Hello all, After lot of efforts I am able to receive some data one one of the RX channels, but it is too bad. To understand how weak it is, for example, I was actually transmitting a already known data string and then on reception I was comparing it bit-by-bit with the actual packet and in this way I was calculating bit error rate and in case of lost packet I was calculating packet loss rate. It was an already written code for songle RX channel and my BER was around 1.5% and PLR was also around 1.5%. But with two RX channels both these parameters are abouve 10%.
I am unable to understand what should I do to receive better data (of same order as in the case of single RX channel) when I have two RX channels???? Please let me know if I am doing something wrong. I am tried every possibility!!!!!!!!!! Best Regards kaleem ahmad wrote: > > Hallo everyone, > > I dont get any reply so far, may be I can rephrase my question. > > Actually I was expecting that any code which is working fine for a single > antenna, will only need little changes (Mentioned above in 1st post on > this thread) to convert it to multiple antenna. I mean I was expectring > that I would only need to direct streams of two different antennas to > folwgraphs of my already working code. BUT its not working in this way. > > I have read all related posts on this forum and examples related to > multi_usrp in gnuradio_examples but I am unable to understand where I am > doing wrong, I could not find an answer even from "USRP_Documentation", so > please let me know after having a look on code (For code please go above > to first post on this page) where I am doing wrong. > > Do I need to take care of decimation rate when I have two RX channels, I > am using 160 for both (I think only restriction for decim rate is that it > should be equal for both. Is there any thing else?). OR are there some > parameters which need to be handeled differently for 2 RX channels? > > My understanding about deinterleaver is that, it will get the input from > USRP as a single stream as follows: > self.connect(self.u,self.deinter) > and will automatically and correctly divide it into two separate streams, > and we dont need to do anything else, as follows: > self.connect ((self.deinter,0), self.rx_filter, self.fmdemod, self.corr, > self.vec_sink) > self.connect ((self.deinter,1), self.fft_input) > > Is this understanding about deinterleaver correct or do I need to do some > special processing to get these separate streams. > > > Thanks > > Kaleem AHmad > > > kaleem ahmad wrote: >> >> In addition to my above mentioned question, please also comment on what >> should be the value of mux (I am setting 0x3210) and what should be the >> value of fpga_filename, >> >> Please again note that I want to use 2 RFX2400 cards with one USRP1, and >> 2 rx streams will be there each through RX2 antenna of 2 RFX2400 cards >> and there will be one tx stream through any one of these cards. >> >> Best Regards >> >> Kaleem Ahmad >> >> >> >> kaleem ahmad wrote: >>> >>> Hello every one, >>> >>> I am using USRP1 + RFX2400. >>> >>> I want to use 2 RFX2400 cards. Overall I will have 2 RX streams and 1 TX >>> stream from this system. Following are main parts of my RX_Path >>> (complete code for RX-Path is also attached, if you want please have a >>> look on that, TX-path is not here). I am unable to receive anything from >>> any of the channels although the same RX-path was working when I was >>> using a sinle antenna. Only following lines were mainly changed. Please >>> have a look and let me know if my configuration for 2 RX (on separate >>> RFX cards, but one USRP1 main board) and one TX channel. >>> >>> >>> u = usrp.source_c(0, decim_rate=self.usrp_decim, nchan=2 >>> self.subdev = (self.u.db[0][0] , self.u.db[1][0]) >>> self.u.set_mux(gru.hexint(0x3210)) >>> >>> #Set the gain to the midway point >>> self.subdev[0].set_gain(60) >>> self.subdev[1].set_gain(60) >>> >>> #Set the recieve frequency >>> self.r0 = usrp.tune(self.u, 0, self.subdev[0], 2.41e9) >>> self.r1 = usrp.tune(self.u, 1, self.subdev[1], 2.41e9) >>> >>> self.subdev[0].select_rx_antenna( 'RX2') >>> self.subdev[1].select_rx_antenna( 'RX2') >>> >>> self.deinter = gr.deinterleave(gr.sizeof_gr_complex) >>> >>> #enable Auto Transmit/Receive switching >>> self.set_auto_tr(True) >>> >>> self.connect(self.u,self.deinter) >>> self.connect ((self.deinter,0), self.rx_filter, self.fmdemod, self.corr, >>> self.vec_sink) # One RX antenna for regular data reception >>> self.connect ((self.deinter,1), self.fft_input) #Other RX antenna for >>> fft window, this fft will be further processed >>> >>> >>> http://www.nabble.com/file/p24305532/receive_path.py receive_path.py >>> >>> Best Regards >>> >> >> > > -- View this message in context: http://www.nabble.com/2-RX-and-1-TX-channel-tp24305532p24352988.html Sent from the GnuRadio mailing list archive at Nabble.com. _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
