| 摘要 |
PROBLEM TO BE SOLVED: To aid a radio terminal in judging the position of a navigation satellite according to a signal that is transmitted from the satellite by transmitting the evaluation of PRN synchronization and Doppler shift to the radio terminal being located in a region where a reference position is partially located. SOLUTION: The Doppler shift and PRN synchronization of a satellite signal at a reference position in a cell and a sector where a radio terminal is located are evaluated. The evaluation is based on information that is carried by a GPS signal that is acquired by an auxiliary system or a WAG server. The auxiliary system or the WAG server can be located at a different position from the positions of the radio terminal or the WAG client. The evaluation of the PRN synchronization and Doppler shift is based on some sort of reference time. In this case, the cell that is divided into a base station 201 and a plurality of sectors 202, 203, and 204 is shown. A spot 205 is a point being located within a coverage range or at the center of gravity of the sector 203 and is an example of a reference position in the sector 203. |
