Abstract: A transmission circuit comprises a ??? modulator to perform ??? modulation of an amplitude modulation component of a modulation signal and to output a pulse width modulation signal, an angle modulator to generate an angle modulation component signal of a signal obtained by multiplying the modulation signal by a transmission output control coefficient corresponding to a transmission output in a power amplifier, and a multiplier to multiply the pulse width modulation signal by the angle modulation component signal and to output a result of the multiplication as an output signal to the power amplifier.

Abstract: A transmission circuit comprises a ??? modulator to perform ??? modulation of an amplitude modulation component of a modulation signal and to output a pulse width modulation signal, an angle modulator to generate an angle modulation component signal of a signal obtained by multiplying the modulation signal by a transmission output control coefficient corresponding to a transmission output in a power amplifier, and a multiplier to multiply the pulse width modulation signal by the angle modulation component signal and to output a result of the multiplication as an output signal to the power amplifier.

Abstract: A matching circuit including a main matching block 51 inserted in a signal path and a series matching block 522, one end of which is connected to the main matching block 51, in which one end of a series connection of a switch 542 and a parallel matching block 532 is connected to the signal path at the other end of the series matching block 522 and impedance matching between input/output is performed at any one of two frequencies by setting the switch to ON/OFF.

Abstract: A resonant element that causes a signal input from an input terminal to resonate at a predetermined resonance frequency and outputs it to an output terminal is provided. The element has a transmission line series including a plurality of transmission lines connected in series with each other and intersecting with a hotline connecting the input terminal and the output terminal and a plurality of switches. At least one of one end and the other end of the transmission line series is a grounded end. The resonant element having first and second end side, each end side having a first transmission line and a second transmission line connected to a switch having a grounded end. The resonance frequency is switched by turning on/off the switch to change the sum of the lengths of the transmission lines through which the signal passes.

Abstract: Provided is a mobile communication system capable of determining a communication path to implement fast communication by multihop connection. A mobile communication system (1) comprises a mobile station (10), at least one relay station (30), and a base station (20) and implements packet transmission from the mobile station (10) to the base station (20) through a communication path with an intermediary of at least one relay station (30) or through a communication path without an intermediary of a relay station. The mobile communication system (1) 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 (30) constituting a communication path between the transmitting station and the receiving station, and at the base station (20).

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: What is disclosed is a resonant element that causes a signal input from an input terminal to resonate at a predetermined resonance frequency and outputs it to an output terminal.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A variable resonator is provided which comprises signal conductor 13 formed on top side surface of dielectric substrate 12, ground conductor layer 11 formed on back side surface thereof and switches 14, wherein signal conductor comprises a plurality of first conductor lines 13-1 and second conductor line 13-2 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, switches 14 are 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.

Abstract: 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.

Abstract: Provided is a mobile communication system capable of determining a communication path to implement fast communication by multihop connection. A mobile communication system (1) comprises a mobile station (10), at least one relay station (30), and a base station (20) and implements packet transmission from the mobile station (10) to the base station (20) through a communication path with an intermediary of at least one relay station (30) or through a communication path without an intermediary of a relay station. The mobile communication system (1) 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 (30) constituting a communication path between the transmitting station and the receiving station, and at the base station (20).

Abstract: Provided is a mobile communication system capable of determining a communication path to implement fast communication by multihop connection. A mobile communication system (1) comprises a mobile station (10), at least one relay station (30), and a base station (20) and implements packet transmission from the mobile station (10) to the base station (20) through a communication path with an intermediary of at least one relay station (30) or through a communication path without an intermediary of a relay station. The mobile communication system (1) 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 (30) constituting a communication path between the transmitting station and the receiving station, and at the base station (20).

Abstract: A plurality of one-quarter wavelength coplanar resonators 5a to 5d are formed in series on a dielectric substrate 1, and coplanar input/output terminal sections 4a and 4b are formed on the dielectric substrate at opposite ends of the series connection for coupling with resonators 5a and 5d, respectively. A center conductor line width w1 of each of the resonators 5a to 5d is equal to a center conductor line width wio of each of the input/output terminal section 4a and 4b, but a ground conductor spacing d1 of each of the resonators 5a to 5d is greater than a ground conductor spacing dio of each of input/output terminal section 4a and 4b. Maintaining the accuracy of design is facilitated and a reduction in the maximum current density in the resonator is enabled.

Abstract: 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.

Abstract: A data link transmission control method of performing data link transmission control comprises automatic repeat request control for transmission/reception of a packet between a mobile station and a plurality of base stations indicated in FIG. 11, wherein a first base station stores and makes a copy of packet in which identification information specifying the packet has been added to packet addressed to the mobile station, wherein the first base station delivers the packet copy to a second base station, wherein the second base station stores the delivered packet copy, and wherein one or more base stations comprising the first base station transmit to the mobile station the packet accompanied by the identification information, or the delivered packet copy.