B.4A High speed train conditions
25.1043GPPBase Station (BS) radio transmission and reception (FDD)Release 17TS
High speed train conditions are as follows:
Scenario 1: Open space
Scenario 2: Tunnel with leaky cable
Scenario 3: Tunnel for multi-antennas
The high speed train conditions for the test of the baseband performance are 2 non fading propagation channels (scenario 1 and 3) and 1 fading propagation channel (scenario 2) with one tap. For BS with Rx diversity defined in scenario 1, the Doppler shift variation is the same between anttenas.
For scenario 1 and 3, Doppler shift is given by:
(B.2)
where is the Doppler shift and
is the maximum Doppler frequency. The cosine of angle
is given by
,
(B.3)
,
(B.4)
,
(B.5)
where is the initial distance of the train from BS, and
is BS-Railway track distance, both in meters;
is the velocity of the train in m/s,
is time in seconds.
For scenario 2, Rician fading is considered where Rician factor, K is defined as the ratio between the dominant signal power and the variant of the other weaker signals.
Doppler shift and cosine angle is given by equation B.2 and B.3-B.5 respectively, where the required input parameters listed in table B.2A and the resulting Doppler shift shown in Figure B.3 and B.4 are applied for all frequency bands.
Table B.2A: Parameters for high speed train conditions
Parameter |
Value |
||
Scenario 1 |
Scenario 2 |
Scenario 3 |
|
|
1000 m |
Infinity |
300 m |
|
50 m |
– |
2 m |
K |
– |
10 dB |
– |
|
350 km/h |
300 km/h |
300 km/h |
|
1340 Hz |
1150 Hz |
1150 Hz |
NOTE1: Parameters for HST conditions in table B.2A including and Doppler shift trajectories presented on figures B.3 and B.4 were derived for Band1.
Figure B.3: Doppler shift trajectory for scenario 1
Figure B.4: Doppler shift trajectory for scenario 3