Abstract: A base station communicates with a user device transmitting an uplink signal based on a single-carrier transmission scheme. The base station includes a frequency hopping determining unit configured to determine whether to apply frequency hopping to the user device based on radio-wave propagation information from the user device and a traffic type of data to be transmitted by the user device; a scheduler configured to allocate frequencies to the user device based on uplink channel reception conditions of the user device; and a reporting unit configured to report allocation information indicating resource units allocated by the scheduler to the user device. When the frequency hopping determining unit determines to apply the frequency hopping to the user device, the scheduler allocates, to the user device, resource units with different frequency bands in different slots.

Abstract: To suppress deterioration of retransmission efficiency and retransmit a transmission signal efficiently, provided are a base station apparatus which divides, in a retransmission block dividing section, a transmission signal into retransmission blocks according to a retransmission block table with which are registered the numbers of the retransmission blocks, each of the transmission blocks is a retransmission unit of a transmission signal, the numbers of the retransmission blocks are required numbers corresponding to the number of transmission antennas and the system bandwidth in case that the maximum value of the size of the retransmission block is fixed to a certain value, and retransmits in downlink transmission signals associated with the divided retransmission blocks, and a mobile terminal apparatus which receives the transmission signals associated with the retransmission blocks from the base station apparatus, and combines the retransmission blocks to restore the transmission signal prior to division.

Abstract: A base station determines both a transmission interval between scheduling requests which a mobile station transmits before transmitting uplink data and information about radio resources used for transmitting the scheduling requests, based on the status of the mobile station and/or QoS information transmitted from the mobile station. The mobile station generates the scheduling requests. The mobile station controls the transmission of the scheduling requests based on the transmission interval and the radio resources. The mobile station transmits the scheduling requests. The base station detects correlation based on the scheduling requests which are transmitted from the mobile station based on the transmission interval and the radio resources, and feeds delay information back to the mobile station. The mobile station maintains synchronization based on the delay information transmitted from the base station.

Abstract: A mobile station includes: a physical channel segmentation unit to receive radio signals including multiple orthogonal signals which are orthogonal to each other, and multiple non-orthogonal signals which are not orthogonal to each other; and data demodulating/decoding units to extract the non-orthogonal signal addressed to the mobile station from the multiple non-orthogonal signals by demodulating and cancelling the radio signal addressed to another mobile station by use of the orthogonal signals included in the radio signals received by the physical channel segmentation unit, and demodulate the signal included in the orthogonal signals and addressed to the mobile station, and the extracted non-orthogonal signal addressed to the mobile station.

Abstract: To provide a user terminal, radio base station apparatus, radio communication system and radio communication method that support increases in the number of users, a user terminal is provided with a reception section that receives a downlink control signal multiplexed into radio resources from the starting OFDM symbol to a predetermined OFDM symbol in a subframe, and a downlink control signal subjected to frequency division multiplexing with a downlink data signal into radio resources after the predetermined OFDM symbol, a retransmission check section that performs a retransmission check on the downlink data signal based on the downlink control signal subjected to frequency division multiplexing to output a retransmission response signal, and a selection section that selects a radio resource of an uplink control channel used in transmission of the retransmission response signal.

Abstract: The present invention is designed such that it is possible to optimize the effect of improving the efficiency of use of radio resources even when the number of user terminals to be multiplexed over the same radio resources is further increased. A user terminal performs downlink communication with a radio base station using a PDCCH resource region and a PDSCH resource region. The user terminal detects the starting position of the radio resources where the PDSCH and the PDCCH are frequency-division-multiplexed in the PDSCH resource region in the time direction, and receives the PDCCH that is frequency-division-multiplexed over the radio resources starting from the detected starting position.

