Defining RSTD report resolution and accuracy for RSTD-based 5G NR positioning
An apparatus for use in a UE includes processing circuitry coupled to a memory. To configure the UE for Reference Signal Time Difference (RSTD)-based 5G-NR positioning. The processing circuitry is to determine a first PRS BW associated with a first PRS received from a first gNB associated with a first cell. A second PRS BW is determined, which is associated with a second PRS received from a second gNB of a second cell. An RSTD report resolution is determined based on the first PRS BW and the second PRS BW. A receive (Rx) timing difference between the first cell and the second cell is measured based on reception times of the first PRS and the second PRS. The measured Rx timing difference is mapped into an RSTD report for transmission to the first gNB, based on the RSTD report resolution.
1. An apparatus to be used in a user equipment (UE), the apparatus comprising:
processing circuitry, wherein to configure the UE for reporting on Reference Signal Time Difference (RSTD)-based 5G-New Radio (NR) positioning, the processing circuitry is to:
determine a first positioning reference signal (PRS) bandwidth (BW) associated with a first PRS received from a first Next Generation Node-B (gNB), the first gNB associated with a first cell;
determine a second PRS BW associated with a second PRS received from a second gNB, the second gNB associated with a second cell;
determine an RSTD report resolution based on the first PRS BW and the second PRS BW;
measure a receive (Rx) timing difference between the first cell and the second cell based on reception times of the first PRS and the second PRS; and
map the measured Rx timing difference into an RSTD report for transmission to the first gNB, based on the RSTD report resolution; and
a memory coupled to the processing circuitry and configured to store the first PRS BW and the second PRS BW.
2. The apparatus of claim 1 , wherein the processing circuitry is to:
determine the RSTD report resolution based on a minimal PRS BW selected from the first PRS BW and the second PRS BW.
3. The apparatus of claim 2 , wherein the processing circuitry is to:
determine the RSTD report resolution to be one of a reference timing unit (Ts) or a multiple of a minimal timing unit (Tc) based on a comparison of the minimal PRS BW with a pre-configured threshold value.
4. The apparatus of claim 3 , wherein T s =1/(Δf ref ·N f,ref )=32.5 ns, and wherein Δf ref =15·10 3 Hz and N f,ref =2048.
5. The apparatus of claim 3 , wherein T c =1/(Δf max ·N f )=0.5 ns, and wherein Δf max =480·10 3 Hz and N f =4096.
6. The apparatus of claim 2 , wherein the processing circuitry is to:
determine the RSTD report resolution as
(
400
MHz
BW
P
R
S
)
·
T
c
2
,
wherein T c =0.5 ns, and wherein BW PRS is selected based on the minimal PRS BW.
7. The apparatus of claim 6 , wherein the BW PRS is a bandwidth selected from a set of [5, 10, 20, 25, 40, 50, 80, 100, 200, 400] MHz and is closest to the minimal PRS BW.
8. The apparatus of claim 2 , wherein the processing circuitry is to:
determine the RSTD report resolution as
(
400
MHz
B
W
P
R
S
)
·
T
c
,
wherein T c =0.5 ns and BW PRS is selected based on the minimal PRS BW.
9. The apparatus of claim 8 , wherein the BW PRS is a bandwidth selected from a set of [5, 10, 20, 25, 40, 50, 80, 100, 200, 400] MHz and is closest to the minimal PRS BW.
10. The apparatus of claim 1 , further comprising transceiver circuitry coupled to the processing circuitry; and, one or more antennas coupled to the transceiver circuitry.
11. A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of a user equipment (UE), the instructions to configure the UE for Reference Signal Time Difference (RSTD)-based 5G-New Radio (NR) positioning, and to cause the UE to:
determine a first positioning reference signal (PRS) bandwidth (BW) associated with a first PRS received from a first Next Generation Node-B (gNB), the first gNB associated with a first cell;
determine a second PRS BW associated with a second PRS received from a second gNB, the second gNB associated with a second cell;
determine an RSTD report resolution based on the first PRS BW and the second PRS BW;
measure a receive (Rx) timing difference between the first cell and the second cell based on reception times of the first PRS and the second PRS; and
map the measured Rx timing difference into an RSTD report for transmission to the first gNB, based on the RSTD report resolution.
12. The computer-readable storage medium of claim 11 , wherein executing the instructions further configures the UE to:
determine the RSTD report resolution based on a minimal PRS BW selected from the first PRS BW and the second PRS BW.
13. The computer-readable storage medium of claim 12 , wherein executing the instructions further configures the UE to:
determine the RSTD report resolution to be one of a reference timing unit (Ts) or a multiple of a minimal timing unit (Tc) based on a comparison of the minimal PRS BW with a pre-configured threshold value.
14. The computer-readable storage medium of claim 13 , wherein T s =1/(Δf ref ·N f,ref )=32.5 ns, and wherein Δf ref =15·10 3 Hz and N f,ref =2048.
15. The computer-readable storage medium of claim 13 , wherein T c =1/(Δf max ·N f )=0.5 ns, and wherein Δf max =480·10 3 Hz and N f =4096.
16. The computer-readable storage medium of claim 12 , wherein executing the instructions further configures the UE to:
determine the RSTD report resolution as
(
400
MHz
BW
P
R
S
)
·
T
c
2
,
wherein T c =0.5 ns, and wherein BW PRS is selected based on the minimal PRS BW.
17. The computer-readable storage medium of claim 16 , wherein the BW PRS is a bandwidth selected from a set of [5, 10, 20, 25, 40, 50, 80, 100, 200, 400] MHz and is closest to the minimal PRS BW.
18. The computer-readable storage medium of claim 12 , wherein executing the instructions further configures the UE to:
determine the RSTD report resolution as
(
400
MHz
B
W
P
R
S
)
·
T
c
,
wherein T c =0.5 ns and BW PRS is the selected based on the minimal PRS BW, wherein the BW PRS is a bandwidth selected from a set of [5, 10, 20, 25, 40, 50, 80, 100, 200, 400] MHz and is closest to the minimal PRS BW.