E.1 General
37.5443GPPConformance testingRelease 16TSUniversal Terrestrial Radio Access (UTRA) and Evolved UTRA (E-UTRA)User Equipment (UE) Over The Air (OTA) performance
- Individual uncertainty contributions in the TRP and TRS measurements are discussed and evaluated in this Annex. A technique for calculating the total measurement uncertainty is also presented.
- An important part of a standard measurement procedure is the identification of uncertainty sources and the evaluation of the overall measurement uncertainty. There are various individual uncertainty sources in the measurement procedure that introduce a certain uncertainty contribution to the final measurement result. The approach in this standard test procedure is that the test laboratories are not limited to using some specific instruments and antenna positioners, for example. However, a limit is set for the maximum overall measurement uncertainty.
- The TRP/TRS measurement procedure can be considered to include two stages. In Stage 1 the actual measurement of the 3-D pattern of the Device Under Test (DUT) is performed. In Stage 2 the calibration of the absolute level of the DUT measurement results is performed by means of using a calibration antenna whose absolute gain/radiation efficiency is known at the frequencies of interest. The uncertainty contributions related to TRP are listed in Tables E.1-1 and E.1-2 and the contributions related to TRS are in Tables E.1-3 and E.1-4. The uncertainty contributions are analyzed in the following paragraphs.
- The calculation of the uncertainty contribution is based on the ISO Guide to the expression of uncertainty in measurement. Each individual uncertainty is expressed by its Standard Deviation (termed here as ‘standard uncertainty’) and represented by symbol U. The uncertainty contributions can be classified to two categories: Type-A uncertainties, which are statistically determined e.g. by repeated measurements, and Type-B uncertainties, which are derived from existing data e.g. data sheets. Several individual uncertainties are common in Stage 1 and Stage 2 and therefore cancel.
- The procedure of forming the uncertainty budget in TRP measurement is:
-
- 1) Compile lists of individual uncertainty contributions for TRP measurement in both Stage 1 and Stage 2.
-
- 2) Determine the standard uncertainty of each contribution by
- a) Determining the distribution of the uncertainty (Gaussian, U-shaped, rectangular, etc.)
- b) Determining the maximum value of each uncertainty (unless the distributions is Gaussian)
- c) Calculating the standard uncertainty by dividing the uncertainty by
if the distribution is U-shaped, and by 
if the distribution is rectangular. - 3) Convert the units into decibel, if necessary.
- 4) Combine all the standard uncertainties by the Root of the Sum of the Squares (RSS) method.
- 5) Combine the total uncertainties in Stage 1 and Stage 2 also by the RSS method:
. - 6) Multiply the result by an expansion factor of 1.96 to derive expanded uncertainty at 95% confidence level: 1.96 *
. - Example uncertainty budgets are presented in Tables E.29-1, E.29-2, E.29-3, E.29-4, E.29-5, E.29-6, E.29-7, E.29-8, E.29.9, and E.29-10.
- Table E.1-1: Uncertainty contributions in TRP measurement for anechoic chamber method
|
Description of uncertainty contribution |
Details in paragraph |
|
Stage 1, DUT measurement |
|
|
1) Mismatch of receiver chain (i.e. between probe antenna and measurement receiver) |
E.2-E.3 |
|
2) Insertion loss of receiver chain |
E.4-E.6 |
|
3) Influence of the probe antenna cable |
E.7 |
|
4) Uncertainty of the absolute antenna gain of the probe antenna |
E.8 |
|
5) Measurement Receiver: uncertainty of the absolute level |
E.9 |
|
6) Measurement distance: a) offset of DUT phase centre from axis(es) of rotation b) mutual coupling between the DUT and the probe antenna c) phase curvature across the DUT |
E.10 |
|
7) Quality of quiet zone |
E.11 |
|
8) DUT Tx-power drift |
E.12 |
|
9) Uncertainty related to the use of phantoms: (applicable when a phantom is used): If SAM head phantom is used: a) uncertainty from using different types of SAM phantom b) simulated tissue liquid uncertainty If SAM head and hand phantoms are used: a) uncertainty from using different types of SAM phantom b) simulated tissue liquid uncertainty c) uncertainty of dielectric properties and shape of the hand phantom If a hand phantom is used: a) uncertainty of dielectric properties and shape of the hand phantom If a laptop ground plane phantom is used: a) Uncertainty related to the use of the Laptop Ground Plane phantom |
