| 摘要 |
A method for estimating the distance (d) of a receiver (102) from a radio transmitter (101) includes the steps of: receiving (602) radio signals (103, 701) irradiated by the transmitter (101), which include components from which at least three tones (1,2,3,4) are extracted, each having a different frequency; measuring (606) a first phase difference (&Dgr;&phgr;21) between first two tones (1, 2) of the at least three tones, whose frequencies (f1, f2) have a first spacing, and measuring a second phase difference (&Dgr;&phgr;43) between second two tones (3, 4) of the at least three tones, whose frequencies (f3, f4) have a second spacing, wherein one of the first spacing or second spacing is greater than the other; estimating (607, 611, 613) the distance (d) on the basis of the first phase difference (&Dgr;&phgr;21) and the second phase difference (&Dgr;&phgr;43). |
