C.2 Multi-path case
25.1733GPPRelease 17Requirements for support of Assisted Galileo and Additional Navigation Satellite Systems (A-GANSS) Time Division Duplex (TDD)TS
Doppler frequency difference between direct and reflected signal paths is applied to the carrier and code frequencies. The Carrier and Code Doppler frequencies of LOS and multi-path for GANSS signals are defined in table C.2-1.
Table C.2-1: Multipath case
|
Initial Relative Delay |
Carrier Doppler frequency of tap [Hz] |
Code Doppler frequency of tap [Hz] |
Relative mean Power [dB] |
|
0 |
Fd |
Fd / N |
0 |
|
X |
Fd-0.1 |
(Fd-0.1) /N |
Y |
|
Note: Discrete Doppler frequency is used for each tap. |
|||
Where the X and Y depends on the GNSS signal type and is shown in table C.2-2, and N is the ratio between the transmitted carrier frequency of the signals and the transmitted chip rate as shown in table C.2-3 (where k in table C.2-3 is the GLONASS frequency channel number).
Table C.2-2: Relative Delay and Attenuation of Non Line of Sight Signals
|
System |
Signals |
X [m] |
Y [dB] |
|
Galileo |
E1 |
125 |
-4.5 |
|
E5a |
15 |
-6 |
|
|
E5b |
15 |
-6 |
|
|
GPS/Modernized GPS |
L1 C/A |
150 |
-6 |
|
L1C |
125 |
-4.5 |
|
|
L2C |
150 |
-6 |
|
|
L5 |
15 |
-6 |
|
|
GLONASS |
G1 |
275 |
-12.5 |
|
G2 |
275 |
-12.5 |
|
|
BDS |
B1I |
75 |
-4.5 |
Table C.2-3: Ratio between the transmitted carrier frequency of the signals and the transmitted chip rate
|
System |
Signals |
N |
|
Galileo |
E1 |
1540 |
|
E5a |
115 |
|
|
E5b |
118 |
|
|
GPS/Modernized GPS |
L1 C/A |
1540 |
|
L1C |
1540 |
|
|
L2C |
1200 |
|
|
L5 |
115 |
|
|
GLONASS |
G1 |
3135.03 + k 1.10 |
|
G2 |
2438.36 + k 0.86 |
|
|
BDS |
B1I |
763 |
The initial carrier phase difference between taps shall be randomly selected between 0 and 2. The initial value shall have uniform random distribution.
Annex D (normative): Measurement sequence chart