E.13 |
|
10) Coarse sampling grid |
E.14 |
|
11 ) Random uncertainty (repeatability, including positioning uncertainty of the DUT against the SAM phantom or DUT plugged into the Laptop Ground Plane phantom) |
E.15 |
|
Stage 2 , Calibration measurement, network analyzer method, figure B.2.1-1 |
|
|
13) Uncertainty of network analyzer |
E.16 |
|
14) Mismatch of receiver chain |
E.2-E.3 |
|
15) Insertion loss of receiver chain |
E.4-E.6 |
|
16) Mismatch in the connection of calibration antenna |
E.2 |
|
17) Influence of the calibration antenna feed cable |
E.7 |
|
18) Influence of the probe antenna cable |
E.7 |
|
19) Uncertainty of the absolute gain of the probe antenna |
E.8 |
|
20) Uncertainty of the absolute gain/ radiation efficiency of the calibration antenna |
E.17 |
|
21)Measurement distance: a) Offset of calibration antenna’s phase centre from axis(es) of rotation b) Mutual coupling between the calibration antenna and the probe antenna c) Phase curvature across the calibration antenna |
E.10 |
|
22) Quality of quiet zone |
E.11 |
- Table E.1-2: Uncertainty contributions in Uncertainty contributions in TRP measurement for reverberation chamber method
|
Description of uncertainty contribution |
Details in paragraph |
|
Stage 1, DUT measurement |
|
|
1) Mismatch of receiver chain (i.e. between fixed measurement antenna and measurement receiver) |
E.2-E.3 |
|
2) Insertion loss of receiver chain |
E.4-E.6 |
|
3) Influence of the fixed measurement antenna cable |
E.7 |
|
4) Uncertainty of the absolute antenna gain of the fixed measurement antenna |
E.8 |
|
5) Measurement Receiver: uncertainty of the absolute level |
E.9 |
|
6) Chamber statistical ripple and repeatability |
E.28 |
|
7) Additional power loss in EUT chassis |
E.29 |
|
8) DUT Tx-power drift |
E12 |
|
9) Uncertainty related to the use of phantoms: (applicable when a phantom is used): If SAM head phantom is used: a) uncertainty from using different types of SAM phantom b) simulated tissue liquid uncertainty If SAM head and hand phantoms are used: a) uncertainty from using different types of SAM phantom b) simulated tissue liquid uncertainty c) uncertainty of dielectric properties and shape of the hand phantom If a hand phantom is used: a) uncertainty of dielectric properties and shape of the hand phantom If a laptop ground plane phantom is used: a) Uncertainty related to the use of the Laptop Ground Plane phantom |
E.13 |
|
10) Independent samples |
E.14 |
|
11) Random uncertainty (repeatability, including positioning uncertainty of the DUT against the SAM phantom or DUT plugged into the Laptop Ground Plane phantom) |
E.15 |
|
Stage 2 , Calibration measurement, network analyzer method, figure B.2.2-1 |
|
|
12) Uncertainty of network analyzer |
E.16 |
|
13) Mismatch of receiver chain |
E.2-E.3 |
|
14) Insertion loss of receiver chain |
E.4-E.6 |
|
15) Mismatch in the connection of calibration antenna |
E.2 |
|
16) Influence of the calibration antenna feed cable |
E.7 |
|
17) Influence of the fixed measurement antenna cable |
E.7 |
|
18) Uncertainty of the absolute gain of the fixed measurement antenna |
E.8 |
|
19) Uncertainty of the absolute gain/ radiation efficiency of the calibration antenna |
E.17 |
|
20) Chamber statistical ripple and repeatability |
E.28 |
- Table E.1-3: Uncertainty contributions in TRS measurement for anechoic chamber method
|
Description of uncertainty contribution |
Details in paragraph |
|
Stage 1, DUT measurement |
|
|
1) Mismatch of transmitter chain (i.e. between probe antenna and base station simulator) |
E.2-E.3 |
|
2) Insertion loss of transmitter chain |
E.4-E.6 |
|
3) Influence of the probe antenna cable |
E.7 |
|
4) Uncertainty of the absolute antenna gain of the probe antenna |
E.8 |
|
5) Base station simulator: uncertainty of the absolute output level |
E.18 |
|
6) BER measurement: output level step resolution |
E.19 |
|
7) Statistical uncertainty of BER measurement |
E.20 |
|
8) BER data rate normalization |
E.21 |
|
