Patent application number | Description | Published |
20090280760 | RADIO COMMUNICATION APPARATUS AND RADIO COMMUNICATION METHOD - A disclosed radio communication apparatus transmits a radio signal to multiple users via multiple transmit antenna groups at appropriate transmit power levels, each of the transmit antenna groups including one or more transmit antennas, the transmit antenna groups having respective transmit power constraints. The apparatus includes a precoding unit configured to perform precoding on signals modulated for individual users and generate transmit weights, an optimum transmit power calculation unit configured to receive the transmit weights from the precoding unit and use components of the transmit weights and respective transmit power limit values for the transmit antenna groups to calculate an initial value for a transmit power optimization problem for calculation of the appropriate transmit power levels for the users, and a transmission unit configured to transmit radio signals at the calculated transmit power levels. | 11-12-2009 |
20090280855 | RADIO COMMUNICATION APPARATUS AND RADIO COMMUNICATION METHOD - A disclosed radio communication apparatus includes a preceding unit configured to precode multiple streams, a splitting unit configured to split the precoded streams into two or more stream sets each including one or more streams, a sub power optimization unit configured to execute an iterative transmit power optimization algorithm on each of the split stream sets to determine respective transmit power levels for the individual stream sets, a power optimization unit configured to execute the iterative transmit power optimization algorithm by using the determined transmit power levels as initial values for the iterative transmit power optimization algorithm to determine respective transmit power levels for the individual streams, and a transmission unit configured to transmit radio signals from individual transmit antennas at the determined transmit power levels. | 11-12-2009 |
20090280856 | RADIO COMMUNICATION APPARATUS AND RADIO COMMUNICATION METHOD - A disclosed radio communication apparatus includes a preceding unit, a optimum transmit power calculation unit and a transmission unit. The optimum transmit power calculation unit receives the transmit weight related information from the preceding unit and calculates a transmit power level to optimize an objective function in accordance with an interior point method. The objective function results from addition of a barrier function adjusted with a barrier parameter to an original objective function associated with a constrained optimization problem. The original objective function includes a function of respective channel capacities for individual users derived from the transmit weight related information. The optimum transmit power calculation unit adaptively updates a logarithm of the barrier parameter and uses a gradient obtained through a high-order derivative with the logarithm of the barrier parameter to calculate the transmit power level to optimize the resulting objective function. | 11-12-2009 |
20100272211 | RADIO COMMUNICATION APPARATUS AND METHOD - A disclosed radio communication method includes precoding modulated information signal sequences to calculate transmit weight information, setting initial transmit power based on prior information including the calculated transmit weight information, generating an objective function of a user channel capacity for a constrained optimization problem based on the transmit weight information and the initial transmit power, generating a new objective function by adding a barrier function to the objective function, using an initial temporary barrier parameter to initiate iteration of an optimization operation for the new objective function, setting an initial barrier parameter based on comparison between the current and previous outputs, calculating transmit power to optimize the new objective function in accordance with an interior point method based on the initial transmit power and the initial barrier parameter and allocating the calculated transmit power to the respective transmit antennas. | 10-28-2010 |
20130322362 | Communication System, Transmitting Device, Receiving Device, and Communication Method - There is provided a communication system capable of achieving a high usage efficiency of frequencies without the need for cooperation of multiplexed users. A communication system communicates over frequency channels set by dividing a frequency bandwidth assigned to the system allows interference between channels by overlapping the adjacent frequency channels with each other in the frequency domain, or a transmitting and receiving device, which transmits and receives a signal by allowing the interference between symbols at a waveform level for each channel to decrease the occupied bandwidth, is provided with ICI removal and ISI compensation filter | 12-05-2013 |
Patent application number | Description | Published |
20100104042 | COMMUNICATION SYSTEM, TRANSMISSION DEVICE, RECEPTION DEVICE, AND COMMUNICATION METHOD - There is provided a communication system capable of achieving a high usage efficiency of frequencies without the need for cooperation of multiplexed users. A communication system communicates over frequency channels set by dividing a frequency bandwidth assigned to the system allows interference between channels by overlapping the adjacent frequency channels with each other in the frequency domain, or a transmitting and receiving device, which transmits and receives a signal by allowing the interference between symbols at a waveform level for each channel to decrease the occupied bandwidth, is provided with ICI removal and ISI compensation filter | 04-29-2010 |
