Reference signal design for NR downlink positioning: supplementary RS design
In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. The apparatus may be a UE. The apparatus may be a UE. The UE receives one or more positioning reference signal parameters from a base station. The UE determines resource elements in a transmission bandwidth carrying multiple positioning reference signals based on the positioning reference signal parameters. The UE decodes symbols in the resource elements.
1. A method of wireless communication of a user equipment (UE), comprising:
receiving one or more positioning reference signal parameters from a base station; and
determining, in a transmission bandwidth and in accordance with the one or more positioning reference signal parameters, a first part of multiple positioning reference signals transmitted on N1 consecutive symbol periods in a slot and a second part of the multiple positioning reference signals transmitted on N2 consecutive symbol periods in the slot, N1 and N2 each being an integer, wherein a location of a subcarrier carrying a positioning reference signal in a particular symbol period of the N1 symbol periods is determined as:
S
f
*
m
+
(
l
*
S
f
2
+
⌊
l
/
2
⌋
+
V
shift
)
mod
S
f
,
wherein a subcarrier spacing between two adjacent positioning reference signals in each of the N1 consecutive symbol periods are S f subcarriers, S f being an integer greater than 0, m is an integer equal to or greater than 0, l is a symbol period index of the particular symbol period in the N1 consecutive symbol periods and starts from 0, V shift is a subcarrier shift.
2. The method of claim 1 , further comprising:
receiving an indication indicating whether the multiple positioning reference signals are transmitted from one antenna port or two antenna ports at the base station; and
performing decoding based on whether the multiple positioning reference signals are transmitted from one antenna port or two antenna ports.
3. The method of claim 1 , wherein the one or more positioning reference signal parameters are configured by a higher layer, wherein the one or more positioning reference signal parameters specify a starting resource block of the transmission bandwidth and the transmission bandwidth, the method further comprising:
determining a number of consecutive resource blocks whose bandwidth constitutes the transmission bandwidth based on the one or more positioning reference signal parameters.
4. The method of claim 1 , wherein the multiple positioning reference signals are mapped to resource elements with a same starting resource block and within the transmission bandwidth in N consecutive symbol periods in the slot.
5. The method of claim 4 , wherein in the N1 consecutive symbol periods, each positioning reference signal of the first part of the multiple positioning reference signals occupies a subcarrier different from subcarriers occupied by other multiple positioning reference signals of the first part of the multiple positioning reference signals.
6. The method of claim 5 , wherein positioning reference signals in each symbol period of the N1 consecutive symbol periods are evenly distributed on subcarriers of the transmission bandwidth.
7. The method of claim 5 , wherein the N1 consecutive symbol periods correspond to respective N1 segments of the transmission bandwidth that do not overlap with each other, wherein in each of the N1 consecutive symbol periods a portion of the first part of the multiple positioning reference signals is evenly distributed on subcarriers of a respective segment of the transmission bandwidth corresponding to the each symbol period.
8. The method of claim 4 , wherein subcarriers occupied by the second part of the multiple positioning reference signals transmitted in the N2 consecutive symbol periods are a subset of subcarriers occupied by the first part of the multiple positioning reference signals transmitted in the N1 consecutive symbol periods, wherein positioning reference signals in each symbol period of the N2 consecutive symbol periods are evenly distributed on subcarriers of the transmission bandwidth.
9. The method of claim 4 , wherein subcarriers occupied by the second part of the multiple positioning reference signals transmitted in the N2 consecutive symbol periods at least partially overlap with subcarriers occupied by the first part of the multiple positioning reference signals transmitted in the N1 consecutive symbol periods, wherein a portion of the second part of the multiple positioning reference signals is evenly distributed on subcarriers of the transmission bandwidth in each of the N2 consecutive symbol periods.
10. The method of claim 4 , further comprising:
receiving a down link control channel in symbol periods of the slot other than the N consecutive symbol periods; or
determining that symbol periods in the slot other than the N consecutive symbol periods and symbol periods used for the down link control channel are not used for transmission within the transmission bandwidth.
11. The method of claim 4 , wherein (a) a sum of N1 and N2 is less than or equal to 14 and is greater than or equal to 2, (b) N1 is greater than or equal to 2, or (c) N1 is less than or equal to 12.
12. The method of claim 4 , further comprising:
determining an index of a first symbol period, from a set of predetermined symbol periods within the slot, of the N consecutive symbol periods in a transmission burst.
13. The method of claim 4 , further comprising:
determining N consecutive symbol periods in one or more second slots during which the multiple positioning reference signals are repeatedly transmitted, the one or more second slots being subsequent and consecutive to the slot;
receiving the multiple positioning reference signals in the N consecutive symbol periods in the one or more second slots; and
determining that the slot and the one or more second slots form one of a plurality of positioning reference signal transmission occasions within a transmission burst.
14. The method of claim 4 , further comprising:
determining the subcarrier spacing; and
determining a respective location of a subcarrier carrying a positioning reference signal and that is relative to a first subcarrier of the starting resource block of the transmission bandwidth in each of the N1 consecutive symbol periods, wherein N1 is greater than or equal to 1 and is less than or equal to S f , or wherein N1 is further greater than or equal to S f /2 and S f is 2, 4, 6, 8, or 12, or wherein N1 is further an integer greater than or equal to S f /2 and S f is 1 or 3.
15. The method of claim 14 , further comprising:
determining the subcarrier shift based on the positioning reference signal parameters;
determining consecutive symbol period indices of the N1 symbol periods within the slot; and
determining the location of a subcarrier carrying a positioning reference signal that is relative to the first subcarrier of the starting resource block of the transmission bandwidth in the particular symbol period of the N1 symbol periods.
16. The method of claim 14 , further comprising:
determining first consecutive symbol period indices of the N1 symbol periods;
determining second consecutive symbol period indices of the N2 symbol periods;
determining that locations of subcarriers carrying positioning reference signals that are relative to the first subcarrier of the starting resource block of the transmission bandwidth in a particular symbol period of the N2 symbol periods are the same as locations of subcarriers carrying positioning reference signals in the particular symbol period of the N1 consecutive symbol periods having a relative symbol period index of
q mod N 1
wherein q is a relative symbol period index of the particular symbol period in the N2 consecutive symbol periods and starts from 0.
17. An apparatus for wireless communication, the apparatus being a user equipment (UE), comprising:
a memory; and
at least one processor coupled to the memory and configured to:
receive one or more positioning reference signal parameters from a base station;
determine, in a transmission bandwidth and in accordance with the one or more positioning reference signal parameters, a first part of multiple positioning reference signals transmitted on N1 consecutive symbol periods in a slot and a second part of the multiple positioning reference signals transmitted on N2 consecutive symbol periods in the slot, N1 and N2 each being an integer, wherein a location of a subcarrier carrying a positioning reference signal in a particular symbol period of the N1 symbol periods is determined as:
S
f
*
m
+
(
l
*
S
f
2
+
⌊
l
/
2
⌋
+
V
shift
)
mod
S
f
,
wherein a subcarrier spacing between two adjacent positioning reference signals in each of the N1 consecutive symbol periods are S f subcarriers, S f being an integer greater than 0, m is an integer equal to or greater than 0, l is a symbol period index of the particular symbol period in the N1 consecutive symbol periods and starts from 0, V shift is a subcarrier shift.