Abstract: A first problem is to reduce an enormous uplink throughput of a base station that feedback information needs so as to improve an uplink throughput of useful user data. A second problem is to carry out a frequency segment assignment to guarantee a number of communication times and a communication quality to every terminal apparatus so as to increase a downlink throughput. The second problem is solved together. As means to give the number of communication times per each terminal apparatus, means to estimate an expected value of the number of communication times per each terminal apparatus, and means to assign the terminal apparatus per each frequency segment are arranged in the base station apparatus.

Abstract: A radio communications system includes, in base stations, or nodes nearer to a core network than the base stations, a terminal distribution checking unit, a unit of determining whether to execute intercell interference reduction based on the result of the checking, a coordination unit which executes intercell interference reduction between base stations in corporation with each other.

Abstract: A wireless communication system includes an asynchronized base station apparatus to perform an operation that is equivalent to the synchronization with a synchronized base station apparatus having received a sync pulse. The system includes a synchronized base station that uses a received sync pulse to synchronize itself with a base station which is a different cell, an asynchronized base station located in the cell of the synchronized base station, and a terminal. The asynchronized base station includes a unit that determines a reception timing difference, at the terminal, between a transport signal transmitted by the synchronized base station and a transport signal transmitted by the asynchronized base station, and a unit that controls the transmission timing of the asynchronized base station such that the reception timing difference becomes equal to or less than a predetermined value.

Abstract: To provide a wireless base station comprising an array antenna which transmits packets to terminals, a packet scheduler which determines transmission sequence of the packets, a modulator which generates modulated signals based on the packets, and a beam former for transmission signal which multiplies the packets with array weights for transmission signal and outputs the transmission signal to the array antenna the beam former for transmission signal comprises a memory which stores the array weights for transmission signal associated with the terminals' IDs. The beam former for transmission signal receives the IDs of selected terminals from the packet scheduler, refers to the memory, and selects the array weights for transmission signal by the IDs of the terminals.

Abstract: To reduce power consumption of a mobile station, this invention provides a wireless communication method for communicating between a base station and a plurality of terminals using a plurality of channels, the channels being slots obtained by dividing frequency-divided carriers by time, in which the base station allocates a set of the channels which is composed of a plurality of neighboring carriers and/or a plurality of successive slots for the each terminal, and the base station allocates at least one of the channels included in the channel sets for packet transmission the terminals.

Abstract: Wireless communication arrangements including: first base station referring to beam scheduling information including identification information of a beam pattern to be used in each slot by the second base station, selecting, where identification information of the beam area to be used by the second base station in the slot assigned is coincident with the identification information of the first interference beam area received from the wireless terminal, the first data rate received from the wireless terminal, and selects, where the identification information of the beam area to be used by the second base station is not coincident with the identification information of the first interference beam area, the second data rate received from the wireless terminal; a step at which the first base station modulates data in accordance with one of the selected first data rate and second data rate, and transmits modulated data to the wireless terminal.

Abstract: Wireless communication arrangements including: performing scheduling of transmitting signal to each of the mobile stations so that interference of radio waves sent from each of the remote units to each of the mobile stations can be suppressed based on priority level of the mobile station and the interference area information; generating information to control the direction-variable antenna of each of the plurality of remote units, so that the corresponding remote unit forms beam according to scheduling result; and transmitting the information to control the direction-variable antenna to the plurality of remote units.

Abstract: Provided is a radio communication system including a plurality of base stations and a repeater apparatus, in which the repeater apparatus amplifies and transmits a radio signal received from at least one of the plurality of base stations, and controls a domain in which the radio signal is transmitted based on a traffic amount of each of the plurality of base stations. Accordingly, the number of installed base stations which are costly is reduced, and an operating rate of the respective base stations is gained along with the decrease in number of installed base stations.

Abstract: A wireless communication which suppresses radio interference between wireless base stations and improves the channel efficiency is implemented. In the wireless communication system including a central base station, a plurality of remote base stations having a direction-variable antenna, and a plurality of mobile stations to communicate with the remote base stations, the central base station performs centralized management of radio-wave beam patterns to be sent to the plurality of mobile stations which will communicate with remote base stations and performs packet scheduling of the mobile stations in such a manner that radio waves sent from the remote base stations will not cause strong interference at the mobile stations.

Abstract: Provided is a wireless base station comprising: a power control unit, a reference information acquisition unit and a reference information storing unit, wherein the wireless base station comprises a first control signal receiving unit for receiving a first uplink control signal used by a mobile station connected to the wireless base station and for requesting the power control unit to control the transmission, and a second control signal receiving unit for receiving a second uplink control signal used by a mobile station connected to the neighbor base station and for requesting the power control unit to control the transmission power, and wherein the power control unit controls the transmission power of the downlink signal based on the request to control the transmission power from the first control signal receiving unit and the request to control the transmission power from the second control signal receiving unit.

