Merge remote-tracking branch 'origin/multi_usrp' into integration_2023_w10b

radio/USRP/README.md

@@ -0,0 +1,36 @@
+USRP device documentation
+
+OAI works with the most common USRP models like, B200, B200mini, B210, X310, N300, N310, N320, X410. This is achieved by using the Ettus Universal Hardware Driver (UHD) (https://github.com/EttusResearch/uhd). The file usrp_lib.cpp provides an abstraction layer of UHD to OAI.
+
+The USRP can be configured in the RU section of the config file. The field "sdr_addrs" uses the same syntax as the USRP device identification string (https://files.ettus.com/manual/page_identification.html). Here are a few examples
+
+sdr_addrs = "addr=192.168.10.2" # uses a single 10Gb Ethernet interface on an N3x0 or X3x0 or X4x0
+
+sdr_addrs = "addr=192.168.10.2,second_addr=192.168.20.2" # uses 2 10Gb Ethernet interfaces on a N3x0 or X3x0 or X4x0 (requires that you flashed the FPGA wth the XG image)
+
+you can also use the multi USRP feature and specify multiple USRPs, in which case you will get the aggregated number of channels on all the devices
+
+sdr_addrs = "addr0=192.168.10.2,addr1=192.168.30.2"
+
+You can specify if you want to use external or interal clock or time source either by adding the parameters in the sdr_addrs field or by using the fields clock_src or time_src
+
+sdr_addrs = "addr=192.168.10.2,clock_source=external,time_source=external"
+
+is equivalent to
+
+sdr_addrs = "addr=192.168.10.2"
+clock_src = "external"
+time_src  = "external"
+
+Valid choices for clock and time source are "internal", "external", and "gpsdo"
+
+Careful: the USRP remembers the choice of the clock source. If you want to make sure it uses always the same, always specify the clock_source and time_source.
+
+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.
+
+tx_subdev = "A:0"
+rx_subdev = "A:0"
+
+When combining this with the multi USRP feature you can easily create a distributed antenna array with only 1 channel used at each USRP.

radio/USRP/USERSPACE/LIB/usrp_lib.cpp

@@ -1077,18 +1077,28 @@ extern "C" {
       return -1;
     }
 
-    LOG_I(HW,"Found USRP %s\n", device_adds[0].get("type").c_str());
+    std::string type_str, product_str;
+    if (args.find("addr0") != std::string::npos) {
+      type_str = "type0";
+      product_str = "product0";
+    }
+    else {
+      type_str = "type";
+      product_str = "product";
+    }
+    
+    LOG_I(HW,"Found USRP %s\n", device_adds[0].get(type_str).c_str());
     double usrp_master_clock;
 
-    if (device_adds[0].get("type") == "b200") {
+    if (device_adds[0].get(type_str) == "b200") {
       device->type = USRP_B200_DEV;
       usrp_master_clock = 30.72e6;
       args += boost::str(boost::format(",master_clock_rate=%f") % usrp_master_clock);
       args += ",num_send_frames=256,num_recv_frames=256, send_frame_size=7680, recv_frame_size=7680" ;
     }
 
-    if (device_adds[0].get("type") == "n3xx") {
-      const std::string product = device_adds[0].get("product");
+    if (device_adds[0].get(type_str) == "n3xx") {
+      const std::string product = device_adds[0].get(product_str);
       printf("Found USRP %s\n", product.c_str());
       device->type=USRP_N300_DEV;
       if (product == "n320")
@@ -1101,7 +1111,7 @@ extern "C" {
         LOG_W(HW,"Can't set kernel parameters for N3x0\n");
     }
 
-    if (device_adds[0].get("type") == "x300") {
+    if (device_adds[0].get(type_str) == "x300") {
       printf("Found USRP x300\n");
       device->type=USRP_X300_DEV;
       usrp_master_clock = 184.32e6;
@@ -1112,7 +1122,7 @@ extern "C" {
         LOG_W(HW,"Can't set kernel parameters for X3xx\n");
     }
 
-    if (device_adds[0].get("type") == "x4xx") {
+    if (device_adds[0].get(type_str) == "x4xx") {
       printf("Found USRP x400\n");
       device->type = USRP_X400_DEV;
       usrp_master_clock = 245.76e6;