Abstract: A wireless communication system includes a wireless transmission device and a wireless reception device. The wireless reception device includes: a plurality of reception antennas; and a processor connected to the reception antennas. The processor executes a process including: selecting transmission beam candidates or reception beam candidates based on a reception power of a signal transmitted by using transmission beams of a first array or of a signal received by using reception beams of the first array, the first array setting a delay difference between a plurality of antennas; and determining a beam pattern of a transmission beam and a reception beam based on a reception power of a signal transmitted by using transmission beam candidates formed by a second array or of a signal received by using reception beam candidates formed by the second array, the second array setting a phase difference between a plurality of antennas.

Abstract: A wireless communication system includes a wireless transmission device and a wireless reception device. The wireless reception device includes: a plurality of reception antennas; and a processor connected to the reception antennas. The processor executes a process including: selecting transmission beam candidates or reception beam candidates based on a reception power of a signal transmitted by using transmission beams of a first array or of a signal received by using reception beams of the first array, the first array setting a delay difference between a plurality of antennas; and determining a beam pattern of a transmission beam and a reception beam based on a reception power of a signal transmitted by using transmission beam candidates formed by a second array or of a signal received by using reception beam candidates formed by the second array, the second array setting a phase difference between a plurality of antennas.

Abstract: A transmission method includes: selecting, from a cooperative cluster covered by a plurality of transmission points that transmit signals in cooperation with each other, a transmission point positioned in vicinity of a boundary between the cooperative cluster and another cooperative cluster; generating a first transmission weight that causes the selected transmission point to form a directional beam directed in a direction different from a direction of the another cooperative cluster; generating, by using the first transmission weight generated, a second transmission weight that weights transmission signals, such that signals that are transmitted simultaneously from the transmission points and addressed to a plurality of transmission destinations are separately received; generating, by using the second transmission weight generated, streams to be transmitted from the transmission points, the streams respectively corresponding to antennas; and transmitting the streams generated, from the transmission points.

Abstract: A transmitter includes: a plurality of transmission antennas; a channel estimator configured to estimate channels between the plurality of transmission antennas and a plurality of receivers; a scheduler configured to schedule a combination of target receivers of transmitting downlink signals on same radio resource among the plurality of receivers; and a transmitter configured to transmit downlink signals intended for the combination scheduled by the scheduler by beam forming from the plurality of transmission antennas on the same radio resource. The scheduler modifies a selecting rule related to the combination of target receivers in accordance with a delay time of an opportunity of transmitting the downlink signal from a timing of estimating the channels.

Abstract: A transmission control device includes a memory and a processor connected to the memory. The processor executes a process including: selecting a reference transmission point as a starting point of generating a link from among a plurality of transmission points of which each wirelessly transmits a signal; sequentially selecting the transmission points one by one for each hierarchy corresponding to a number of hops from the selected reference transmission point and retrieving ones of the transmission points for which radio quality between the ones and the selected transmission point satisfies a predetermined criterion; and generating a link between the selected transmission point and a transmission point, among the transmission points obtained as a result at the retrieving, not connected to others of the transmission points to connect the two transmission points.

Abstract: A transmission control device includes a memory and a processor connected to the memory. The processor executes a process including: selecting a reference transmission point as a starting point of generating a link from among a plurality of transmission points of which each wirelessly transmits a signal; sequentially selecting the transmission points one by one for each hierarchy corresponding to a number of hops from the selected reference transmission point and retrieving ones of the transmission points for which radio quality between the ones and the selected transmission point satisfies a predetermined criterion; and generating a link between the selected transmission point and a transmission point, among the transmission points obtained as a result at the retrieving, not connected to others of the transmission points to connect the two transmission points.

Abstract: A method performed by a transmission device and a reception device in a wireless communication system, the method including: executing a process for receiving a reference signal, which is transmitted from each of plural transmit antennas of the transmission device, through a specific receive antenna which is one of at least one receive antenna of the reception device; executing a process for deciding a transmit antenna weight and a receive antenna weight based on the reference signal, the transmit antenna weight and the receive antenna weight being applied in a case where only the specific receive antenna receives a signal which is transmitted by each of the plural transmit antennas based on same transmission data; and executing a process for transmitting first information about the transmit antenna weight and second information about the receive antenna weight to the transmission device.

Abstract: According to one aspect, a base station that is connected to a plurality of transmission and reception points includes a calibrator. The calibrator calculates calibration coefficients to be multiplied on weights in beamforming communication at each of a plurality of transmission and reception points based on the beamforming communication at each of a plurality of transmission and reception points.

Abstract: A transmission method includes: selecting, from a cooperative cluster covered by a plurality of transmission points that transmit signals in cooperation with each other, a transmission point positioned in vicinity of a boundary between the cooperative cluster and another cooperative cluster; generating a first transmission weight that causes the selected transmission point to form a directional beam directed in a direction different from a direction of the another cooperative cluster; generating, by using the first transmission weight generated, a second transmission weight that weights transmission signals, such that signals that are transmitted simultaneously from the transmission points and addressed to a plurality of transmission destinations are separately received; generating, by using the second transmission weight generated, streams to be transmitted from the transmission points, the streams respectively corresponding to antennas; and transmitting the streams generated, from the transmission points.

