Enhanced-Observed Time Difference
Enhanced-observed time difference (E-OTD) is similar to time difference of arrival (TDOA), but is a handset-based positioning solution rather than a network-based solution. E-OTD takes the data received from the surrounding base stations to measure the difference in time it takes for the data to reach the terminal (see Figure 5.7). The time difference is used to calculate where the mobile device is in relation to the base stations. For this to work, the location of the base stations must be known and the data sent from the different base stations must be synchronized.
Figure 5.7. E-OTD.
Base stations are typically ...