54results about How to "Improve frequency utilization efficiency" patented technology

In a wireless communication system, a plurality of base stations each comprise a plurality of cells and a terminal communicates with the base stations. Each of the base stations is equipped with one or a plurality of antennas. The base stations transmit first reference signals that do not overlap with at least those of neighborhood base stations and are unique to the antennas. The terminal receives the first reference signals, estimates the reception powers of the first reference signals transmitted from the respective antennas, selects, based on the estimation results of the reception powers, a plurality of the antennas suitable for communication, and transmits the antenna selection results to the base stations. The base stations refer to the antenna selection results transmitted from the terminal to assign the antennas belonging to the different cells to the terminal and notify the terminal of the results of assigning the antennas.

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, on the basis of the transmission power amount, and transmits the packet by a power of the transmission power amount to the source station determined as a packet-transmissible station. On this occasion, an interference signal is weakened by assignment of channel groups 1, 2 for transmission of signals.

The present invention suppresses to a minimum the degradation of the transmission quality caused by chromatic dispersion characteristic of an optical transmission medium, and the interplay between the chromatic dispersion and non-linear optical effects in dense WDM transport systems. A baseband input data signal is pre-coded in advance by a pre-coding unit, phase modulation is carried out using a pre-coded signal by the optical phase modulating unit, and the phase modulated optical signal is converted to an RZ intensity modulated signal by the optical filter unit that performs phase-shift-keying to amplitude-shift-keying conversion. For example, an optical phase modulating unit generates an encoded DPSK phase modulated signal using a differential phase shirt keying (DPSK) format, and a phase modulated signal is converted to an RZ intensity modulated signal by the optical filter unit disposed downstream of the optical phase modulating unit.

A multicarrier communication method capable of improving the frequency utilization efficiency and the throughput of the communication system, while satisfying the QoS. A communication terminal reports the CQI about all of the subchannels included in the bandwidth of a communication channel during a first CQI report, as shown in the upper figure portion. Unlike the first report, during the second and following CQI reports, in which much time is left in terms of the permissible delay time, the communication terminal reports the CQI only about subchannels 1 and 2 assigned by the second and following frequency assignments, as shown in the lower figure portion.

The present invention makes up for shortages of a central control type and a distributed control type radio communications systems, not only restrains interference of radio stations using the same radio communications system, and also restrain the interference of the surrounding radio stations, thereby effectively using a frequency source. The radio communications system includes a radio station connecting with a network (a network connecting radio station) and a counterparty radio station. The network connecting radio station obtains information A of a radio communication status through the network and transmits to the counterparty radio station. The information A comprises using frequency information of the radio station and waveform characteristic quantity information indicating statistic properties of signal waveforms transmitted by the radio station. The counterparty radio station calculates a measured value of the waveform characteristic quantity of the signal received from another radio station and reports the measured value to the network connecting radio station aiming at each part of the announced waveform characteristic quantity. The network connecting radio station determines whether to communicate or not and a radio source according to the information A and the information reported by the counterparty radio station.

when the SC-FDMA method is used in combination with the multi-antenna transmission technique, a radio transmission method effectively improves the frequency use efficiency by performing appropriate frequency allocation to a plurality of antennas while suppressing degradation of the reception quality caused by interference. In the radio transmission method of the SC-FDMA type, according to the number of terminals simultaneously accessing a base station within a usable frequency band, it is possible to allocate all the transmission signals (transmission stream) to be transmitted by different antennas to different frequency bands or to use the MIMO transmission in combination. Moreover, according to the number of terminals making an access, the number of terminals which perform the MIMO transmission can be varied.

A base station apparatus and a channel allocation method are disclosed. The task of the invention is to improve the frequency using efficiency. A base station (12) includes an array antenna composed of a plurality of antenna elements (20-1 to 20-4), and uses at least one part of the plurality of antenna channels to communicate with the mobile station. The base station (12) comprises: an adaptive control unit for obtaining weights (w1' to w4') of antenna elements (20-1 to 20-4) indicating an arrival direction of an interference signal detected on a radio channel that is not being used for communication, and weights (w1 to w4) indicating an arrival direction of a desired signal arriving from a mobile station. The base station further includes an interference signal suppressibility determining unit (34) for determining, based on the weights (w1 to w4) and the weights (w1' to w4'), whether or not it is possible to form a direction pattern that directs a main beam toward the arrival direction of the desired signal and directs a null toward the arrival direction of the interference signal; and a channel allocation unit (36) for determining, based on a result of the determination, whether to allocate the mobile station the radio channel on which the interference signal is detected.

The invention provides a mobile communication system, a mobile station device, a base station device and a mobile communication method. The mobile communication system includes a mobile station device and base station devices. The mobile station device includes a reception quality measuring unit for measuring the reception qualities according to the signals transmitted from base station devices near the mobile station device, a determining unit for determining a base station device to communicate with the mobile station device according to the service which the mobile station device requests and the measured reception quality, and a communicating unit for communicating with the determined base station device.

Provided is a communication device, which constitutes a wireless communication system together with a base station and a terminal station and relays and transfers a signal transmitted and received between the base station and the terminal station. The communication device is characterized in that, when the communication device receives a signal transmitted from the base station or the terminal station, the communication device uses a frequency different from a frequency at the time of the receiving and transfers the received signal after amplifying the same.

A base station device that carries out carrier sense to ensure a wireless medium for a prescribed period, sets an uplink communication period in at least a portion of the prescribed period, selectively or simultaneously sets a first communication mode and a second communication mode in at least one uplink subframe period that is included in the uplink communication period, and transmits a downlinksubframe including common control information that indicates the communication mode that is set to the uplink subframe period, the first communication mode allowing a terminal device to communicate on the basis of the scheduling information of the base station device, and the second communication mode allowing the terminal device to communicate without requiring the scheduling information of thebase station device.

Provided are a terminal device, a base station device and a communication method which can improve reliability and frequency utilization efficiency when using beamforming for transmission. The terminal device comprises a reception unit that receives a downlink shared channel including configuration information, downlink control information and transport blocks, and a signal detection unit that uses the redundancy version included in the downlink control information to decode the downlink shared channel. The configuration information includes the number of consecutive slots in which the same transport block will be repeatedly transmitted. A demodulation reference signal (DRMS) to be transmitted in at least two of the consecutive slots is not related to quasi-colocation (QCL). The redundancy version is determined from the slot index of the consecutive slots, and information indicating the QCL.

Provided is a wireless communication device capable of setting a wireless LAN base station so that the overall frequency utilization efficiency of a wireless communication system including wireless LAN base stations of different models of different manufacturers can be improved. A wireless communication system that performs settings necessary for operating a wireless LAN base station constituting a wireless communication network includes an information collecting unit that collects setting information set in the wireless LAN base station and a wireless environment in the wireless LAN base station. information; a parameter calculation unit that obtains parameters that should be set for the wireless LAN base station of the collection source based on the collected setting information and wireless environment information; and a parameter setting unit that transmits the required parameters to the wireless LAN base station of the collection source via the network. Get the parameters and set the parameters.

The coverage area of a transmission device is expanded by relaying, and frequency utilization efficiency (cell throughput) is improved. Disclosed is a relay device that transmits signals received from a transmission device by a reception device. The relay device is equipped with a received signal processing unit (33) that demodulates the signals received from the transmission device, a selection unit (34) that selects a transmission method that can be demodulated by the reception device from multiple transmission methods, and signal generation units (35a, 35b) that generate signals used by the transmission method selected by the selection unit (34) based on the signals demodulated by received signal processing unit (33).