Methods and nodes for managing RSTD reports

Patent metadata

Field	Value
Publication number	US-10045324-B2
Application number	US-201615510782-A
Country	US
Kind code	B2
Filing date	Mar 3, 2016
Priority date	May 15, 2015
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

The disclosed embodiments herein relate to a method performed by a UE; a UE, a method performed by a location server and a location server and computer programs respectively. The method performed by the UE comprises: receiving from a location server NetWork assisted Reference Signal Time Difference, RSTD, Quantization Information, NW-QI; performing RSTD measurements by measuring or estimating a Time Of Arrival, TOA, of a Positioning Reference Signal, PRS, from respective base station of a plurality of base stations; encoding the RSTD measurements by employing a Enhanced RSTD Quantization Method, E-QM, or by using the NW-QI while encoding the RSTD measurements; and sending UE assisted RSTD Quantization Information, UE-QI, to the location server, the UE-QI including the encoded RSTD measurements.

First claim

The invention claimed is:

1. A method performed by a user equipment, UE, the method comprising:
performing Reference Signal Time Difference, RSTD, measurements by estimating or measuring a Time Of Arrival, TOA, of a Positioning Reference Signal, PRS, from respective base station of a plurality of base stations;
encoding the RSTD measurements by employing an Enhanced RSTD Quantization Method, E-QM, having optimizable quantization, or by using NetWork Assisted RSTD Quantization Information, NW-QI, comprising information for performing enhanced quantization, received from a location server, while encoding the RSTD measurements; and
sending UE assisted RSTD Quantization Information, UE-QI, comprising additional information for decoding of the encoded RSTD measurements, to the location server, the UE-QI including the encoded RSTD measurements.

2. The method according to claim 1 wherein employing the E-QM method comprises transforming the RSTD measurements, grouping the RSTD measurements, and employing a quantization function for each RSTD measurement group.

3. The method according to claim 2 wherein transforming comprises subtracting a constant offset value from the RSTD measurements in order to reduce the absolute values of the RSTD measurements.

4. The method according to claim 2 wherein grouping the RSTD measurements comprises identifying a group of RSTD measurements having RSTD measurements values above a threshold value and identifying another group having RSTD measurements values below the threshold value.

5. The method according to claim 2 wherein the quantization function for each RSTD measurement group comprises linearly quantizing the measurements while using a quantization resolution and wherein the quantization resolution refers to the number of bits used for representing the quantized measurements.

6. The method according to claim 1 further comprising estimating a position of the UE based on the UE-QI including the encoded RSTD measurements.

7. A method performed by a location server, the method comprising:
at least one from the group of:
transmitting NetWork assisted Reference Signal Time Difference, RSTD, Quantization Information, NW-QI, comprising information for performing enhanced quantization, to a User Equipment, UE; and
receiving UE assisted RSTD Quantization Information, UE-QI, comprising additional information for decoding of encoded RSTD measurements, from the UE, including encoded RSTD measurements and further receiving RSTD measurements quality assessment report from the UE;

decoding the RSTD quantized measurements using the UE-QI and/or the NW-QI; and
estimating a position of the UE based on the decoded RSTD quantized measurements.

8. The method according to claim 7 further comprising requesting capabilities of the UE prior to receiving UE-QI from the UE.

9. A user equipment, UE, comprising a processor and a memory, said memory containing instructions executable by said processor whereby said UE is operative to:
perform Reference Signal Time Difference, RSTD, measurements by measuring or estimating a Time Of Arrival, TOA, of a Positioning Reference Signal, PRS, from respective base station of a plurality of base stations;
encode the RSTD measurements by employing a Enhanced RSTD Quantization Method, E-QM, having optimizable quantization, or by using NetWork assisted RSTD Quantization Information, NW-QI, comprising information for performing enhanced quantization, received from a location server, while encoding the RSTD measurements; and
send UE assisted RSTD Quantization Information, UE-QI, comprising additional information for decoding of the encoded RSTD measurements, to the location server, the UE-QI including the encoded RSTD measurements.