20110080884 | COORDINATED TRANSMISSION METHOD, COORDINATED TRANSMISSION SYSTEM, CENTRAL STATION AND RADIO BASE STATION - A coordinated transmission method of the invention has the steps of selecting a directional pattern corresponding to an area in which a radio terminal locates, from among a plurality of directional patterns determined respectively corresponding to a plurality of resources in frequency domains where the plurality of directional patterns is configured so that a plurality of radio base stations surrounding the area transmits, to the area, directional beams of same frequency domain resources to face one another, while not transmitting the directional beams of the same frequency domain resources using the same frequency domain resources to areas adjacent to the area, and of distributing a signal to transmit to the radio terminal according to the selected directional pattern, determining a frequency domain and directions of directional beams regarding the distributed signal, and delivering the signal to each of the plurality of radio base stations that simultaneously transmits the signal to the radio terminal. | 04-07-2011 |
20110188540 | RADIO COMMUNICATION SYSTEM, RADIO BASE STATION APPARATUS AND COMMUNICATION CONTROL METHOD - The present invention provides a radio communication system which includes a plurality of radio base station apparatuses that transmit reference signals orthogonal to each other among a plurality of transmitting antennas and a mobile terminal apparatus that performs channel estimation based on the reference signals transmitted from the plurality of radio base station apparatuses, sets priority among a plurality of neighboring radio base station apparatuses and introduces a bias in the number of reference signals that can be allocated to each radio base station apparatus according to the priority from the radio resources shared among the plurality of neighboring radio base station apparatuses. | 08-04-2011 |
20120026955 | RADIO COMMUNICATION APPARATUS AND RADIO COMMUNICATION METHOD - A radio communication apparatus and radio communication method are provided which coordinates a plurality of radio base station apparatuses in consideration of interference cancelling capability of mobile terminal apparatuses, and can thereby improve the throughput of the entire system even when the amount of information shared among a plurality of radio base station apparatuses is small. Ina system that performs multicell coordinated transmission in downlink, a radio communication method according to the present invention selects a set of mobile terminal apparatuses whose interference can be cancelled from a plurality of mobile terminal apparatus, when a plurality of radio base station apparatuses perform joint scheduling, using interference cancelling capability information fed back from each mobile terminal apparatus; then performs joint scheduling for the set of selected mobile terminal apparatuses. | 02-02-2012 |
20120026956 | RADIO COMMUNICATION SYSTEM, CENTRALIZED STATION, CONTROL STATION APPARATUS, RADIO BASE STATION AND COORDINATED TRANSMISSION METHOD - The radio communication system of the present invention is provided with a cluster pattern determining section | 02-02-2012 |
Patent application number | Description | Published |
20130252625 | BASE STATION APPARATUS, MOBILE TERMINAL APPARATUS AND SCHEDULING METHOD - To provide a base station apparatus, mobile terminal apparatus and scheduling method for enabling fairness of user throughput to be improved, a scheduling method is characterized by having the steps of notifying a mobile terminal apparatus of allocation information of radio resources to each cluster pattern with a plurality of cluster patterns comprised of clusters formed of a plurality of adjacent sectors predefined and with different radio resources allocated for each of the cluster patterns, receiving channel information•channel quality information corresponding to each of the cluster patterns for each of the radio resources from the mobile terminal apparatus, and controlling allocation of the radio resources to the mobile terminal apparatus, based on the channel information•channel quality information, where at least one of the cluster patterns is a coordinated cluster pattern to perform coordinated transmission between adjacent sectors in a cluster. | 09-26-2013 |
20140003272 | MOBILE TERMINAL APPARATUS, RADIO BASE STATION APPARATUS AND RADIO COMMUNICATION METHOD | 01-02-2014 |
20140293950 | RADIO BASE STATION AND RADIO COMMUNICATION METHOD - To provide a radio communication method when a macro-base station and micro-base station are regarded as a plurality of transmission points and the plurality of transmission points performs downlink communications using a plurality of carriers, in the radio communication method of the invention, a macro-base station ( | 10-02-2014 |
20140301340 | RADIO COMMUNICATION SYSTEM, BASE STATION APPARATUS, MOBILE TERMINAL APPARATUS, AND INTERFERENCE MEASUREMENT METHOD - The present invention is designed to measure interference with high accuracy, without changing the density of CSI-RSs, in a future system that does not reply on CRSs. A base station apparatus ( | 10-09-2014 |