Abstract: A transmission control device includes an acquiring unit that acquires propagation delay time for each propagation path between a plurality of terminal devices and a plurality of transmitter stations; a selector that selects, based on the propagation delay time acquired by the acquiring unit, combinations of terminal devices having similar propagation delay differences from the plurality of the transmitter stations; and a controller that controls transmission timing of the plurality of the transmitter stations that transmit signals to the combinations of the terminal devices selected by the selector.

Abstract: In a multi-carrier cellular system, a second synchronization code (a Walsh code or a GCL series code) mapped on a second synchronization channel is used as a signal for specifying in which cell of the base station a mobile station terminal device itself is. A signal transmitted from the base station to the mobile station terminal device is mapped in a radio frame having two-dimensional extension in frequency and time directions. When mapping a certain series number of the second code for specifying a cell or a cell group on the radio frame as the second synchronization channel, phase rotation or circular shift in which one radio frame is one cycle is applied to the second synchronization code. On the receiving side, the head timing of the radio frame is known by knowing the phase rotation angle or the amount of circular shift of the second synchronization code.

Abstract: A transmitter includes: a plurality of transmission antennas; a channel estimator configured to estimate channels between the plurality of transmission antennas and a plurality of receivers; a scheduler configured to schedule a combination of target receivers of transmitting downlink signals on same radio resource among the plurality of receivers; and a transmitter configured to transmit downlink signals intended for the combination scheduled by the scheduler by beam forming from the plurality of transmission antennas on the same radio resource. The scheduler modifies a selecting rule related to the combination of target receivers in accordance with a delay time of an opportunity of transmitting the downlink signal from a timing of estimating the channels.

Abstract: A method performed by a transmission device and a reception device in a wireless communication system, the method including: executing a process for receiving a reference signal, which is transmitted from each of plural transmit antennas of the transmission device, through a specific receive antenna which is one of at least one receive antenna of the reception device; executing a process for deciding a transmit antenna weight and a receive antenna weight based on the reference signal, the transmit antenna weight and the receive antenna weight being applied in a case where only the specific receive antenna receives a signal which is transmitted by each of the plural transmit antennas based on same transmission data; and executing a process for transmitting first information about the transmit antenna weight and second information about the receive antenna weight to the transmission device.

Abstract: A wireless communication method used by a wireless communication apparatus is disclosed. The wireless communication method transmits and receives control information divided into a second control information containing information related to the demodulation and decoding of traffic channel and a first control information containing information related to the MIMO separation of the second control information.

Abstract: A transmission control device includes a memory and a processor connected to the memory. The processor executes a process including: selecting a reference transmission point as a starting point of generating a link from among a plurality of transmission points of which each wirelessly transmits a signal; sequentially selecting the transmission points one by one for each hierarchy corresponding to a number of hops from the selected reference transmission point and retrieving ones of the transmission points for which radio quality between the ones and the selected transmission point satisfies a predetermined criterion; and generating a link between the selected transmission point and a transmission point, among the transmission points obtained as a result at the retrieving, not connected to others of the transmission points to connect the two transmission points.

Abstract: A wireless communication method used by a wireless communication apparatus is disclosed. The wireless communication method transmits and receives control information divided into a second control information containing information related to the demodulation and decoding of traffic channel and a first control information containing information related to the MIMO separation of the second control information.

Abstract: A transmission control device includes an acquiring unit that acquires propagation delay time for each propagation path between a plurality of terminal devices and a plurality of transmitter stations; a selector that selects, based on the propagation delay time acquired by the acquiring unit, combinations of terminal devices having similar propagation delay differences from the plurality of the transmitter stations; and a controller that controls transmission timing of the plurality of the transmitter stations that transmit signals to the combinations of the terminal devices selected by the selector.

Abstract: The base station may selectively apply one of a first time period having a first guard period (GP) and a second time period having a second GP to time-division duplex communication with a terminal. Further, the base station may notify the terminal of information related to a timing of selectively applying one of the first time period and the second time period, and transmit a predetermined signal in the first guard period.

Abstract: According to one aspect, a base station that is connected to a plurality of transmission and reception points includes a calibrator. The calibrator calculates calibration coefficients to be multiplied on weights in beamforming communication at each of a plurality of transmission and reception points based on the beamforming communication at each of a plurality of transmission and reception points.

Abstract: A radio communication apparatus including: an antenna configured to receive a frame including reference signals and including other signals corresponding to radio resources to which channels are mapped, and a processor configured to acquire degree of usage of the radio resource, to calculate a reception quality of the reference signals, and to adjust the reception quality in accordance with the degree.