Methods and arrangements in a telecommunication system
The present invention relates to a method and a device for supporting positioning with a minimum of assistance data signalling. The method in the radio device that shall perform the positioning measurements comprises determining ( 440 ) a positioning reference signal pattern, based on a cell identity and a pre-defined mapping between the cell identity and the positioning reference signal pattern, and performing ( 450 ) positioning measurements based on the determined positioning reference signal pattern.
1. A wireless transmit/receive unit (WTRU) for operating in a wireless communication network having a plurality of cells each having a cell identity, comprising: a processor with executable instructions for:
detecting the cell identity of a at least one cell within the wireless communication network;
using the cell identity and a pre-defined mapping table to identify a positioning reference signal pattern for the at least one cell;
performing a correlation for resource elements in the positioning reference signal pattern to obtain a correlation result for the at least one cell; and
using the positioning reference signal pattern for a position measurement if the correlation result exceeds a threshold.
2. The WTRU of claim 1 , wherein the positioning reference signal pattern is identified by one of a frequency shift, a time shift, or a combination of a frequency shift and a time shift.
3. The WTRU of claim 1 , wherein the positioning reference signal pattern is identified by a Costas array.
4. The WTRU of claim 1 , wherein the positioning measurement is an observed time difference of arrival.
5. The WTRU of claim 1 , wherein the processor further comprises instructions for reporting the position measurement to the wireless communication network.
6. A method for determining position measurements in a wireless transmit/receive unit (WTRU) operating in a wireless communication network having a plurality of cells each having a cell identity, comprising:
detecting the cell identity of a at least one cell within the wireless communication network;
using the cell identity and a pre-defined mapping table to identify a positioning reference signal pattern for the at least one cell;
performing a correlation for resource elements in the positioning reference signal pattern to obtain a correlation result for the at least one cell; and
using the positioning reference signal pattern for a position measurement if the correlation result exceeds a threshold.
7. The method of claim 6 , wherein the positioning reference signal pattern is identified by one of a frequency shift, a time shift, or a combination of a frequency shift and a time shift.
8. The method of claim 6 , wherein the positioning reference signal pattern is identified by a Costas array.
9. The method of claim 6 , wherein the positioning measurement is an observed time difference of arrival.
10. The method of claim 6 , further comprising for reporting the position measurement to the wireless communication network.