Reference signal time difference (RSTD) measurements for observed time difference of arrival (OTDOA) positioning

1. An apparatus of a user equipment (UE) configured to perform Reference Signal Time Difference (RSTD) measurements for Observed Time Difference Of Arrival (OTDOA) positioning, the apparatus comprising:

one or more processors configured to:

decode a multimedia broadcast multicast service (MBMS) single frequency network (MBSFN) subframe configuration information for one or more cells in a plurality of cells;

decode Positioning Reference Signal (PRS) configuration information for one or more cells in the plurality of cells;

determine, for the one or more cells in the plurality of cells, an existence of a Cell Specific Reference Signal (CRS) for selected subframes of a plurality of subframes based on the MBSFN subframe configuration information;

determine for the one or more cells in the plurality of cells, an existence of a PRS for selected subframes of the plurality of subframes based on the PRS configuration information, wherein the one or more processors are configured to determine the existence of the CRS for selected subframes and the existence of the PRS for the selected subframes for cells that are aligned with the MBSFN subframe configuration of a serving cell of the UE;

measure the RSTD for the one or more cells in the plurality of cells using the CRS and the PRS; and

a memory interface configured to send to a memory the RSTD.

2. The apparatus of claim 1 , wherein the one or more processors are further configured to decode the MBSFN subframe configuration information, wherein the MBSFN subframe configuration comprises a selected subset of full information for a MBSFN subframe.

3. The apparatus of claim 1 , wherein the one or more processors are further configured to decode the MBSFN subframe configuration information, wherein the MBSFN subframe configuration further comprises CRS non-existence information for one or more subframes of the plurality of subframes.

4. The apparatus of claim 1 , wherein the plurality of cells comprises a reference cell and one or more neighbor cells.

5. The apparatus of claim 1 , wherein the one or more processors are further configured to determine the existence of the CRS for the selected subframes of the plurality of subframes in each cell in the plurality of cells.

6. The apparatus of claim 1 , wherein the one or more processors are further configured to determine the existence of the CRS for the selected subframes of the plurality of subframes in a selected cell in the plurality of cells and apply the existence of the CRS for the remaining cells in the plurality of cells based on the MBSFN subframe configuration information.

7. The apparatus of claim 1 , wherein the one or more processors are further configured to decode a MBSFN subframe configuration for a cell to enable the UE to determine when the MBSFN subframe configuration for a cell to inform whether or not the MBSFN subframe configuration of the cell is different from the serving cell of the UE.

8. An apparatus of a user equipment (UE) configured to perform Reference Signal Time Difference (RSTD) measurements for Observed Time Difference Of Arrival (OTDOA) positioning, the apparatus comprising:

one or more processors configured to:

decode a multimedia broadcast multicast service (MBMS) single frequency network (MBSFN) subframe configuration information from a system information block two (SIB-2) for a serving cell in a plurality of cells;

decode an MBSFN subframe alignment of each cell in the plurality of cells with a MBSFN configuration of the serving cell, wherein the one or more processors are configured to decode a one bit signal wherein a bit value equal to “one” indicates MBSFN subframes for the plurality of cells are aligned with the MBSFN subframe configuration of the serving cell and a bit value equal to “zero” indicates that the MBSFN subframes for one or more subframes in the plurality of cells are not aligned with the MBSFN subframe configuration of the serving cell;

determine, for one or more cells in the plurality of cells, an existence of a Cell Specific Reference Signal (CRS) for selected subframes of a plurality of subframes based on the MBSFN subframe alignment of each cell in the plurality of cells;

determine, for the one or more cells in the plurality of cells, an existence of a positioning reference signal (PRS) for selected subframes of a plurality of subframes based on the MBSFN subframe alignment of each cell in the plurality of cells; and

measure the RSTD for the one or more cells in the plurality of cells using the CRS and the PRS; and

a memory interface configured to send to a memory the RSTD.

