Nippon Telegraph and Telephone Corporation

Tadashi Mori

Tomoki Murakami

Masaru Miyamoto

Tomoaki Ogawa

Hiroshi Sakamoto

Masamichi Hosoda

Makoto Umeuchi

Yasushi Hanakago

Provided is a position estimation method in which a measurement signal and a response signal are transmitted and received between multiple n wireless stations respectively provided with known antennas installed at known positions different from each other and a wireless terminal station provided with a terminal antenna, RTT, which is a round-trip delay time of the transmission and reception, and RSSI, which is a strength of received radio waves of the signals, are measured, and a position of the wireless terminal station is estimated. The method includes: obtaining, as the position of the wireless terminal station, a solution of simultaneous equations of an RTT evaluation function ffor evaluating the estimate value of the position of the wireless terminal station that is estimated based on the RTT measured between the wireless terminal station and the known antenna i (i=1, 2, . . . , n), and an RSSI evaluation function ffor evaluating the estimate value of the position of the wireless terminal station that is estimated based on the RSSI, or a value obtained by searching for an estimate value so that an error evaluation function fobtained by combining the RTT evaluation function and the RSSI evaluation function is minimum.

Position estimation method, position estimation system, position estimation server, and position estimation program

An object is to enable high-accuracy position estimation of a wireless terminal station by efficiently performing connection between a wireless base station and the wireless terminal station using multiple distributed antennas. A position estimation apparatus configured to estimate a position of a wireless terminal station between a wireless base station that can perform transmission and reception by switching between a plurality of distributed antennas arranged in a distributed manner via cables with known lengths, and the wireless terminal station configured to communicate with the wireless base station, includes: a means 1 for measuring a no-delay RTT or measuring a statistical processing RTT when the wireless base station exchanges a measurement signal and a response signal with the wireless terminal station in each of the distributed antennas and measures an RTT, which is a round trip time between the wireless base station and the wireless terminal station, a delay time having been removed from the no-delay RTT using a reception time of the measurement signal and a transmission time of the response signal, and the statistical processing RTT being measured using statistical processing for making the delay time constant using a plurality of instances of exchanging a measurement signal and a response signal; and means 2 for estimating the position of the wireless terminal station based on the no-delay RTT or the statistical processing RTT of each of the distributed antennas.

Position estimation method and position estimation apparatus

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Musashino, Japan

Tadashi Mori