaptive array transmission that achieves both null steering and beamforming or beamforming dedicated transmission as a transmission scheme to the communication partner device.

Abstract: When time at present is included in a high-traffic time period, an interference determining unit (37) determines that there is a possibility that a downlink signal to be received by any wireless terminal has interference with a pilot signal transmitted from a wireless base station. A pilot signal transmission control unit (40) controls the transmission of the pilot signal, which is included in an OFDMA frame or an OFDM frame. When it is determined that there is the possibility of interference, the pilot signal transmission control unit (40) stops the transmission of the pilot signal or reduces power of the pilot signal in a whole or a portion of a user data area.

Abstract: The present invention relates to a wireless communication system, a communication control method, and a relay station. The wireless communication system includes: a wireless terminal; a plurality of base stations; and a relay station, wherein the relay station defines a wirelessly communicable base station among the plurality of base stations as a candidate for a master station, in a case where a plurality of the candidates for the master station are present, acquires priority order setting information for setting priority orders of connection regarding the respective candidates for the master station, and sets the priority orders of the connection based on the priority order setting information. Then, in a case where the relay station has received a connection request from the wireless terminal, the control unit decides a candidate for the master station, which has a highest priority order of the connection, as an optimal master station.

Abstract: When time at present is included in a high-traffic time period, an interference determining unit (37) determines that there is a possibility that a downlink signal to be received by any wireless terminal has interference with a pilot signal transmitted from a wireless base station. A pilot signal transmission control unit (40) controls the transmission of the pilot signal, which is included in an OFDMA frame or an OFDM frame. When it is determined that there is the possibility of interference, the pilot signal transmission control unit (40) stops the transmission of the pilot signal or reduces power of the pilot signal in a whole or a portion of a user data area.

Abstract: A communication quality managing unit acquires or calculates a communication quality of a received signal at a different counterpart communication apparatus. A terminal model identifying unit identifies a model of the different counterpart communication apparatus. A switchover table storing unit stores a table, in which a communication quality corresponding to a requirement for switchover of a communication mode is set, for each model of the different counterpart communication apparatus. A switching unit refers to the table on the basis of the communication quality and the model of the different counterpart communication apparatus to switch a setting of a communication mode for a transmitting signal from a non-spatial multiplexing mode to a spatial multiplexing mode or from the spatial multiplexing mode to the non-spatial multiplexing mode. A transmitting unit processes the transmitting signal to output the processed signal to a plurality of antennas, on the basis of the set communication mode.

Abstract: A wireless communication device communicates with, using a plurality of antennas, a communication partner device including a plurality of antennas. The wireless communication device includes a communication unit, an interference intensity judgment unit, and a determination unit. The communication unit communicates with the communication partner device using the plurality of antennas and is configured to use a MIMO (multiple input multiple output) scheme when transmitting a signal to the communication partner device. The interference intensity judgment unit judges, based on predetermined criteria, whether or not an intensity of an interference wave included in a received signal at the communication partner device is high. The determination unit prohibits, upon the interference intensity judgment unit judging that the intensity of the interference wave is high, the communication unit from using the MIMO scheme when transmitting a signal.

Abstract: The present invention relates to a wireless communication system, a communication control method, and a relay station. The wireless communication system includes: a wireless terminal; a plurality of base stations; and a relay station, wherein the relay station defines a wirelessly communicable base station among the plurality of base stations as a candidate for a master station, in a case where a plurality of the candidates for the master station are present, acquires priority order setting information for setting priority orders of connection regarding the respective candidates for the master station, and sets the priority orders of the connection based on the priority order setting information. Then, in a case where the relay station has received a connection request from the wireless terminal, the control unit decides a candidate for the master station, which has a highest priority order of the connection, as an optimal master station.

Abstract: When switching a setting of a communication mode for a transmitting signal to a different communication apparatus from a non-spatial multiplexing mode to a spatial multiplexing mode on the basis of a first communication quality, a switching unit stores the first communication quality as a switchover reference value and then, when the first communication quality in a case of switching the setting of the communication mode for the transmitting signal to the different communication apparatus from the spatial multiplexing mode to the non-spatial multiplexing mode on the basis of a second communication quality is larger than the switchover reference value by a value which is equal to or more than a predetermined value, halts the switchover of the setting, to the spatial multiplexing mode, of the communication mode for the transmitting signal to the different communication apparatus until a predetermined requirement is satisfied.

Abstract: A communication level table storage unit stores a communication level table that defines correspondence between a communication level at least defined by MCS (modulation scheme and coding rate) and a range of required CINR at the communication level. A communication quality management unit obtains CINR of a received signal at another communication apparatus which is a communication partner. A setting unit refers to the communication level table, and when a difference between a representative value of a range of required CINR at a current communication level and a representative value of a range of required CINR of CINR at a communication level which is one level higher is more than or equal to a threshold value, sets a communication level such that the obtained CINR of the received signal is included in the range of required CINR.

Abstract: A radio base station allocates a large-interference channel or a small-interference channel to a radio terminal. The radio base station includes: a performance determination unit (121) which determines an interference can performance as a performance to cancellation the affects of interference in the radio terminal or the radio base station; and a channel allocation unit (125) which allocates the large-interference channel or the small-interference channel to the radio terminal in accordance with the interference cancellation performance. The channel allocation unit (125) allocates the small-interference channel with a higher priority than the large-interference channel as the interference cancellation performance increases.