Abstract: In a case where, although a radio base station (eNB 1-1) has established an SRS transmission frequency band, a serving radio terminal (UE 2-1) has transmitted, to the radio base station (eNB 1-1), an SRS by use of only a frequency band that is a part of the SRS transmission frequency band, the radio base station (eNB 1-1) allocates a downstream resource block the frequency band of which is included in the SRS transmission frequency band and further the frequency band of which is identical with the frequency band of the SRS received at the latest; then establishes, for the downstream resource block, a transmission weight based on the SRS received at the latest; and then uses the downstream resource block to transmit a radio signal.

Abstract: An eNB1-1 transmits an RRC Connection Reconfiguration message to UE2-1 to UE2-3, in which SRS parameters and an application timing parameter are set, the SRS parameters differ for each of the UE2-1 to the UE2-3 and the application timing parameter is common in the UE2-1 to the UE2-3. The UE2-1 to the UE2-3 receive the RRC Connection Reconfiguration message and recognize the SRS parameters and the application timing parameter set in the message. Furthermore, when an application timing of the SRS parameter arrives, the UE2-1 to the UE2-3 apply the SRS parameter to the SRS and transmit the SRS.

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: If the frequency band of an SRS from a serving radio terminal (UE 2-1) is identical with the frequency band of an SRS from a serving radio terminal (UE 2-2), a radio base station (eNB 1-1) transmits, to one of the serving radio terminals (UE 2-1, UE 2-2), an RRC connection reconfiguration message in which transmission halt request information has been set.

Abstract: A wireless base station (eNB1-1) uses in a differentiated manner, depending on the expected data amount of downlink transmission to the serving wireless terminal UE, the transmission of RRC Connection Reconfiguration messages in which SRS specific transmission request information is set, and the transmission of RRC Connection Reconfiguration messages in which SRS hopping transmission request information is set.

Abstract: The present invention provides a wireless base station (eNB1-1) that sets a first SRS transmission frequency band as a transmission frequency band for SRS at a first SSF timing and sets the first SRS transmission frequency band as the transmission frequency band for SRS at a second SSF timing, within the time for one frame. In this way, all frequency bands (allocatable frequency bands) for usable downstream resource blocks in wireless communications between the wireless base station (eNB1-1) and a serving wireless terminal (UE2-1) are covered by the first SRS transmission frequency band and the second SRS transmission frequency band.

Abstract: Disclosed is a wireless base station (eNB1-1) that sets to each serving wireless terminal (UE2) different frequency bandwidths (SRS transmission frequency bandwidths) that are used when said serving wireless terminals (UE2) send SRS at a predetermined special sub-frame timing. In addition the wireless base station (eNB1-1) sends the set SRS transmission frequency bandwidth information to the serving wireless terminals (UE2).

Abstract: A use signal determining section determines the use of a first known signal for array transmission control, when a downlink priority is higher than a threshold value. The use signal determining section determines the use of a second known signal for the array transmission control, when the downlink priority is lower than the threshold value. When the first known signal is used for the array transmission control for a communication terminal performing downlink communication therewith, a scheduling executing section determines to perform uplink communication with the communication terminal. When the second known signal is used for the array transmission control for a communication terminal performing downlink communication therewith, the scheduling executing section determines whether or not to perform uplink communication with the communication terminal by using an uplink priority for the communication terminal.

Abstract: A resource determination unit determines at least a part within any downlink subframe as a first resource and determines at least a part of an UpPTS (Uplink Pilot Timeslot) or a part of an uplink subframe as a second resource for transmitting an SRS (Sounding Reference Signal). A transmission path state estimation unit estimates a state of a transmission path to a wireless terminal based on a DRS (Demodulation Reference Signal) included in uplink user data after the first resource is determined and until it receives an SRS, and it estimates a state of the transmission path to the wireless terminal based on an SRS after it received the SRS.

Abstract: A transmission path state estimation unit estimates a state of a transmission path to a wireless terminal based on a DRS (Demodulation Reference Signal) included in uplink user data received from the wireless terminal when a re-sending request is received after transmission of an SRS is stopped. A transmission unit forms directivity of a plurality of antennas based on the estimated state of the transmission path and transmits downlink user data.

Abstract: A base station including at least one circuit configured to: receive a signal from a communication terminal via an array antenna; calculate a weight to be applied to the array antenna with respect to the communication terminal, based on a known signal supplied from the communication terminal and received by the circuit; transmit a signal to the communication terminal via the array antenna; determine m (m>1) communication terminals among the plurality of communication terminals, based on a first communication quality between base stations and a plurality of communication terminals, as communication-object candidates; cause to transmit control information, which is configured to cause the communication terminal to transmit the known signal, to the m communication terminals. Thus, the circuit may determine, as communication objects, l (1?l<m) communication terminals among the m communication terminals, based on quality of communication between the base station and the m communication terminals.