9. The apparatus of claim 8 , wherein the one or more processors are further configured to decode the MBSFN subframe alignment comprising signaling from the network from a network indicating selected cells from the plurality of cells that are aligned with the MBSFN subframe configuration of the serving cell.

10. The apparatus of claim 8 , wherein the one or more processors are further configured to decode a one bit signal in an OTDOA-reference cell information (OTDOA-ReferenceCellInfo) and an OTDOA-neighbor cell information (OTDOA-NeighborCellInfo).

11. The apparatus of claim 8 , wherein the one or more processors are further configured to determine the existence of the CRS for selected subframes and the existence of the PRS for selected subframes for cells that are aligned with the MBSFN subframe configuration of the serving cell.

12. The apparatus of claim 8 , wherein the one or more processors are further configured to:

decode the MBSFN subframe alignment of each cell in the plurality of cells with the MBSFN subframe configuration of the serving cell to identify one or more cells in the plurality of cells that are not aligned with the MBSFN subframe configuration of the serving cell; and

determine, for the one or more cells in the plurality of cells that are not aligned, an existence of a CRS for subframes 0, 4, 5, 9 of a radio frame and the existence of the CRS in a first orthogonal frequency division multiplexing (OFDM) symbol in subframes 1, 2, 3, 6, 7, 8 of the radio frame.

13. At least one non-transitory machine readable storage medium having instructions embodied there on for supporting an apparatus of a user equipment (UE) configured to perform Reference Signal Time Difference (RSTD) measurements for Observed Time Difference Of Arrival (OTDOA) positioning, the instructions when executed by one or more processors at the UE perform the following:

decoding a multimedia broadcast multicast service (MBMS) single frequency network (MBSFN) subframe configuration information for one or more cells in a plurality of cells;

decoding Positioning Reference Signal (PRS) configuration information for one or more cells in the plurality of cells;

determining, for the one or more cells in the plurality of cells, an existence of a Cell Specific Reference Signal (CRS) for selected subframes of a plurality of subframes based on the MBSFN subframe configuration information;

determining for the one or more cells in the plurality of cells, an existence of a PRS for selected subframes of the plurality of subframes based on the PRS configuration information, wherein determining the existence of CRS and the existence of PRS comprises determining the existence of the CRS for selected subframes and the existence of the PRS for the selected subframes for cells that are aligned with the MBSFN subframe configuration of a serving cell of the UE; and

measuring the RSTD for the one or more cells in the plurality of cells using the CRS and the PRS.

14. The at least one non-transitory machine readable storage medium of claim 13 , further comprising instructions when executed by the one or more processors perform the following:

decoding the MBSFN subframe configuration information, wherein the MBSFN subframe configuration comprises a selected subset of full information for a MBSFN subframe.

15. The at least one non-transitory machine readable storage medium of claim 13 , further comprising instructions when executed by the one or more processors perform the following:

decoding the MBSFN subframe configuration information, wherein the MBSFN subframe configuration further comprises CRS non-existence information for one or more subframes of the plurality of subframes.

16. The at least one non-transitory machine readable storage medium of claim 13 , further comprising instructions when executed by the one or more processors perform the following:

determining the existence of the CRS for the selected subframes of the plurality of subframes in each cell in the plurality of cells.

17. The at least one non-transitory machine readable storage medium of claim 13 , further comprising instructions when executed by the one or more processors perform the following:

determining the existence of the CRS for the selected subframes of the plurality of subframes in a selected cell in the plurality of cells and apply the existence of the CRS for the remaining cells in the plurality of cells based on the MBSFN subframe configuration information.

18. The at least one non-transitory machine readable storage medium of claim 13 , wherein the plurality of cells comprises a reference cell and one or more neighbor cells.

19. The at least one non-transitory machine readable storage medium of claim 13 , further comprising instructions when executed by the one or more processors perform the following:

decoding a MBSFN subframe configuration for a cell to enable the UE to determine when the MBSFN subframe configuration for a cell to inform whether or not the MBSFN subframe configuration of the cell is different from a serving cell of the UE.