diff --git a/targets/RT/USER/lte-softmodem.h b/targets/RT/USER/lte-softmodem.h
index 2b087e5456..96ab799c3d 100644
--- a/targets/RT/USER/lte-softmodem.h
+++ b/targets/RT/USER/lte-softmodem.h
@@ -98,6 +98,9 @@
 
 #define CONFIG_HLP_DISABLNBIOT   "disable nb-iot, even if defined in config\n"
 
+#define CONFIG_HLP_USRP_ARGS                "set the arguments to identify USRP (same syntax as in UHD)\n"
+#define CONFIG_HLP_USRP_CLK_SRC              "USRP clock source: 'internal' or 'external'\n"
+
 /***************************************************************************************************************************************/
 /* command line options definitions, CMDLINE_XXXX_DESC macros are used to initialize paramdef_t arrays which are then used as argument 
    when calling config_get or config_getlist functions                                                                                 */
@@ -147,7 +150,9 @@
 {"num-ues",     	       		   NULL,		      	  0,				u8ptr:&(NB_UE_INST),	    defuintval:1,   	TYPE_UINT8,	   0},     \
 {"r"  ,                        CONFIG_HLP_PRB,        0,                u8ptr:&(frame_parms[0]->N_RB_DL),   defintval:25,   TYPE_UINT8,    0},     \
 {"dlsch-demod-shift",     	 CONFIG_HLP_DLSHIFT,	0,		  iptr:(int32_t *)&dlsch_demod_shift,	defintval:0,			   TYPE_INT,	  0},			   \
-}
+{"usrp-args",               CONFIG_HLP_USRP_ARGS,   0,                      strptr:(char **)&usrp_args,         defstrval:"type=b200",          TYPE_STRING,    0},                     \
+{"usrp-clksrc",             CONFIG_HLP_USRP_CLK_SRC,0,                      strptr:(char **)&usrp_clksrc,       defstrval:"internal",           TYPE_STRING,    0}                     \
+  }
 
 #define DEFAULT_DLF 2680000000
 
diff --git a/targets/RT/USER/lte-uesoftmodem.c b/targets/RT/USER/lte-uesoftmodem.c
index c52fe130a1..69556b19f2 100644
--- a/targets/RT/USER/lte-uesoftmodem.c
+++ b/targets/RT/USER/lte-uesoftmodem.c
@@ -223,6 +223,9 @@ int numerology = 0;
 char *parallel_config = NULL;
 char *worker_config = NULL;
 
+char* usrp_args=NULL;
+char* usrp_clksrc=NULL;
+
 static THREAD_STRUCT thread_struct;
 void set_parallel_conf(char *parallel_conf)
 {
@@ -739,6 +742,26 @@ void init_openair0(LTE_DL_FRAME_PARMS *frame_parms,int rxgain) {
 	     openair0_cfg[card].tx_freq[i],
 	     openair0_cfg[card].rx_freq[i]);
     }
+
+    if (usrp_args) openair0_cfg[card].sdr_addrs = usrp_args;
+    if (usrp_clksrc) {
+      if (strcmp(usrp_clksrc, "internal") == 0) {
+	openair0_cfg[card].clock_source = internal;
+	LOG_D(PHY, "USRP clock source set as internal\n");
+      } else if (strcmp(usrp_clksrc, "external") == 0) {
+	openair0_cfg[card].clock_source = external;
+	LOG_D(PHY, "USRP clock source set as external\n");
+      } else if (strcmp(usrp_clksrc, "gpsdo") == 0) {
+	openair0_cfg[card].clock_source = gpsdo;
+	LOG_D(PHY, "USRP clock source set as gpsdo\n");
+      } else {
+	openair0_cfg[card].clock_source = internal;
+	LOG_I(PHY, "USRP clock source unknown ('%s'). defaulting to internal\n", usrp_clksrc);	
+      }
+    } else {
+      openair0_cfg[card].clock_source = internal;
+      LOG_I(PHY, "USRP clock source not specified. defaulting to internal\n");	
+    }
   }
 }