Oki Electric Industry Co., Ltd.

Ikuo Kawasumi

Toshio Kato

Hiroki Sugimoto

Kiyoki Sekine

Kenji Horiguchi

Junji Uehara

There has been such a drawback that it is difficult to accurately estimate the location of mobile station MS in a mobile communication system. To solve the problem, according to the mobile communication system of the present invention, a mobile station and several base station cooperate for estimation. First the base stations BS in which the mobile station is laid and other base stations adjacent thereto each measure the receipt levels of the radio wave radiated by the mobile station to notify the position manage center of the receipt levels. Second the position manage center instructs the mobile station to control the radio wave pursuant to the receipt levels in such a fashion the receipt levels are stabilized; finally. Third each base station measure the distance between the base station and the mobile station based upon the propagation time of the radio wave to inform the position manage center of the distance. Finally, the position manage center estimates the location of the mobile station based upon a point or several points given by the circles defined using the distances.

System and method for estimating location of mobile station

A code-division multiple-access receiver carries out the following steps whenever it recognizes a symbol boundary in the received baseband signal. First, using the despreading code of the relevant station, it estimates the value of the symbol. Next, using the spreading code of the station, it estimates an interference signal, and modifies the baseband signal by subtracting the interference signal. These steps can be iterated for each symbol. The iterations can be organized into stages, with estimated symbol values from one stage passed to the next stage for use in estimating new symbol values in that next stage. At the end, the remaining baseband signal can be used to adjust the final estimated symbol values.

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Tokyo, Japan

Ikuo Kawasumi