Nippon Telegraph and Telephone Corporation

Kohei Suzaki

Yusuke Asai

Hiroyuki Shiba

Ryo Miyatake

Fumihiro Yamashita

Yoshinori Suzuki

A communication system including a mobile station that communicates with a wireless station and moves toward a predetermined destination, and a relay station that relays communication between the mobile station and the wireless station, includes: the mobile station that pauses movement when sensing an obstacle present on a first moving route toward the destination in a case of moving along the first moving route, and moves along a second moving route headed to the destination while avoiding the obstacle when establishing communication between the mobile station and the wireless station via the relay station in a case where the movement is paused; and the relay station that moves so as to keep a position where communication between the mobile station and the wireless station can be relayed according to movement of the mobile station when the mobile station moves along the second moving route.

Communication system and communication method

An interference source hunting method of hunting for an interference source of electromagnetic waves while moving between multiple measurement points, includes the steps of acquiring strength information of electromagnetic waves, estimating a distance from the measurement point to the location of the interference source, based on the strength information, calculating a first presence probability that the interference source is present at each position, based on whether a distance from the measurement point to the position is within the distance, updating second presence probabilities acquired in hunting in the past, based on the first presence probabilities, determining a position obtained by moving, by a predetermined distance, the measurement point toward a position with the second presence probability higher than the second presence probability at the measurement point, as a new measurement point, and determining, in a case where a size of an area in which each of the second presence probabilities is greater than or equal to a predetermined value is less than a predetermined value, that the location of the interference source is within the area.

Interference source searching method and interference source searching apparatus

A control device mounted in a first mobile body that includes a camera and an antenna includes: the camera configured to operate such that a direction of an optical axis of the camera and an oriented direction of the antenna are linked to each other; an identification unit configured to identify a second mobile body through image recognition from a captured image captured by the camera operating; and an antenna control unit configured to control the oriented direction of the antenna such that a position of the identified second mobile body in the captured image is a predetermined position.

Control apparatus, control system and control method

A mobile station control method by a computer for controlling a first mobile station for communicating with a second mobile station includes: distance detecting of detecting a distance between the first mobile station and the second mobile station; and first switching of switching a beam width of an electromagnetic wave emitted from the first mobile station to the second mobile station switching a beam width of an electromagnetic wave emitted from the first mobile station to the second mobile station the distance.

Mobile station control method and mobile station control apparatus

An object is to provide a method and a system of adjusting a power amplifier which makes it possible to adjust a linearizer using signals of two carriers by the same power, to reduce the influence of the non-linearity on a multicarrier signal compared with the conventional. A method of adjusting a power amplifier, the power amplifier including a linearizer to reduce an intermodulation caused by non-linearity of the power amplifier, includes: inputting two signals generated by a signal generator into the power amplifier; measuring power of each order of first intermodulations of the two signals output from the power amplifier; calculating a power sum of second intermodulations by the plurality of signals using the measured power of each order of the first intermodulations; and adjusting the linearizer so that the power sum of the second intermodulations by the plurality of signals takes a minimum value or at most a predetermined value.

Adjusting method and adjusting system for power amplifier

A disclosure relates to a wireless communication system for instructing terminals to control resources based on radio wave conditions. The system comprises: generating, by a base station, information on radio wave conditions based on an uplink wireless signal from terminals, storing learning model data for generating the information on quality of communications with an amount of processing that is equal to or less than a threshold value, selecting learning model data on the basis of known information, and transmitting the learning model data and a downlink wireless signal, receiving, by the terminal, the learning model data, generating information representing the radio wave environment based on the downlink wireless signal, generating information representing quality of communication based on the learning model data and the information representing the radio wave condition, and controlling the communication resource for the wireless signal based on the information representing quality of communication.

Method and system in a wireless communications for estimating quality based on learning model

A measuring robot () measures radio waves using a radio wave measuring unit () at a measurement point. A self-propelled route control unit () controls, in a case that reliability of communication using the radio wave at the measurement point is determined to be low based on one or more of a measurement result by the radio wave measuring unit () and information on an obstacle detected by a terrain/obstacle/position detection sensor unit (), a radio wave measuring unit () to measure the radio wave more precisely compared to the measurement of the electromagnetic wave in a case that the reliability of the communication using the radio wave is determined to be high.

Prorogation environment recognition method and propagation environment recognition apparatus

A synthetic reception strength value in a case of synthesizing indirect waves of radio waves generated due to an obstruction is calculated for each piece of receive antenna coordinate information in consideration of a phase of each indirect wave. Relation information indicating relation between input information and teaching information is generated. The input information is the synthetic reception strength value for each piece of the receive antenna coordinate information corresponding to transmit antenna coordinate information. The teaching information is information indicating a reception state of the radio waves being calculated using a method of actually measuring the radio waves output by the transmit antenna at a position of a receive antenna or a method other than the method of the actual measurement. Strength of the radio waves is estimated by calculating the information indicating the reception state of the radio waves by using the transmit antenna coordinate information for evaluation and the generated relation information.

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Musashino, Japan

Kohei Suzaki