yigid/openairinterface5g
1
0
Fork 0
mirror of https://gitlab.eurecom.fr/oai/openairinterface5g.git synced 2026-07-13 04:30:28 +00:00
Code Issues Packages Projects Releases Wiki Activity

Add documentation on multiple NR UE RF-frontends to RUNMODEM.md

Browse Source
This commit is contained in:
Thomas Schlichter
2025-09-01 14:51:07 +00:00
parent 3435fcc010
commit a91838937f
1 changed files with 98 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

98
doc/RUNMODEM.md
View File

@@ -140,6 +140,104 @@ You can view all available options by typing:
```shell
./nr-uesoftmodem --help
```
### NR UE: Configure multiple RF-frontends (RUs)
Multiple RF-frontends (also called RUs) can be defined for the nr-uesoftmodem.
Therefore, two sections in the NR UE configuration file are used:
- `RUs`
- `cells`
The `RUs` section in the NR UE configuration file contains an array of elements, where each element has these properies:
| Property name | Type | Default value | Description |
| ---------------- | -------------- | ------------- | ------------------------------------ |
| nb_tx | integer | 1 | Number of TX Antennas |
| nb_rx | integer | 1 | Number of RX Antennas |
| att_tx | integer | 0 | TX Attenuation in dB |
| att_rx | integer | 0 | RX Attenuation in dB |
| max_rxgain | integer | 120 | Maximum RX Gain at 0 dB Attenuation |
| sdr_addrs | string | type=b200 | SDR Parameter String |
| tx_subdev | string | | SDR TX Subdevice |
| rx_subdev | string | | SDR RX Subdevice |
| clock_src | string | internal | SDR Clock Source |
| time_src | string | internal | SDR Time Source |
| tune_offset | floating point | 0.0 | SDR Tune Offset in Hz |
| if_freq | integer | 0 | DL Intermediate Frequency in Hz |
| if_offset | integer | 0 | UL Intermediate Frequency Offset in Hz |
The `cells` section in the NR UE configuration file contains an array of elements, where each element has these properies:
| Property name | Type | Default value | Description |
| ---------------- | ------- | ------------- | ---------------------------------------- |
| ru_id | integer | 0 | ID of the associated RU from the `RUs` section |
| band | integer | 78 | 5G NR Band |
| rf_freq | integer | 0 | DL Carrier Centre Frequency in Hz |
| rf_offset | integer | 0 | DL Carrier Centre Frequency Offset in Hz |
| numerology | integer | 1 | 5G NR Numerology (µ) |
| N_RB_DL | integer | 106 | Number of DL Carrier Ressource Blocks |
| ssb_start | integer | 516 | Ressource Element where the SSB Starts |
There are different scenarios where multiple RF-frontends (also called RUs) are beneficial for the NR UE:
1. RF-Simulator Inter-Frequency Handover between multiple cells
2. Multiple UEs in one instance, each using their own RF-frontend (RF-Simulator connection)
3. Different Antennas connected to different RF-ports
4. Concurrent connection to multiple carriers (carrier aggregation CA)
This would be and example configuration for the 1. scenario:
```
rfsimulator = (
{
serveraddr = "127.0.0.2";
serverport = 4043;
}, {
serveraddr = "127.0.0.3";
serverport = 4044;
}
);
RUs = (
{
nb_tx = 1;
nb_rx = 1;
}, {
nb_tx = 1;
nb_rx = 1;
}
);
cells = (
{
ru_id = 0;
band = 78;
rf_freq = 3619200000L;
numerology = 1;
N_RB_DL = 106;
ssb_start = 516;
}, {
ru_id = 1;
band = 78;
rf_freq = 3649440000L;
numerology = 1;
N_RB_DL = 106;
ssb_start = 516;
}
);
```
An example for the 2. scenario can be found in the file [ci-scripts/yaml_files/5g_rfsimulator_multiue/nrue.uicc.conf](../ci-scripts/yaml_files/5g_rfsimulator_multiue/nrue.uicc.conf).
The 3. scenario is similar to 1., but instead of providing RF-Simulator parameters, actual SDR parameters have to be provided.
The 4. scenario is not supported, as the NR UE does not implement CA, yet.
Current Limitations:
- Each RU can be used by only one cell.
- Each RU and cell can be used by only one UE (no RU sharing implemented, yet).
- The sampling rates of all RUs must be the same.
### Common gNB and NR UE command line options
#### Three-quarter sampling