20140307576 | RADIO COMMUNICATION SYSTEM, BASE STATION APPARATUS, MOBILE TERMINAL APPARATUS AND INTERFERENCE MEASUREMENT METHOD - To increase the number of CSI-RSs for interference measurement to improve interference measurement accuracy, a first reference signal for channel state measurement and a second reference signal for interference measurement are assigned to reference signal resources defined for transmission of the first reference signal, and a mobile terminal apparatus that supports both the first reference signal and the second reference signal is notified of pattern information to identify an assignment pattern of the first reference signal and the second reference signal. A second mobile terminal apparatus that supports the first reference signal and that does not support the second reference signal is notified of pattern information to identify an assignment pattern of the first reference signal, and of assignment information indicating that resources assigned the second reference signal are assigned a third reference signal of zero power for channel state measurement. | 10-16-2014 |
20140307577 | RADIO COMMUNICATION SYSTEM, INTERFERENCE MEASUREMENT METHOD, RADIO BASE STATION APPARATUS, AND USER TERMINAL - The present invention is designed to provide a radio communication system, an interference measurement method, a radio base station apparatus, and a user terminal whereby highly accurate interference measurement is possible. A radio communication system according to the present invention includes a user terminal and a radio base station apparatus that is connected to the user terminal, and, in this radio communication system: the radio base station apparatus has: a determining section that determines a subband pattern for interference measurement; and a transmission section that transmits a reporting signal to indicate the determined subband pattern to the user terminal; and the user terminal has: a receiving section that receives the reporting signal and acquires the subband pattern; and | 10-16-2014 |
20150045085 | RADIO COMMUNICATION METHOD, LOCAL AREA BASE STATION APPARATUS, MOBILE TERMINAL APPARATUS AND RADIO COMMUNICATION SYSTEM - A method for making the uplink and downlink coverages in a local area symmetrical by executing transmission power control in the downlink of a local area in HetNet is disclosed. A radio communication method is provided in which a local area base station apparatus, arranged in a wide area where a first carrier frequency is used and forming a local area that is narrower than the wide area, transmits a downlink signal, using a second carrier frequency, which belongs to a different frequency band from the first carrier frequency and which has a wider bandwidth than the first carrier frequency, the local area base station apparatus transmits a detection signal that is used to detect the local area base station apparatus in the mobile terminal apparatus, and the local area base station apparatus transmits the downlink signal for the mobile terminal apparatus with transmission power that is determined. | 02-12-2015 |
20150078281 | COMMUNICATION SYSTEM, MOBILE TERMINAL APPARATUS, LOCAL AREA BASE STATION AND COMMUNICATION METHOD - The present invention is designed to provide highly efficient local area radio access. A communication system, in which a mobile terminal apparatus ( | 03-19-2015 |
20150085838 | RADIO COMMUNICATION METHOD, RADIO BASE STATION AND RADIO COMMUNICATION SYSTEM - A radio communication method is provided in which beam forming information for forming transmission beams directed from the small base station to the user terminal are generated based on position-related information of the user terminal acquired by communication between the macro base station and the user terminal using a coverage carrier and position-related information of the small base station, and the small base station precodes at least one of a common control signal and a reference signal that are common in a small cell (C2) based on the beam forming information and transmits the precoded signal from a plurality of transmitting antennas using a capacity carrier. | 03-26-2015 |
20150117561 | CODEBOOK ADAPTATION METHOD, RADIO BASE STATION APPARATUS AND USER EQUIPMENT - A method and system for adapting the structure of a codebook for precoding, by changing parameters, in downlink MIMO transmission using a plurality of transmitting antennas, is disclosed. A codebook adaptation method to adapt a codebook for precoding applied to downlink MIMO transmission includes the steps of reporting the codebook size of the codebook, defined with a plurality of parameters pertaining to gain information and phase information, from one communication apparatus to another communication apparatus, and, at the other communication apparatus, adapting the structure of the codebook, based on the codebook size reported from the one communication apparatus. | 04-30-2015 |
20150119027 | COMMUNICATION SYSTEM, MOBILE TERMINAL APPARATUS, LOCAL AREA BASE STATION APPARATUS AND COMMUNICATION METHOD - The present invention is designed to provide highly efficient local area radio access. In a communication system in which a mobile terminal apparatus ( | 04-30-2015 |
20150334639 | COMMUNICATION SYSTEM, MOBILE TERMINAL APPARATUS, LOCAL AREA BASE STATION APPARATUS AND COMMUNICATION METHOD - The present invention is designed to provide highly efficient local area radio access. A communication system, in which a mobile terminal apparatus ( | 11-19-2015 |