Abstract: To provide a radio base station apparatus that enables the effect of improving usage efficiency of radio resources to be exerted sufficiently also in the case where the number of user terminals multiplexed into the same radio resources further increases, the radio base station apparatus performs communications using a first resource region for a downlink control channel subjected to time division, and a second resource region for a downlink data channel, and is characterized by being provided with generation sections (307, 308) that generate a first notification signal for notifying of the number of OFDM symbols of the first resource region, and a second notification signal for notifying of a starting position in the time domain of a third resource region obtained by performing frequency division on a part of the second resource region, and a multiplexing section (312) that multiplexes the first notification signal into the first resource region, and the second notification signal into the third resource regi

Abstract: The present invention is designated to improve received quality in a mobile terminal apparatus when coordinated multiple-point transmission (CoMP)—in particular, DCS-CoMP—is adopted. With the radio communication method of the present invention, when dynamic cell selection-type coordinated multiple-point transmission is adopted, a radio base station apparatus increases transmission power in radio resources to transmit to a mobile terminal apparatus, transmits the increased transmission power to the mobile terminal apparatus as transmission power information and performs dynamic cell selection-type coordinated multiple-point transmission at the increased transmission power.

Abstract: The present invention is designed to provide a base station apparatus, a mobile terminal apparatus, a communication system and a communication method that cope with the shortage of downlink control channel capacity. For a mobile terminal apparatus that receives downlink signals using a resource region for downlink control signals and a resource region for downlink data signals, a base station apparatus is configured to set a plurality of virtual to resources for downlink control signals in a plurality of physical resources that are arranged in a frequency direction in the resource region for downlink data signals, and allocate the downlink control signals, in a distributed manner, between virtual resources of a relatively low frequency band side and virtual resources of a relatively high frequency band side in a plurality of virtual resources.

Abstract: In a closed-loop TPC for a channel using a wireless resource, to which frequency hopping is applied, a high quality reception is achieved for all RBs without applying another technique to each RB. This transmission power control method, in a mobile communications system that transmits signals by frequency hopping in a plurality of resource blocks, includes a transmission power control method that transmission-power controls a channel in a closed loop using a wireless resource to which frequency hopping is applied, measures a reception channel quality of received signals for each resource block (RB1 and RB2), and transmits a TPC command-bit via a downlink so that the reception quality that is independently measured at each resource block among the resource blocks is made equal to a target reception quality.

Abstract: A disclosed OFDM-based transmission device includes a unicast channel generating unit configured to generate a unicast channel; an MBMS channel generating unit configured to generate an MBMS channel; a multiplexing unit configured to time-division-multiplex the unicast channel and the MBMS channel in the same frequency band; and a transmitting unit configured to transmit time-division-multiplexed transmission symbols. In the disclosed transmission device, the guard interval length for the MBMS channel is set longer than the guard interval length for the unicast channel.

Abstract: Provided are a receiver, a transmitter and a radio communication method capable of using non-orthogonal multiple access while suppressing cost increase and processing delay. A mobile station 200A receives non-orthogonal signals, also receives a reference signal to be used for interference cancellation, and extracts the non-orthogonal signal addressed to the mobile station 200A from the received non-orthogonal signals by demodulating and cancelling the radio signal addressed to another mobile station. In addition, the mobile station 200A demodulates the extracted non-orthogonal signal addressed to the mobile station 200A on the basis of the reference signal. The reference signal is multiplexed in the same radio resource block as a resource block allocated to the non-orthogonal signals, and is multiplexed in the radio resource block only when at least one signal is scheduled in the radio resource block.

Abstract: A base station communicating with a user device using multiple antennas in a system where a subframe is composed of multiple slots each composed of multiple basic time units is disclosed. The base station includes a first mapping unit configured to map one or more reference signals used for demodulation of one or more L1/L2 control channels and one or more data channels to be transmitted from one or more of the antennas within a predetermined number of basic time units from the beginning of each subframe; and a second mapping unit configured to map reference signals used for demodulation of data channels to be transmitted from other ones of the antennas to one or more basic time units following the basic time units to which the reference signals used for demodulation of the L1/L2 control channels and the data channels are mapped.

