| 摘要 |
Methods and systems for radio positioning of a mobile receiver are described. When the mobile receiver (2) is at a first known position (M1), a virtual positioning reference is established by logging the known position (M1) of the mobile receiver (2) together with a local time at which a first instance of a predictably repeated code word is received by the mobile receiver (2) from a terrestrial radio signal transmitter (7). The terrestrial transmitter (7) is assumed to have a known position and the local time is measured relative to a clock local to the mobile device (2). During movement of the mobile receiver (2) from the first known position (M1) to a second unknown position (M2), the local clock is run. When the mobile receiver (2) is at the second unknown position (M2), the local clock is used to determine the time difference between when the virtual positioning reference is predicted to receive a second instance of the code word and when the mobile receiver (2) actually receives the second instance of the code word. From the time difference and the position information of the virtual positioning reference, the position of the mobile receiver (2) at the second position can thus be determined. |