9) Measurement distance: a) offset of DUT phase centre from axis(es) of rotation b) mutual coupling between the DUT and the probe antenna c) phase curvature across the DUT |
E.10 |
|
10) Quality of quiet zone |
E.11 |
|
11) DUT sensitivity drift |
E.22 |
|
12) Uncertainty related to the use of phantoms: (applicable when a phantom is used): If SAM head phantom is used: a) uncertainty from using different types of SAM phantom b) simulated tissue liquid uncertainty If SAM head and hand phantoms are used: a) uncertainty from using different types of SAM phantom b) simulated tissue liquid uncertainty c) uncertainty of dielectric properties and shape of the hand phantom If a hand phantom is used: a) uncertainty of dielectric properties and shape of the hand phantom If a laptop ground plane phantom is used: a) Uncertainty related to the use of the Laptop Ground Plane phantom |
E.13 |
|
13) Coarse sampling grid |
E.14 |
|
14 ) Random uncertainty (repeatability) -positioning uncertainty of the DUT against the SAM or DUT plugged into the Laptop Ground Plane phantom |
E.15 |
|
Stage 2 , Calibration measurement, network analyzer method, figure B.2.1-1 |
|
|
16) Uncertainty of network analyzer |
E.16 |
|
17) Mismatch in the connection of transmitter chain (i.e. between probe antenna and NA) |
E.2-E.3 |
|
18) Insertion loss of transmitter chain |
E.4-E.6 |
|
19) Mismatch in the connection of calibration antenna |
E.2 |
|
20) Influence of the calibration antenna feed cable |
E.7 |
|
21) Influence of the probe antenna cable |
E.7 |
|
22) Uncertainty of the absolute gain of the probe antenna |
E.8 |
|
23) Uncertainty of the absolute gain/radiation efficiency of the calibration antenna |
E.17 |
|
24)Measurement distance: a) Offset of calibration antenna’s phase centre from axis(es) of rotation b) Mutual coupling between the calibration antenna and the probe antenna c) Phase curvature across the calibration antenna |
E.10 |
|
25) Quality of quiet zone |
E.11 |
- Table E.1-4: Uncertainty contributions in Uncertainty contributions in TRS measurement for reverberation chamber method
|
Description of uncertainty contribution |
Details in paragraph |
|
Stage 1, DUT measurement |
|
|
1) Mismatch of transmitter chain (i.e. between fixed measurement antenna and base station simulator) |
E.2-E.3 |
|
2) Insertion loss of transmitter chain |
E.4-E.6 |
|
3) Influence of the fixed measurement antenna cable |
E.7 |
|
4) Uncertainty of the absolute antenna gain of the fixed measurement antenna |
E.8 |
|
5) Base station simulator: uncertainty of the absolute output level |
E.18 |
|
6) BER measurement: output level step resolution |
E.19 |
|
7) Statistical uncertainty of BER measurement |
E.20 |
|
8) BER data rate normalization |
E.21 |
|
9) Chamber statistical ripple and repeatability |
E.28 |
|
10) Additional power loss in EUT chassis |
E.29 |
|
11) DUT sensitivity drift |
E.22 |
|
12) Uncertainty related to the use of phantoms: (applicable when a phantom is used): If SAM head phantom is used: a) uncertainty from using different types of SAM phantom b) simulated tissue liquid uncertainty If SAM head and hand phantoms are used: a) uncertainty from using different types of SAM phantom b) simulated tissue liquid uncertainty c) uncertainty of dielectric properties and shape of the hand phantom If a hand phantom is used: a) uncertainty of dielectric properties and shape of the hand phantom If a laptop ground plane phantom is used: a) Uncertainty related to the use of the Laptop Ground Plane phantom |
E.13 |
|
14) Independent samples |
E.14 |
|
13) Random uncertainty (repeatability) – positioning uncertainty of the DUT against the SAM or DUT plugged into the Laptop Ground Plane phantom |
E.15 |
|
Stage 2 , Calibration measurement, network analyzer method, figure B.2.2-1 |
|
|
15) Uncertainty of network analyzer |
E.16 |
|
16) Mismatch of receiver chain |
E.2-E.3 |
|
17) Insertion loss of receiver chain |
E.4-E.6 |
|
18) Mismatch in the connection of calibration antenna |
E.2 |
|
19) Influence of the calibration antenna feed cable |
E.7 |
|
20) Influence of the fixed measurement antenna cable |
E.7 |
|
21) Uncertainty of the absolute gain of the fixed measurement antenna |
E.8 |
|
22) Uncertainty of the absolute gain/ radiation efficiency of the calibration antenna |
E.17 |
|
23) Chamber statistical ripple and repeatability |
E.28 |