20150349866 | RADIO BASE STATION, USER TERMINAL, RADIO COMMUNICATION METHOD AND RADIO COMMUNICATION SYSTEM - The present invention is designed to provide a radio base station, a user terminal, a radio communication method and a radio communication system of novel structures that can achieve improved throughput and system capacity. A radio base station transmits downlink reference signals that are specific to a plurality of transmission beams, a plurality of user terminals feed back channel state information acquired by channel estimation using the downlink reference signals, to the radio base station, the radio base station determines a plurality of user terminals to non-orthogonal-multiplex, per transmission beam, based on the channel state information that is fed back, and non-orthogonal-multiplexes downlink signals for the plurality of user terminals that are determined, in each of the plurality of transmission beams, and a plurality of user terminals that are determined, after having canceled interference between the transmission beams by means of a linear filter, demodulates downlink signals for the subject terminal, from the downlink signals that are non-orthogonal-multiplexed in each transmission beam. | 12-03-2015 |
20150358064 | RADIO BASE STATION, USER TERMINAL, RADIO COMMUNICATION METHOD AND RADIO COMMUNICATION SYSTEM - The present invention is designed to provide a radio base station, a user terminal, a radio communication method and a radio communication system of novel structures that can achieve improved throughput and system capacity. A radio base station transmits downlink reference signals that are specific to a plurality of transmission beams, a plurality of user terminals feed back coarse channel state information that is acquired by channel estimation, to the radio base station, the radio base station selects a plurality of user terminals to make feed back accurate channel state information based on the coarse channel state information, a plurality of user terminals that are selected feed back accurate channel state information, the radio base station determines a plurality of user terminals to non-orthogonal-multiplex, per transmission beam, based on the accurate channel state information, and non-orthogonal-multiplexes downlink signals, and a plurality of user terminals that are determined, after having canceled interference between the transmission beams by means of a linear filter, cancels downlink signals for other terminals, from the downlink signals that are non-orthogonal-multiplexed in each transmission beam. | 12-10-2015 |
20150373601 | RADIO BASE STATION, USER TERMINAL, CELL SELECTION METHOD AND RADIO COMMUNICATION SYSTEM - A system in which user terminal is able to aggressively select small cells in a radio communication system in which a macro cell and small cells are arranged to overlap each other is disclosed. A macro base station (M) configured to form a macro cell carries out the steps of determining the offset value to use in cell selection in a user terminal (UE) based on transmission property information of a second carrier in the small cell, and reporting the offset value to the user terminal (UE). Also, the user terminal (UE) carries out the steps of measuring the received quality of reference signals from the macro base station (M) and the small base station (S), receiving the offset value that is reported from the macro base station (M), and carrying out cell selection based on the received quality that is measured and the offset value that is received. | 12-24-2015 |
20150382327 | USER TERMINAL, RADIO BASE STATION AND RADIO COMMUNICATION METHOD - The present invention is designed to provide a user terminal, a radio base station and a radio communication method of novel structures that can achieve a good communication environment. A radio base station non-orthogonal-multiplexes downlink signals for a plurality of user terminals over a given radio resource, a user terminal having received the downlink signals for the plurality of user terminals decodes downlink signal for another user terminal, judges whether or not the downlink signal for the other user terminal has been successfully received, based on the decoding result of the downlink signal, reports a judgement result as to whether or not the downlink signal for the other user terminal has been successfully received and a judgement result as to whether or not a downlink signal for the user terminal has been successfully received, to the radio base station, and then the radio base station executes retransmission control of downlink signals based on reports from the user terminal. | 12-31-2015 |
20160029350 | RADIO BASE STATION, USER TERMINAL AND RADIO COMMUNICATION METHOD - The present invention is designed to improve spectral efficiency in a radio communication system which can use non-orthogonal multiple access (NOMA). Steps are provided in which a radio base station configures one of a plurality of transmission mode including a first transmission mode, which groups a plurality of transmission methods including a transmission method to employ non-orthogonal multiple access (NOMA) and multiple-user multiple-input and multiple-output (MU-MIMO), and a second transmission mode, which groups a plurality of transmission methods including a transmission method to employ this NOMA and open-loop transmit diversity, and transmits a downlink signal for this user terminal based on the configured transmission mode. | 01-28-2016 |
20160037460 | RADIO BASE STATION, USER TERMINAL AND RADIO COMMUNICATION METHOD - The present invention is designed to make possible link adaptation that is suitable for future radio communication systems. A radio base station according to the present invention has a coding section that encodes downlink data for each of a plurality of user terminals, a modulation section that modulates the downlink data for each of the plurality of user terminals, and a transmission section that multiplexes the downlink data for each of the plurality of user terminals on a per subband basis, and transmits the downlink data for each of the plurality of user terminals by using transmission power that is allocated to each of the plurality of user terminals on a per subband basis. | 02-04-2016 |