Method and apparatus for transmitting/receiving positioning reference signal in wireless communication system

1. A wireless user device comprising:

an antenna;

a transceiver to receive, via the antenna, narrow-band (NB) positioning reference signal (PRS) configuration information comprising an NB PRS bitmap indicating a pattern associated with NB PRS time resources, wherein at least one of the NB PRS time resources comprises an NB PRS for positioning the wireless user device; and

a processor configured to:

receive, via first radio frames of a cell and based on a plurality of repetitions of the NB PRS bitmap, a first NB PRS mapped in at least one of first NB PRS time resources of the cell, wherein an NB PRS muting indicator indicates that the first radio frames of the cell are not muted; and

generate, based on the first NB PRS, a reference signal time difference (RSTD),

wherein the transceiver transmits the RSTD.

2. The wireless user device of claim 1 , wherein the NB PRS bitmap has a size of 10 consecutive bits respectively corresponding to 10 subframes in each radio frame, and

wherein each of the first NB PRS time resources corresponds to one subframe.

3. The wireless user device of claim 1 , wherein the NB PRS bitmap has a size of 40 consecutive bits respectively corresponding to 40 subframes of four consecutive radio frames, and

wherein each of the first NB PRS time resources corresponds to one subframe.

4. The wireless user device of claim 1 , wherein the processor is configured to:

determine, from a plurality of radio frames of a neighbor cell and based on a plurality of repetitions of the NB PRS bitmap, NB PRS time resources of the neighbor cell.

5. The wireless user device of claim 1 , wherein the processor is configured to:

determine, based on value ‘1’ assigned to n-th bit of the NB PRS bitmap, n-th subframe of a radio frame as an NB PRS time resource.

6. The wireless user device of claim 1 , wherein the processor is configured to:

determine a second NB PRS associated with a second cell;

generate, based on the second NB PRS, a second RSTD;

determine a third NB PRS associated with a third cell; and

generate, based on the third NB PRS, a third RSTD.

7. The wireless user device of claim 1 , wherein the transceiver receives a physical resource block (PRB) index indicating one PRB,

wherein the processor is configured to determine a frequency band corresponding to the one PRB and assigned to the wireless user device, and

wherein the first NB PRS is mapped in the frequency band.

8. The wireless user device of claim 1 , wherein the transceiver receives the NB PRS muting indicator, and

wherein the NB PRS muting indicator has a size of k consecutive bits respectively corresponding to k consecutive radio frames, where k is an integer selected from 2, 4, 8, or 16.

9. The wireless user device of claim 8 , wherein the processor is configured to:

determine, based on a value of n-th bit of the NB PRS muting indicator, whether NB PRS subframes in n-th radio frame of the k consecutive radio frames are muted.

10. The wireless user device of claim 1 , wherein one bit of the NB PRS muting indicator corresponds to four consecutive radio frames.

11. The wireless user device of claim 1 , wherein the NB PRS configuration information further comprises the NB PRS muting indicator comprising a plurality of bits,

wherein at least one bit of the plurality of bits of the NB PRS muting indicator has a first value that indicates that the first radio frames of the cell are not muted, and

wherein at least one bit of the plurality of bits of the NB PRS muting indicator has a second value that indicates that the first radio frames of the cell are muted.

12. The wireless user device of claim 1 , wherein the transceiver is configured to receive PRS configuration information comprising:

a PRS configuration index;

a PRS periodicity; and

a PRS subframe offset, and

wherein the received PRS configuration information is different from the received NB PRS configuration information.

13. The wireless user device of claim 1 , wherein a first bit of the NB PRS bitmap has a first value that indicates an NB PRS time resource comprising the first NB PRS, and

wherein a second bit of the NB PRS bitmap has a second value that indicates an NB PRS time resource not comprising an NB PRS.

14. A base station comprising:

an antenna;

a processor configured to:

determine a narrow-band (NB) positioning reference signal (PRS) bitmap indicating a pattern associated with NB PRS time resources, wherein at least one of the NB PRS time resources comprises an NB PRS for positioning a wireless user device; and

determine, from first radio frames of a cell and based on a plurality of repetitions of the NB PRS bitmap, first NB PRS time resources of the cell, wherein an NB PRS muting indicator indicates that the first radio frames of the cell are not muted; and

a transceiver to:

transmit, via the antenna, NB PRS configuration information comprising the NB PRS bitmap and the NB PRS muting indicator;

transmit a first NB PRS via at least one of the first NB PRS time resources of the cell; and

receive, from the wireless user device after transmitting the first NB PRS, a reference signal time difference (RSTD).

15. The base station of claim 14 , wherein the transceiver receives, from the wireless user device, a second RSTD associated with a second NB PRS of a second cell, and receives, from the wireless user device, a third RSTD associated with a third NB PRS of a third cell.

16. The base station of claim 15 , wherein the processor is configured to determine, based on the RSTD, the second RSTD, and the third RSTD, a location of the wireless user device.

17. The base station of claim 14 , wherein the NB PRS bitmap has a size of 10 consecutive bits respectively corresponding to 10 subframes in each radio frame, and

wherein each of the first NB PRS time resources corresponds to one subframe.

18. The base station of claim 14 , wherein the NB PRS bitmap has a size of 40 consecutive bits respectively corresponding to 40 subframes of four consecutive radio frames, and

wherein each of the first NB PRS time resources corresponds to one subframe.

19. The base station of claim 18 , wherein the NB PRS bitmap has a size of 40 consecutive bits respectively corresponding to 40 subframes of different four consecutive radio frames.

20. The base station of claim 14 , wherein the processor is configured to assign value ‘1’ to n-th bit of the NB PRS bitmap to designate n-th subframe of a radio frame as an NB PRS time resource.

21. The base station of claim 14 , wherein the NB PRS muting indicator has a size of k consecutive bits respectively corresponding to k consecutive radio frames, where k is an integer selected from 2, 4, 8, or 16.

22. The base station of claim 21 , wherein the processor is configured to determine, based on a value of n-th bit of the NB PRS muting indicator, muted NB PRS time resources in n-th radio frame of the k consecutive radio frames.

23. The base station of claim 14 , wherein one bit of the NB PRS muting indicator corresponds to four consecutive radio frames.