diff --git a/radio/USRP/README.md b/radio/USRP/README.md index b89cabe6495e4ad541fb51e29580f80f2c4bd767..c1c555828c34d14c795aa7df311bc0aecfc1d8c5 100644 --- a/radio/USRP/README.md +++ b/radio/USRP/README.md @@ -39,11 +39,38 @@ Note 2: when using multiple USRPs they always have to be synchronized using "ext Last but not least you may specify that only a specfic subdevice of the USRP is used. See also https://files.ettus.com/manual/page_configuration.html#config_subdev -For example on a USRP N310 the following fields will specify that you use channel 0 of subdevice A. +For example on a USRP N310 the following fields will specify that you use channel 0 of subdevice A. You can enter this information after providing the ip addresses of the USRPs in sdr_addrs. ```bash tx_subdev = "A:0" rx_subdev = "A:0" ``` +Here is an example of the RUs configuration for a setup with 2 USRP N310. -When combining this with the multi USRP feature you can easily create a distributed antenna array with only 1 channel used at each USRP. +```bash +RUs = ( +{ + local_rf = "yes" + nb_tx = 2 + nb_rx = 2 + att_tx = 0 + att_rx = 0; + bands = [78]; + max_pdschReferenceSignalPower = -27; + max_rxgain = 75; + eNB_instances = [0]; + ##beamforming 1x2 matrix: 1 layer x 2 antennas + bf_weights = [0x00007fff, 0x0000]; + sdr_addrs = "addr0=192.168.10.2,addr1=192.168.20.2,clock_source=external,time_source=external" + tx_subdev ="A:0 B:0" + rx_subdev ="A:1 B:1" +} +); +``` +Hint: + +You cannot see TX/RX spread over multiple USRPs, if you use "internal" as a refrence of the clock and time source. + +Furthur information about synchronization on the USRP N3xx devices can be found here: https://kb.ettus.com/Using_Ethernet-Based_Synchronization_on_the_USRP%E2%84%A2_N3xx_Devices + +When combining this with the multi USRP feature you can create a distributed antenna array with only 1 channel used at each USRP.