Hitachi, Ltd.

Dan Xu

Shiro Mazawa

Hirotake Ishii

Tsutomu Uchida

Yuichiro Katsu

Shinichi Nakamura

Noboru Fujita

Daisuke Okabe

Koichi Aratani

Thanh Hai Vo

Provided is an information system and an information collection method that are capable of acquiring desired site data while preventing an increase in cost. A link logic definition unitholds a link logic that is definition information defining a correspondence relation between an item value of the site data and a reference value that is an external value of transaction data used for acquiring the item value. A link logic data acquisition unitacquires the item value of the site data by using the link logic.

Information system and information collection method

An OFDM demodulator which does not require a reference signal for synchronization of carriers and can reduce influence of phase rotation by a propagation path when carrier synchronization is made. The OFDM demodulator performs Fourier transform plural times in 2 or more different operation ranges for the same OFDM symbol, calculates phases of sub carriers from the plural-time results of the Fourier transform, compares the calculated phases for each of the plural-time results of the Fourier transform and detects an error in frequency of reproduction carrier from the compared results.

Orthogonal frequency division multiplexing demodulator

In a radio communication system wherein radio frequencies for communicating with a radio terminal are different in radio base stations, a table in which positional information, information on the frequency used for transmission/reception to/from the terminal, and a decision condition in a handoff operation are stored as to each base station is prepared in a base station controller beforehand. When the positional information is received from the radio terminal, the base station controller selects the base station being a handoff candidate, on the basis of the positional information of the radio terminal, the positional information of each base station and the decision condition of the handoff operation with reference to the table, and it transmits a handoff request message which contains the information on the frequency of the base station being the handoff candidate, to the radio terminal through the base station communicating with the radio terminal.

Radio access terminal, base station controller, and handoff control method in radio communication system

Growing community of inventors

Fujisawa, Japan

Dan Xu