Abstract: A base station for communicating with a first user equipment terminal within a first system band and communicating with a second user equipment terminal within a second system band includes a first reference signal sequence generating unit configured to generate M types of reference signal sequences; a second reference signal sequence generating unit configured to generate N (N>M) types of reference signal sequences; a scheduling unit configured to allocate resource blocks to the first user equipment terminal and the second user equipment terminal; a signal multiplexing unit configured to multiplex the M types of reference signal sequences into the resource block for the first user equipment terminal and multiplex the N types of reference signal sequences into the resource block for the second user equipment terminal; and a transmitting unit configured to transmit signals including the M types of reference signal sequences and the N types of reference signal sequences.

Abstract: Provided are a receiver, a transmitter and a radio communication method capable of using non-orthogonal multiple access while suppressing cost increase and processing delay. A mobile station 200A includes a target user control signal detector 230 and an interfering user control signal detector 240 which are configured to receive a control signal to be used to cancel a non-orthogonal signal by interference canceller. The control signal includes control information containing a radio resource block allocated to the non-orthogonal signal addressed to another mobile station. The mobile station 200A demodulates and cancels the radio signal addressed to the other mobile station on the basis of the control signal.

Abstract: Provided are a receiver, a transmitter and a radio communication method capable of using non-orthogonal multiple access while suppressing cost increase and processing delay. A mobile station 200A includes a physical channel segmentation unit 210 and data demodulating/decoding units 220. A radio resource block allocated to non-orthogonal signals is defined in a frequency domain, a time domain and a non-orthogonal multiplex domain. The non-orthogonal multiplex domain has multiple levels corresponding to the number of interference cancellations by the data demodulating/decoding units 220. Interference canceller of the mobile station 200A cancels a non-orthogonal signal whose allocated radio resource block is at a lower level than that of the mobile station 200A.

Abstract: To suppress deterioration of retransmission efficiency and retransmit a transmission signal efficiently even when the system bandwidth is extended, provided are a base station apparatus (20) which divides, in a retransmission block dividing section (21), a transmission signal into retransmission blocks according to a retransmission block table in which the number of the retransmission blocks each of which is a retransmission unit of a transmission signal is increased corresponding to the number of transmission antennas and registered, and retransmits in downlink transmission signals associated with the divided retransmission blocks, and a mobile terminal apparatus (10) which receives the transmission signals associated with the retransmission blocks from the base station apparatus (20), and combines the retransmission blocks to restore the transmission signal prior to division.

Abstract: A base station apparatus includes a communication unit configured to communicate with base stations of a plurality of adjacent cells; a management unit configured to manage frequency bands for use in the adjacent cells; and a determination unit configured to determine instruction contents according to status of use of the frequency bands. The instruction contents are reported to all or a part of the adjacent cells via the communication unit. The instruction contents specify: a type of a pilot channel transmitted by a user residing in an adjacent cell; whether pilot channels of each user are code-division multiplexed or not; and whether pilot channels of each user are frequency-division multiplexed or not, and the like.

Abstract: A disclosed communication system includes multiple mobile stations and a base station. The mobile station maps a pilot channel comprising a CAZAC code to a signal including multiple frequency components arranged at regular intervals in a given frequency band, and transmits a transmission signal including the signal according to scheduling information. The mobile station performs the mapping such that its transmission signal and transmission signals of other mobile stations using different frequency bands become orthogonal to each other on a frequency axis. The base station calculates the correlation between a received signal and a pilot channel replica, performs channel estimation, and demodulates the received signal based on the result of channel estimation. The base station generates the pilot channel replica by mapping a pilot channel comprising a CAZAC code to a signal including multiple frequency components arranged at regular intervals in a given frequency band.

Abstract: A mobile station configured to perform MIMO communication is disclosed, where the mobile station includes a control unit configured to determine a radio access scheme to be applied, based on at least one of a transmission frequency bandwidth to be used and a transmission stream number used in the MIMO communication.