Abstract: A resource determination unit determines at least a part of an uplink part in a switch subframe as a second resource for a wireless terminal to transmit an SRS and determines at least a part within any uplink subframe as a third resource for the wireless terminal to transmit uplink user data including a DRS for a prescribed period. A transmission path state estimation unit estimates a state of a transmission path to the wireless terminal based on the DRS included in the uplink user data after the third resource is determined. A resource notification unit forms antenna directivity based on the estimated state of the transmission path and transmits a control message for notifying the wireless terminal of the determined second resource.

Abstract: A user data resource determination unit determines any sub carriers in any downlink subframe as a first resource from which downlink user data is transmitted to a wireless terminal. A sounding resource determination unit determines a part of an uplink part in a closest switch subframe preceding the determined downlink subframe as a second resource from which a wireless terminal transmits a sounding reference signal, and notifies the wireless terminal of the determined second resource. A transmission path state estimation unit estimates a state of a transmission path to the wireless terminal based on the sounding reference signal from the wireless terminal. A transmission unit forms directivity of a plurality of antennas based on the estimated state of the transmission path and transmits downlink user data.

Abstract: A communication device and methods are disclosed. A first throughput is calculated when a current modulation scheme and a current encoding rate is changed, and a second throughput is calculated when a current retransmission unit is changed. The current modulation scheme and the current encoding rate are changed to provide a changed modulation scheme and a changed encoding rate, if the first throughput is greater than or equal to the second throughput when prescribed conditions are met. The current retransmission unit is changed to provide a changed retransmission unit, if the first throughput is less than the second throughput. Information is transmitted to a communication device of a communication partner based on the changed modulation scheme, the changed encoding rate, and the changed retransmission unit.

Abstract: A use signal determining section determines the use of a first known signal for array transmission control, when a downlink priority is higher than a threshold value. The use signal determining section determines the use of a second known signal for the array transmission control, when the downlink priority is lower than the threshold value. When the first known signal is used for the array transmission control for a communication terminal performing downlink communication therewith, a scheduling executing section determines to perform uplink communication with the communication terminal. When the second known signal is used for the array transmission control for a communication terminal performing downlink communication therewith, the scheduling executing section determines whether or not to perform uplink communication with the communication terminal by using an uplink priority for the communication terminal.

Abstract: An eNB1-1 transmits an RRC Connection Reconfiguration message to UE2-1 to UE2-3, in which SRS parameters and an application timing parameter are set, the SRS parameters differ for each of the UE2-1 to the UE2-3 and the application timing parameter is common in the UE2-1 to the UE2-3. The UE2-1 to the UE2-3 receive the RRC Connection Reconfiguration message and recognize the SRS parameters and the application timing parameter set in the message. Furthermore, when an application timing of the SRS parameter arrives, the UE2-1 to the UE2-3 apply the SRS parameter to the SRS and transmit the SRS.

Abstract: If the frequency band of an SRS from a serving radio terminal (UE 2-1) is identical with the frequency band of an SRS from a serving radio terminal (UE 2-2), a radio base station (eNB 1-1) transmits, to one of the serving radio terminals (UE 2-1, UE 2-2), an RRC connection reconfiguration message in which transmission halt request information has been set.

Abstract: Disclosed is a wireless base station (eNB1-1) that sets to each serving wireless terminal (UE2) different frequency bandwidths (SRS transmission frequency bandwidths) that are used when said serving wireless terminals (UE2) send SRS at a predetermined special sub-frame timing. In addition the wireless base station (eNB1-1) sends the set SRS transmission frequency bandwidth information to the serving wireless terminals (UE2).

Abstract: In a case where, although a radio base station (eNB 1-1) has established an SRS transmission frequency band, a serving radio terminal (UE 2-1) has transmitted, to the radio base station (eNB 1-1), an SRS by use of only a frequency band that is a part of the SRS transmission frequency band, the radio base station (eNB 1-1) allocates a downstream resource block the frequency band of which is included in the SRS transmission frequency band and further the frequency band of which is identical with the frequency band of the SRS received at the latest; then establishes, for the downstream resource block, a transmission weight based on the SRS received at the latest; and then uses the downstream resource block to transmit a radio signal.

Abstract: A wireless base station (eNB1-1) uses in a differentiated manner, depending on the expected data amount of downlink transmission to the serving wireless terminal UE, the transmission of RRC Connection Reconfiguration messages in which SRS specific transmission request information is set, and the transmission of RRC Connection Reconfiguration messages in which SRS hopping transmission request information is set.