10. The UE according to claim 9 being operative to employ the E-QM method by transforming the RSTD measurements, grouping the RSTD measurements, and employing a quantization function for each RSTD measurement group.

11. The UE according to claim 10 being operative to transform the RSTD measurements by subtracting a constant offset value from the RSTD measurements in order to reduce the absolute values of the RSTD measurements.

12. The UE according to claim 10 being operative to group the RSTD measurements by identifying a group of RSTD measurements having RSTD measurements values above a threshold value and identifying another group having RSTD measurements values below the threshold value.

13. The UE according to claim 10 being operative to employ a quantization function for each RSTD measurement group, wherein the quantization function for each RSTD measurement group comprises linearly quantizing the measurements while using a quantization resolution and wherein the quantization resolution refers to the number of bits used for representing the quantized measurements.

14. The UE according to claim 9 being further operative to estimate a position of the UE based on the UE-QI including the encoded RSTD measurements.

15. A method performed by a location server comprising:
at least one from the group of:
transmitting NetWork assisted Reference Signal Time Difference, RSTD, Quantization Information, NW-QI, comprising information for performing enhanced quantization, to a User Equipment, UE; and
receiving UE assisted RSTD Quantization Information, UE-QI, comprising additional information for decoding of encoded RSTD measurements, from the UE, including encoded RSTD measurements and further receiving RSTD measurements quality assessment report from the UE;

decoding the RSTD quantized measurements using the UE-QI and/or the NW-QI; and
estimating position of the UE based on the decoded RSTD quantized measurements.

16. The method according to claim 15 further comprising requesting capabilities of the UE prior to receiving UE-QI from the UE.

17. A location server comprising a processor and a memory, said memory containing instructions executable by said processor whereby said location server is operative to:
at least one from the group of:
transmit NetWork assisted Reference Signal Time Difference, RSTD, Quantization Information, NW-QI, comprising information for performing enhanced quantization, to a User Equipment, UE; and
receive UE assisted RSTD Quantization Information, UE-QI, comprising additional information for decoding of encoded RSTD measurements, from the UE, including encoded RSTD measurements and further receiving RSTD measurements quality assessment report from the UE;

decode the RSTD quantized measurements using the UE-QI and/or the NW-QI; and
estimate a position of the UE based on the decoded RSTD quantized measurements.

18. The location server according to claim 17 is further operative to request capabilities of the UE prior to receiving UE-QI from the UE.

19. The method of claim 1 wherein the UE-QI comprises an indication of at least one from the group of: a transformation; a grouping; a quantization choice; a range for which an approximation function is valid; a coefficient of a polynomial function; and a range or interval of quantized values.

20. The method of claim 7 wherein the UE-QI comprises an indication of at least one from the group of: a transformation; a grouping; a quantization choice; a range for which an approximation function is valid; a coefficient of a polynomial function; and a range or interval of quantized values.

21. The UE of claim 9 wherein the UE-QI comprises an indication of at least one from the group of: a transformation; a grouping; a quantization choice; a range fo

Assignees

• Ericsson Telefon Ab L M

Inventors

• Zaidi Ali
• Modarres Razavi Sara
• Gunnarsson Fredrik
• Wang Meng
• Blankenship Yufei
• Rydén Henrik

Classifications

• G01S5/0036

  of measured values, i.e. measurement on mobile and position calculation on base station · CPC title

• G01S5/0236

  Assistance data, e.g. base station almanac · CPC title

• H04W84/042

  Public Land Mobile systems, e.g. cellular systems · CPC title

• H04W64/00 Primary

  Locating users or terminals {or network equipment} for network management purposes, e.g. mobility management · CPC title

• G01S5/10

  Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements {, e.g. omega or decca systems}(G01S5/12 takes precedence {; beacons and receivers cooperating therewith G01S1/306, G01S1/308}) · CPC title