Abstract: A terminal 211 measures pilot signals transmitted in directional (beam) patterns from an adjacent cell and an own cell, and estimates reception qualities with the presence (high)/absence (low) of the interference from the adjacent cell. The terminal 211 requests data rate request values (DRC1, DRC2) corresponding to the reception qualities with the presence/absence of the interference to the base station 201. The base station 201 shares beam direction schedule with an adjacent cell base station, and confirms the presence/absence of interference to the terminal 211 for each slot. In accordance with the presence/absence of the interference, the base station 201 selects a suitable one of the two values of the data rates requested from the terminal 211, and modulates the data and transmits it.

Abstract: This invention provides a controller of multiplex number in spatial domain that collects from a plurality of radio communication apparatuses the number of terminals connected thereto and the multiplex number in spatial domain, determines the ratio of (the number of terminals connected thereto)/(the multiplex number in spatial domain) for each radio communication apparatus, and adjusts the multiplex number for each radio communication apparatus so that the above ratio will be equal between or among the radio communication apparatuses. The radio communication apparatuses transmit the number of terminals connected thereto and the multiplex number in spatial domain to the controller of multiplex number in spatial domain.

Abstract: A wireless communication system comprises radio base station apparatuses each of which transmits an estimation pilot in advance for estimating the quality of a downlink communication after a spatial signal processing performed after a time unified among the radio base station apparatuses; and radio terminal apparatuses each of which receives the estimation pilot to determine the quality of the downlink communication, thereby reporting the determined downlink communication quality to the radio base station apparatus via an uplink channel. The estimation pilot is transmitted at the same time and frequency established among the radio base station apparatuses by use of the same directivity beam as used for transmitting the data after the unified time.

Abstract: A base station apparatus is provided for adaptively controlling a maximal accommodation channel number per unit area (for example, the coverage area of a cell or sector) in accordance with a traffic quantity without relying upon detachment of a mobile base station and installation of a repeater. Upon inputting of a plurality of baseband signals of a user channel-multiplexed channel group, linear coupling is performed by a weight which is different per area that outputs it, thereby enabling control of the channel density. Additionally, a per-group available channel number is constantly monitored to control the weight while using threshold judgment for the available channel number as a trigger, thus achieving situation-sensitive prompt handleability.

Abstract: When a receiving apparatus which employs a OFDM-based cellular wireless communication scheme detects as an excessive signal for each frame, the signal having signal intensity exceeding a reference value after a Fourier transform, a gain variable according to an excessive quantity relative to the reference value is used for each frame to control signal intensity such that the amplitude thereof is at most the reference value.

Abstract: A signal transmission and reception method, and a base station and a mobile terminal therefor are disclosed. In a communication system including a base station and at least a mobile terminal, the transmission of the data signal from the base station to each mobile terminal is controlled in accordance with the manner in which the pilot signal transmitted from the base station to each mobile terminal is received by the mobile terminal. In the signal transmission method, the proper one of a plurality of signal multiplexing schemes is selected based on the control signal received from each mobile terminal, and the transmission signal is multiplexed by the selected signal multiplexing scheme and transmitted to each mobile terminal. The transmission signal includes the data signal and the dedicated pilot signal transmitted to the mobile terminal.

Abstract: A radio communication apparatus enhances cell throughput by adaptive selection of spatially multiplexed channels in consideration of interferences in a local cell and reducing load for calculation of array weights by storing them in advance as fixed values and outputting fixed beams. To reduce the calculation load for the adaptive selection of spatially multiplexed channels that takes interferences within the local cell into consideration, the radio communication apparatus adopts a packet scheduling method that selects a combination of fixed beams and determines the number of spatially multiplexed channels, based on the fixed beams for mobile apparatuses with packets waiting to be transmitted and pre-calculated correlative quantities of inter-beam interferences between these fixed beams.

Abstract: A terminal 211 measures pilot signals transmitted in directional (beam) patterns from an adjacent cell and an own cell, and estimates reception qualities with the presence (high)/absence (low) of the interference from the adjacent cell. The terminal 211 requests data rate request values (DRC1, DRC2) corresponding to the reception qualities with the presence/absence of the interference to the base station 201. The base station 201 shares beam direction schedule with an adjacent cell base station, and confirms the presence/absence of interference to the terminal 211 for each slot. In accordance with the presence/absence of the interference, the base station 201 selects a suitable one of the two values of the data rates requested from the terminal 211, and modulates the data and transmits it.

Abstract: An antenna pattern assigning method capable of avoiding interference between a plurality of base transmission stations constituting a radio system in a cellular type broad band communication. In the radio system, when assigning a fixed beam pattern different for each frequency, each of the radio base transmission station devices transmits a radio wave having a directivity pattern having a peak in the same direction in two or more different frequencies, and between adjacent radio base transmission station devices, radio transmission is performed by using different directivity patterns in the two or more frequencies.

Abstract: Data transmission is performed using the most suitable data rate for the radiation pattern of an antenna. Using an individual pilot channel of a first slot, a base station transmits a pilot signal in a specified direction with a beam pattern having narrow directivity. A wireless terminal located in that direction receives the pilot signal and determines a data rate according to the reception quality of the pilot signal. The wireless terminal transmits to the base station a signal requesting the determined data rate. The base station receives that signal and, based on the requested data rate, transmits data to the wireless terminal with a beam pattern in the same direction as the direction in which the pilot signal was transmitted, using a data channel of a second slot, which occurs a predetermined number of slots after the first slot.