6 LMU measurement requirements
25.1113GPPLocation Measurement Unit (LMU) performance specificationRelease 17TSUser Equipment (UE) positioning in UTRAN
6.1 General
All tests at specified detection levels require that the LMU detection threshold be set such that the false alarm rate is at or below 5 % when no signal is present (noise only).
6.2 RRC States supported
UTDOA positioning technique does work in CELL_DCH and CELL_FACH state, not in URA_PCH nor CELL_PCH state.
6.3 Maximum response times
1) The maximum time for a Master LMU to establish a reference signal shall be, after the data capture has started, less than 5 seconds.
2) The maximum time for the distribution of the reference signal to another LMU involved in the positioning shall be less than 3 seconds.
3) The maximum time of detection of the time of arrival in an LMU given the reference signal shall be less than 15 seconds.
6.4 Nominal time accuracy
Nominal Time Accuracy requirement verifies the difference between the detected time of arrival and the real time of arrival.
In an AWGN environment with no fading or multi-paths, the standard deviation of the timing error of the LMU shall be less than 30 ns when the signal presence is correctly detected.
6.5 Multipath scenarios
The purpose of the test case is to verify the LMU receiver’s performance in multipath.
For the 12.2 kbps reference measurement channel specified in 3GPP TS 25.104 Annex A [1], and with Rx diversity (using both diversity paths), the LMU shall be capable of detecting the earliest path, for at least 90 % of the location attempts, at the levels in Table 5.1.
Nominal time accuracy for multipath fading scenarios includes an additional chip duration of 260 nanoseconds over that in Section 5.4.
Table 5.1: Multipath detection level
|
Propagation condition |
Detection level: Signal to Noise level in (dB) |
Note |
|
Static (AWGN) |
-51.2 dB |
NOTE 1 |
|
Multipath fading Case 1 |
-47.2dB |
NOTE 2 |
|
Multipath fading Case 2 |
– 43.8 dB |
NOTE 2 |
|
Multipath fading Case 3 |
– 41.9 dB |
NOTE 2 |
|
Multipath fading Case 4 |
– 39.8 dB |
NOTE 2 |
NOTE 1: Static propagation condition is described in 3GPP TS 25.104 Annex B.1 [1].
NOTE 2: Multipath-fading case 1-4 is described in 3GPP TS 25.104 Annex B.2 [1].
6.6 Moving scenario
The purpose of the test case is to verify the LMU receiver’s performance to Doppler shift.
In an AWGN environment with no fading or multi-paths, and at a speed of 250km/h, the detectability of the LMU shall be degraded by no more than 1.5 dB.
6.7 Cross correlation
The ability of the LMU to detect a weak terminal signal in the presence of a strong other terminal is covered in Section 5.5 when the other terminal interference is modelled as AWGN.
Annex A (informative):
Change history
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Change history |
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Date |
TSG |
Doc. |
CR |
Rev |
Subject/Comment |
Cat |
Old |
New |
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2005-08 |
Initial version created |
0.1.0 |
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2007-11 |
Incorporate simulation results and synchronize with TS.104 |
0.1.0 |
1.0.0 |
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2007-12 |
38 |
RP-071015 |
Approved version at RAN TSG # 38 |
1.0.0 |
7.0.0 |
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2008-03 |
39 |
RP-080122 |
1 |
Correcting multipath detection level in LMU performance specification |
F |
7.0.0 |
7.1.0 |
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2008-12 |
SP-42 |
Upgraded unchanged from Rel-7 |
8.0.0 |
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2009-12 |
SP-46 |
Upgraded unchanged from Rel-8 |
9.0.0 |
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SP-51 |
Upgraded unchanged from Rel-9 |
9.0.0 |
10.0.0 |
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2012-09 |
SP-57 |
– |
– |
– |
Update to Rel-11 version (MCC) |
10.0.0 |
11.0.0 |
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2014-09 |
SP-65 |
– |
– |
– |
Update to Rel-12 version (MCC) |
11.0.0 |
12.0.0 |
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2016-01 |
SP-70 |
– |
– |
– |
Update to Rel-13 version (MCC) |
12.0.0 |
13.0.0 |
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2017-03 |
RP-75 |
– |
– |
– |
Update to Rel-14 version (MCC) |
13.0.0 |
14.0.0 |
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Change history |
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Date |
Meeting |
TDoc |
CR |
Rev |
Cat |
Subject/Comment |
New version |
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2018-06 |
SA#80 |
– |
– |
– |
– |
Update to Rel-15 version (MCC) |
15.0.0 |
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2020-06 |
SA#88 |
– |
– |
– |
– |
Update to Rel-16 version (MCC) |
16.0.0 |
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2022-03 |
SA#95 |
Update to Rel-17 version (MCC) |
17.0.0 |
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