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: In a wireless base station comprising a center unit, and a remote unit provided with an array antenna and connected to the center unit through an optical fiber, the center unit outputs to the optical fiber a transmission signal in a base band state prior to array processing, the remote unit performs the array processing of transmission signals in accordance with array weights and converts the transmission signals into RF signals, thereby to localize the compensation for transmission signal deviations occurring among the antenna elements on the remote unit side.

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.

Abstract: A wireless data-communication arrangements including a wireless terminal, located in a direction, receiving the pilot signal and determining a data rate according to reception quality of the pilot signal; the wireless terminal transmitting to a base station a signal for requesting the determined data rate; the base station receiving the signal and, based on the requested data rate, transmitting data to the wireless terminal with the radiation pattern, which includes the beam pattern in a same direction as the direction in which the pilot signal was transmitted, using a data channel of a second slot which is a predetermined number of slots after the first slot.

Abstract: A wireless communication method in which a base station and a wireless terminal communicate, including: an operation at which a first and a second base station transmit, for each beam area, a pilot signal including identification information to identify the base station and the beam area, in a beam pattern; an operation at which the wireless terminal obtains received power of each pilot signal; an operation at which the wireless terminal causes one of the beam areas of the first base station to be a desired wave beam area, and determines two data rates for requiring to the base station: one of the data rates being a first data rate used in a case that interference from the second base station is relatively high and another of the data rates being a second data rate used in a case that the interference from the second base station is relatively low.

Abstract: The function of comparing power of a signal obtained by multiplying an input signal by an EVM target value and power of a peak suppression signal, and automatically adjusting a peak factor threshold value Vt in such a manner that the values of both power become equal to each other, is added to the peak factor reduction device. The peak factor reduction device is also added with the function of comparing instantaneous amplitude values of a signal Sout after a peak factor reduction and the peak factor threshold value Vt, and automatically calculating a peak detection width N so as to suppress the residual of each peak.

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: 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: Even if a receiver has a normal gain and a lowered intermodulation distortion characteristics, a fault detection is possible. A test signal transmitter sends a test signal having at least two frequencies to a radio receiver through a coupler. A digital signal processing section receives a signal which includes an IM3 component generated by the radio receiver and measures the electric power of fundamental wave components and the IM3 component. Then, the digital signal processing section calculates the gain of the radio receiver and IIP3, which is an index for intermodulation distortion characteristics, of the radio receiver 207 from the calculated electric power. A base station control section determines whether the gain and IIP3 of the radio receiver fall in predetermined ranges to determine whether the radio receiver works normally or has a fault.

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: In a wireless communication system based on an OFDM access system, when forgetting averaging channel estimation is performed, there occurs a phase difference between a present channel estimated value and a past estimated value due to a change of FFT operation timing at a reception side. The error of the channel estimated value caused by the phase difference is corrected. A synchronization catching/tracking unit to determine an operation timing of an FFT from a received signal is provided, and an FFT operation timing difference acquisition section to grasp a change of the operation timing of the FFT generated by the synchronization catching/tracking unit is provided.

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: 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: 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: The present invention is to accommodate a large number of users required in a digital radio communication system and to prevent communication quality from deteriorating. The present invention is to prevent the occurrence of a delay by adding a process for restricting packet assignment for a call having low communication quality. When the average DRC value is equal to or smaller than a threshold, assigned slots are thinned out to improve communication quality for radio terminals close to cell boundaries and to increase the number of radio terminals accommodated. As a method for thinning out assigned slots, packets received from an upper level unit of a radio base station are, for example, discarded before transmission as long as the lowest limit sound quality is maintained. With this operation, the lowest limit sound quality is ensured.

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.