Hitachi, Ltd.

Kokusai Electric Co., Ltd.

Hitachti, Ltd.

Hideya Suzuki

Atsushi Ogino

Tomoaki Ishifuji

Nobukazu Doi

Arata Nakagoshi

Takashi Yano

Katsuhiko Tsunehara

Ryota Yamasaki

Tsuneo Furuya

Yoshinobu Yamamoto

Kazuhiro Suzuki

Hiroshi Kuwahara

Masaaki Shida

Kenzo Urabe

Kenichi Mizugaki

Koji Watanabe

Kenzaburo Fujishima

Yukinari Fujiwara

Yasuaki Kinoshita

Masahiro Koya

Yohichi Ogawa

Noriyuki Sugiura

Michiaki Kurosawa

Isao Shimbo

Naoto Matsuzawa

Toshikazu Sasa

Hideo Nakasawa

A wireless communication system for high-speed motion use, capable of shortening the frequency channel search time and increasing the communication time available for service. The system includes an access point communicating on a designated one frequency channel and a mobile terminal communicating on the same received channel by receiving radio waves transmitted by the same access point. As for mobile terminal, in a storage, priority data is stored for a channel search in which arbitrary priorities can be set respectively for the channels. Frequency channel search sequence data, set up so that the number of times of appearance becomes greater for channels for which the priority data are set higher, are generated on the basis of the relative data, and a search of communication-capable channels is carried out in accordance with the same channel search sequence data.

Mobile terminal and wireless communication system

A method, system, and apparatus are provided for detecting a position of a terminal in a network accurately without a GPS receiver. In one example, a method for locating a position of a terminal includes calculating a position of a base station; detecting a clock time difference between the base station and another base station; measuring a reception timing of a signal received by the base station from the terminal; and locating the position of the terminal using at least the position of the base station, the clock time difference, and the reception timing.

Method, system, and apparatus for detecting a position of a terminal in a network

A radio signal receiving method grasps features of a propagation path at the start of communication and generates a template waveform corresponding to the features. A receiver examines a reception waveform of a propagation path condition judgment portion contained in a header portion of a packet, individually generates the template waveform in each communication session and performs correlation detection on the basis of the template waveform generated individually.

Radio signal receiving method and radio signal receiver

A method and system for detecting the position of a mobile unit efficiently and with high precision in a multipath environment. A wireless position detection system made up of a mobile station containing a wireless communication means to allow sending and receiving multiple to and from mutually different antenna positions and, a base station for performing wireless communication with mobile stations containing a wireless communication means and, multiple wireless receivers for receiving each of the multiple signals sent by the wireless communication means between the base stations and, a server for detecting the position of the mobile station from each wireless receiver and from the position of the base station, and the time relating to received signals measured by the multiple wireless receivers.

Wireless position measurement method and wireless position measurement system

A time slot for a connection request sent from a mobile station includes the mobile station ID and the application discrimination word of the object application for which the mobile station requests the connection. By referring to the database, a base station assigns a MDC preferentially to a mobile station issuing a connection request for calling a high priority application. The base station monitors the MDCs used for ongoing communications. If a MDC assigned to a mobile station does not satisfy a predetermined radio communication quality, other MDCs for lower priority application are freed and reassigned to the mobile station. A plurality of MDCs including the reassigned MDCs into which the same contents are encapsulated are transmitted to the mobile station.

Digital radio communication system for multi-application

In calculation of a position of a terminal, there arises, when creating a delay profile, a problem to select a transmission code for a sector of a base station to create the delay profile. According to a position of a base station and a bearing of each antenna forming a sector of the base station, a wireless position calculation method selects a transmission code for a sector of a base station to create a delay profile. Under a condition that the number of delay profiles to be created is limited, each delay profile is created in consideration of the antenna bearing. Therefore, the number of base stations at mutually different positions is increased to calculate the position and precision of the position calculation is improved.

Position calculation method and a mobile terminal and a server therefor

In order to provide a software defined radio and an approval system of a radio which can flexibly cope with specification alteration, a software defined radio includes a storage for holding transmission and reception characteristic information serving as a specification criterion; and a control unit for comparing a measured value obtained from a measurement circuit with the information of the specification criterion and conducting setting of the radio so as to satisfy the specification.

Software defined radio and radio system

A server which provides information related to a service instructs positioning accuracy to a mobile terminal in accordance with a content of a requested service. The mobile terminal changes a position detecting method in accordance with the set positioning accuracy.

Terminal and server for mobile terminal positioning system

In a P-MP fixed wireless access system using quasi-millimeter and millimeter wave bands, a relaying path is autonomously set up for subscriber stations without the need for additional provision of a repetition radio circuit using a costly MMIC. A subscriber station in the fixed wireless access system is provided with a repeating function for relaying signals between a different subscriber station and a base station, a buffer memory for temporarily storing signals to be communicated therebetween, and a table for registering information for identifying a relaying path between an own reference wireless station and a lower-level subscriber station for signal repetition. The base station is provided with a table in which, in order to perform signal communication with an arbitrary subscriber registered in the base station, routing information is registered for determining whether or not to set up a relaying path via a different subscriber station registered in the base station.

Fixed wireless access system and apparatus therefor

In the conventional diversity reception, information included in each non-selected signal does not contribute to an improvement in the reliability of communications, and transmitting power has been dissipated to satisfy required communication quality. Owing to the setting of encoding in respective base stations to injection, signals each including the same contents, which are received by a mobile station, are used for increasing the reliability of communications without depending on the number of the signals which were capable of being received by the mobile station, to thereby reduce transmitting power for satisfying required communication quality.

Diversity wireless communication method and its wireless communication apparatus

A radio communication system and a traffic channel assignment method for realizing the assignment of traffic channels capable of improving the efficiency of use of frequency in the case where the traffic density is high and improving a radio link quality in the case where the traffic density is low. A base station judges the traffic density from a carrier to interference power ratio (CIR) on each channel capable of being selected as a traffic channel. In the case where the traffic density is low, a traffic channel assignment mode selecting an available channel having a greater CIR is assigned as a traffic channel to a mobile station. In the case where the traffic density is high, a traffic channel assignment mode selecting an available channel having a smaller CIR is assigned as a traffic channel to the mobile station. Thereby, it is possible to structure a radio communication system which can cope with the condition of the traffic density of the neighborhood.

Traffic channel assignment based on traffic density and signal quality

With respect to a mobile communication system, intelligence learns a cell boundary where the field strength of adjacent base stations becomes equal, by measuring field strength of communications, and from this data determined and stored over a period of time, the intelligence calculates the position and velocity vector of each mobile unit, from which a priority for hand-off can be determined. Hysteresis of the hand-off is determined with respect to hand-off boundaries located a fixed distance from the measured cell boundary, with hand-off preferably being soft hand-off within the narrow hand-off boundaries. Priority is particularly determined using fuzzy logic and calculation of the time estimated for the mobile unit to reach the cell boundary. Battery consumption of the mobile units is improved by prolonging the interval of checking the position of mobile units, when the mobile units are moving slowly or not moving at all. The determination of the cell boundary is updated continuously, to compensate for environment changes affecting field strength.

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Ichikawa, Japan

Hideya Suzuki