C.3.2 Power Delay Profile (PDP)
38.1513GPPNRRelease 17TSUser Equipment (UE) Multiple Input Multiple Output (MIMO) Over-the-Air (OTA) performance requirements
This measurement checks that the resulting power delay profile (PDP) is in-line with the PDP defined for the channel model. For PDP validation measurement, only Vertical validation is required.
The PDP measurement is performed with a Vector Network Analyser (VNA). An example setup for PDP measurement is shown in Figure C.3.2-1. VNA transmits frequency sweep signals thorough the NR MIMO OTA test system. A reference antenna (i.e dipole antenna), within the centre of the test zone, receives the signal and VNA analyses the frequency response of the system. A number of traces (frequency responses) are measured and recorded by VNA and analysed by a post processing SW, e.g., Matlab. Special care has to be taken into account to keep the fading conditions unchanged, i.e. frozen, during the short period of time of a single trace measurement. The fading may proceed only in between traces.
Figure C.3.2-1: Setup for PDP measurements
Step the emulation and store traces from VNA, i.e., run the emulation to CIR number 1, pause, measure VNA trace, run the emulation to CIR number 10, pause, measure VNA trace. Continue until 1000 VNA traces are measured.
VNA settings:
Table C.3.2-1: VNA settings for PDP measurements
Item |
Unit |
Value |
Centre frequency |
MHz |
Downlink centre frequency in Table C.3.1-1 |
Span |
MHz |
200 |
Number of traces |
1000 |
|
Number of points |
1101 |
|
Averaging |
1 |
Channel model specification:
Table C.3.2-2: Channel model specification for PDP measurements
Item |
Unit |
Value |
---|---|---|
Centre frequency |
MHz |
Downlink centre frequency in Table C.3.1-1 |
Distance between traces in channel model |
wavelength (Note) |
> 2 |
Channel model |
As specified in Annex C.1 |
|
NOTE: Time [s] = distance [λ] / MS speed [λ/s] MS speed [λ/s] = MS speed [m/s] / Speed of light [m/s] * Centre frequency [Hz] |
Method of measurement result analysis:
Measured VNA traces (frequency responses H(t,f)) are saved into a hard drive. The data is read into, e.g., Matlab.
The analysis is performed by taking the Fourier transform of each FR. The resulting impulse responses h(t,) are averaged in power over time:
Finally the resulting PDP is shifted in delay, such that the first tap is on delay zero.
Beam-Specific Block Diagram
It is assumed that the beams are mapped to the inputs of the channel emulator as follows:
– Beam 1: Input 1 and Input 2
– Beam 2: Input 3 and Input 4 (CDL-C UMa only)
Figure C.3.2-2: Setup for Beam-Specific PDP measurements (Beam 1)
Figure C.3.2-3: Setup for Beam-Specific PDP measurements (Beam 2 CDL-C UMa only)
The detailed PDP reference value for CDL-C UMa and CDL-C UMi validation are defined in the following tables:
Table C.3.2-3: PDP Targets for CDL-C UMa beam 1 at ≤ 2.5 GHz
Combined Clusters index |
Delay(ns) |
Power(dB) |
1 |
0 |
-34.3 |
2-5 |
80 |
-19.5 |
6-8 |
235 |
0.0 |
9-10 |
290 |
-33.0 |
11 |
450 |
-35.8 |
12 |
480 |
-34.0 |
Table C.3.2-4: PDP Targets for CDL-C UMa beam 2 at ≤ 2.5 GHz
Combined Clusters index |
Delay(ns) |
Power(dB) |
1 |
0 |
-27.9 |
2-5 |
80 |
0.0 |
6-8 |
235 |
-18.4 |
9-10 |
290 |
-27.8 |
11 |
450 |
-27.9 |
12 |
480 |
-28.0 |
Table C.3.2-5: PDP Targets for CDL-C UMa beam 1 at > 2.5 GHz
Combined Clusters index |
Delay(ns) |
Power(dB) |
1 |
0 |
-34.2 |
2-5 |
80 |
-19.3 |
6-8 |
235 |
0.0 |
9 |
290 |
-34.7 |
10 |
450 |
-35.8 |
11 |
480 |
-34.7 |
Table C.3.2-6: PDP Targets for CDL-C UMa beam 2 at > 2.5 GHz
Combined Clusters index |
delay(ns) |
power(dB) |
1 |
0 |
-27.8 |
2-5 |
80 |
0.0 |
6-8 |
235 |
-18.3 |
9-10 |
290 |
-28.9 |
11 |
450 |
-28.1 |
12 |
480 |
-28.8 |
Table C.3.2-7: PDP Targets for CDL-C UMi at ≤ 2.5 GHz and > 2.5 GHz
Combined Clusters index |
Delay(ns) |
Power(dB) |
1 |
0 |
-30.7 |
2-5 |
20 |
-19.2 |
6-10 |
65 |
0 |
11-12 |
130 |
-31.4 |