Ntt Docomo, Inc.

Ntt Mobile Communications Network, Inc.

Nippon Telegraph and Telephone Corporation

Ntt Bocomo, Inc.

Ntt Communications Network, Inc.

Yasushi Yamao

Narumi Umeda

Shogo Ito

Tetsuo Hirota

Hitoshi Yoshino

Lan Chen

Shoichi Narahashi

Yasunori Suzuki

Toru Otsu

Shinzo Ohkubo

Atsushi Fujiwara

Shinji Takeda

Hijin Sato

Shinji Mizuta

Toshio Nojima

Hirohito Suda

Kei Satoh

Ichiro Okajima

Hiroshi Okazaki

Yuji Aburakawa

Yoshiaki Tarusawa

Daisuke Koizumi

Takayuki Mizuki

Shigeki Saito

Fumiyuki Adachi

Atsushi Fukuda

Kunihiro Kawai

Hiroyuki Kawai

Tadao Takami

Ning Chen

Takuya Shinozaki

Yoshifumi Suzuki

Shigeru Tomisato

Setsuya Ohashi

Kouji Chiba

Kobaruto Shimada

Hitochi Yoshino

A matching circuit including a main matching blockinserted in a signal path and a series matching block, one end of which is connected to the main matching block, in which one end of a series connection of a switchand a parallel matching blockis connected to the signal path at the other end of the series matching blockand impedance matching between input/output is performed at any one of two frequencies by setting the switch to ON/OFF.

Matching circuit

Provided is a mobile communication system capable of determining a communication path to implement fast communication by multihop connection. A mobile communication system () comprises a mobile station (), at least one relay station (), and a base station () and implements packet transmission from the mobile station () to the base station () through a communication path with an intermediary of at least one relay station () or through a communication path without an intermediary of a relay station. The mobile communication system () is provided with a communication path determiner for determining a communication path with a largest communication speed or a communication path satisfying a required line quality, based on interference levels of respective signals received at a relay station () constituting a communication path between the transmitting station and the receiving station, and at the base station ().

Mobile communication system, transmitting station, receiving station, relay station, communication path determining method, and communication path determining program

A mobile communication system determines a communication path to implement fast communication by multihop connection. A mobile communication system includes a mobile station, at least one relay station, and a base station and implements packet transmission from the mobile station to the base station through a communication path with an intermediary of at least one relay station or through a communication path without an intermediary of a relay station. The mobile communication system is provided with a communication path determiner for determining a communication path with a largest communication speed or a communication path satisfying a required line quality, based on interference levels of respective signals received at a relay station constituting a communication path between the transmitting station and the receiving station, and at the base station.

A mobile communication system capable of determining a communication path to implement fast communication by multihop connection. The mobile communication system includes a mobile station, at least one relay station, and a base station and implements packet transmission from the mobile station to the base station through a communication path with an intermediary of at least one relay station or through a communication path without an intermediary of a relay station. The mobile communication system is provided with a communication path determiner for determining a communication path with a largest communication speed or a communication path satisfying a required line quality, based on interference levels of respective signals received at a relay station constituting a communication path between the transmitting station and the receiving station, and at the base station.

Mobile communication system, transmission station, reception station, relay station, communication path deciding method, and communication path deciding program

A timeslot selection method is provided. The timeslot selection method includes the steps of: obtaining a propagation loss; receiving an occupation state and an interference amount of an uplink timeslot; obtaining a desired wave power from the propagation loss; obtaining a ratio between the desired wave power and the propagation loss for the uplink timeslot in which the occupation state is idle; and selecting the transmitting timeslot by using the ratio. In addition, a timeslot assignment method in which there are a plurality of TDD boundaries each of which is a boundary between at least an uplink timeslot and at least a downlink timeslot in a frame is provided. Furthermore, a timeslot assignment method is provided, in which assignment is carried out according to a service class included in a QoS request.

Method, base station and mobile station for timeslot selection and timeslot assignment

The object is to control interference in a permissible range by applying the CDMA system to signal collision in the conventional CSMA and TDMA base multihop systems and to relax the hidden terminal problem and others to enhance the throughput of the entire system by grouping of channel groups in multihop transmission and by control of transmission based on an interference level from another station. A multihop relay station calculates a desired signal level, for example, from an interference level at its own station of a packet sent from a mobile station, and notifies the mobile station of the desired signal level; and the mobile station calculates a transmission power amount of a packet from the desired signal level, determines whether the packet is transmissible to the station as a source of the desired signal level, and transmits the packet to the source station determined as a packet-transmissible station.

Radio communication system, base station, relay station, mobile station, and packet transmission control method

A packet transmission method in which packets are transmitted between a base station and a mobile station communicating with the base station includes the steps of: recognizing the size of each of the packets to be transmitted; determining a transmission rate for each packet in accordance with the recognized size of the packet; allocating a radio resource to the transmission of each packet between the base station and the mobile station based on the determined transmission rate; and transmitting each packet between the base station and the mobile station using the allocated radio resource. In the method, a modulation method or a radio resource used for transmitting the packets is determined by calculating a transmission rate in a wireless area according to the size of each packet and a transmission request in the wireless area. The transmission request is recognized by the base station from an upper network when the packets are transmitted downward, while calculated by the base station based on a user request and a transmission state of the upper network when the packets are transmitted upward. Therefore, end-to-end quality of service can be provided.

Packet transmission method, base station and mobile station

A digital predistorter compensates for nonlinear distortion of a power amplifier using a power series model. The digital predistorter includes a distortion generating unit configured to introduce a nonlinear distortion component of a prescribed order into a digital input signal supplied to the digital predistorter. The distortion generating unit has a multiplier configured to raise the digital input signal to a power consistent with the prescribed order of the nonlinear distortion component, and a finite impulse response filter connected in series with the multiplier. The digital predistorter also includes an adaptive controller configured to receive a reference signal and adaptively adjust the tap coefficient of the finite impulse response filter so as to bring the reference signal to a desired level.

Digital predistorter using power series model

In a relay terminal A for relaying packet communication between a destination terminal C located outside a service area of a base station Z, and the base station Z, a contribution to relaying is measured and the measurement result is transmitted to a billing server SA configured to store an information communication charge of the relay terminal A, whereby it becomes feasible to give the relay terminal an incentive.

Relay terminal, base station, charging server, communication system, charging method, program computer data signal, and storage medium

A variable resonator is provided which comprises signal conductorformed on top side surface of dielectric substrate, ground conductor layerformed on back side surface thereof and switches, wherein signal conductor comprises a plurality of first conductor lines-and second conductor line-connected with all of first conductor lines, each first conductor line has a width larger than that of second conductor line to thereby a signal path through which high-frequency electric signal passes and which is longer than length of second conductor line is provided, switchesare connected to the ends of first conductor lines, whereby selectively opening and closing switches will electrically disconnect and interconnect interspaces between ends of first conductor lines to thereby vary length of signal path and thus change resonance frequency.

Variable resonator and variable phase shifter

In a method and an apparatus of transmitting a burst signal when the burst signal is transmitted from a transmitting station to a receiving station at a transmission power value and/or a transmission rate determined in accordance with a state of a radio channel between the transmitting and receiving station in a mobile communication system, based on a comparison result between a criterion predetermined according to a state of the radio channel and/or a transmission waiting state of the signal, whether or not the burst signal is to be transmitted is determined, and, when it is determined that the burst signal is to be transmitted, the burst signal is transmitted from the transmitting station to the receiving station.

Method and device for transmitting burst signal in mobile communication system, information distribution method, and information distribution controller

A plurality of one-quarter wavelength coplanar resonatorstoare formed in series on a dielectric substrate, and coplanar input/output terminal sectionsandare formed on the dielectric substrate at opposite ends of the series connection for coupling with resonatorsand, respectively. A center conductor line width wof each of the resonatorstois equal to a center conductor line width wof each of the input/output terminal sectionand, but a ground conductor spacing dof each of the resonatorstois greater than a ground conductor spacing dof each of input/output terminal sectionandMaintaining the accuracy of design is facilitated and a reduction in the maximum current density in the resonator is enabled.

Coplanar waveguide filter and method of forming same

A communication method used when a mobile station receives a signal from a base station in a mobile communication system is provided. The method includes the steps of: deciding one or a plurality of mobile stations which can communicate with the mobile station via a predetermined wireless network and which can receive a signal from the base station; the one or a plurality of mobile stations sending a signal destined for the mobile station received from the base station to the mobile station via the predetermined wireless network; and the mobile station synthesizing a signal received from the base station and the signal destined for the mobile station received from the one or a plurality of mobile stations.

Method and device for communicating via an ad-hoc wireless network

A filter is provided which maintains a low insertion loss characteristic of a filter contained in a casing with a very simple construction that the internal wall of the casing is formed by a superconductor. A coplanar waveguide filtercomprises a dielectric substrate, a plurality of resonatorsandand input/output terminal sectionsand, each of which is formed by a center conductorand ground conductorsand, both formed on the same surface of the dielectric substrate, with the ground conductorstobeing formed on the opposite sides of and in parallel relationship with the center conductor. The filteris contained within a casinghaving an internal wall, the surface of which is formed with a layer of superconductor. By way of example, a high temperature superconductor such as lanthanum-, yttrium-, bismuth- or thallium-superconductor is deposited as a film on a substrate of a metal oxide material such as MgO, SrTiO, LaGaO, LaAlOto provide a superconductor filmed substrate, which is applied to the internal surface of the casing. Electromagnetic power which is irradiated from the filterdoes not produce a power loss when it impinges on the layer of superconductorin its superconducting state, but is reflected therefrom to be absorbed by the filter, thus reducing the filter insertion loss.

Casing contained filter

A combined signal of a digital pilot signal and a digital transmission signal is applied to a digital predistorter (), wherein it is added with odd-order distortions based on a power series model to generate a predistorted signal, then the predistorted signal is converted by a DA converter () to an analog signal, then the analog signal is upconverted by a frequency upconverting part () to a send frequency band, and the upconverted signal is output after being amplified by a power amplifier (). A pilot signal component is extracted from the power amplifier output, then odd-order distortion components of the power series model are extracted by a digital predistorter control part () from the pilot signal component, and the odd-order distortions in the digital predistorter () are controlled to decrease the levels of the distortion components.

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Yokosuka, Japan

Yasushi Yamao