Re: [Discuss-gnuradio] OFDM receiver on USRP2
On 02/12/2010 03:53 PM, Srinivas wrote: Matt, There was a frequency offset of ~30 KHz at the Rx w.r.t Tx so I compensated for it and it worked!. The settings I am using is as follows: ./benchmark_ofdm_tx.py -f 2.45G --tx-amplitude 0.9 -M 8 -s 200 -m bpsk --fft-length=512 --occupied-tones=80 -i 64 --tx-gain=10 --cp-length=128 ./benchmark_ofdm_rx.py -f 2.45G -m bpsk --fft-length=512 --occupied-tones=80 -d 64 --rx-gain=20 --cp-length=128 I calculate the data-rate for OFDM as follows Data rate R = (ADC sampling rate x Occupied Tones) / (Nfft x Decimation) For the above setting it is 244 KHz. Am I right with the data rate calculation ? That formula will give you the number of occupied tones per second. You need to multiply by the number of bits per tone to get bps. If you are using BPSK, multiply by 1. If using QPSK, you'll need to multiply by 3, 8PSK by 3, etc. Matt ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] OFDM receiver on USRP2
That formula will give you the number of occupied tones per second. You need to multiply by the number of bits per tone to get bps. If you are using BPSK, multiply by 1. If using QPSK, you'll need to multiply by 3, 8PSK by 3, etc. I meant to say: BPSK - multiply by 1 QPSK - mult by 2 (not 3 like I said above) 8PSK - mult by 3 sorry for the confusion. Matt ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] USRP2 WBX selecting the antenna
Well I am pleased to say that the txrx_wbx.bin firmware from Jason's git seems to work on my USRP2 - WBX combination. These SD cards are strange, I have two identical SD cards same manufacturer (Kingston) size etc. One works and one does not on the USRP2. On both cards the USRP2 lights come on as expected but the USRP2 can't be seen on one of them. Oh well. - Charles ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Firmware / FPGA bitstream for USRP2 Rev 4
Hi, Did you put a static IP address in your Ethernet? Tip, put any dummy static IP address, and you will find your USRP2!!! Best Regard, Firas ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Firmware / FPGA bitstream for USRP2 Rev 4
I had tried that. Didn't help! Thanks though. Best Regards, Omid On Sun, Feb 14, 2010 at 11:05 AM, Firas Abbas wrote: > Hi, > > Did you put a static IP address in your Ethernet? > Tip, put any dummy static IP address, and you will find your USRP2!!! > > Best Regard, > > Firas > > ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] lock and unlock with transmit h_path and receive_path
Hi, I have a similar problem in my code. I modified benchmark_tx.py from gnuradio-examples/ofdm and ofdm.py from blks2impl so that I can change the number of active subcarriers on fly. In the packet sending loop of benchmark_tx I periodically do the following: lock the top block (tb.lock()), call a function in ofdm.py which disconnects the blocks within ofdm_mod: self.disconnect((self._pkt_input, 0), (self.preambles, 0)) self.disconnect((self._pkt_input, 1), (self.preambles, 1)) self.disconnect(self.preambles, self.ifft, self.cp_adder, self.scale, self) rebuild them according to the parameters that I pass from benchmark_tx and reconnects them. After that I call tb.unlock(). What happens is that sometimes it works, and sometimes it gets stuck (some sort of deadlock I assume). I tried swapping lock-unlock with stop-wait-start and that results in similar behavior (it actually goes a few iterations further on average). I also tried moving lock-unlock to the actual function in ofdm_mod, but that didn't change anything. Any suggestions? Thanks, Veljko 2010/2/8 Eric Blossom : > On Sun, Jan 24, 2010 at 02:21:12PM +0100, Carlo Donato Lecce wrote: >> >> Hello all, >> >> >> I seem that using transmit_path and receive_path the reconfigure >> of flow graph is bad. >> The following code hung after the call of unlock. >> >> I think that there are a bugs in the transmit_path because >> using a gr.null_source insted of transmit_path the program not hangs. >> >> Thanks, >> >> >> Carlo. > > Carlo, > > It looks like you're missing the calls to connect that would have your > top block know about the nested blocks. > > See below. > > Eric > > >> from gnuradio import gr, gru, modulation_utils >> from gnuradio import eng_notation >> from gnuradio.eng_option import eng_option >> from optparse import OptionParser >> >> import random, time, struct, sys, math >> >> # from current dir >> from transmit_path import transmit_path >> from receive_path import receive_path >> >> >> class h_block(gr.hier_block2): >> def __init__(self): >> gr.hier_block2.__init__(self, "hello", gr.io_signature(0, 0, 0), >> gr.io_signature(0, 0, 0)) >> >> class top_block(gr.top_block): >> def __init__(self, mod_class, demod_class, rx_callback, options): >> gr.top_block.__init__(self) >> >> self.txpath = transmit_path(mod_class, options) >> self.rxpath = receive_path(demod_class, rx_callback, options) > > Try adding: > > self.connect(self.txpath) > self.connect(self.rxpath) > > here. See also tunnel.py > > >> self.source = gr.null_source(gr.sizeof_gr_complex) >> self.sink = gr.null_sink(gr.sizeof_gr_complex) >> >> >> self.connect(self.txpath, self.sink) >> # self.connect(self.source2, self.sink2) >> >> def reconfigure(self): >> self.lock() >> self.disconnect(self.txpath, self.sink) >> self.sink2 = gr.null_sink(gr.sizeof_gr_complex) >> self.connect(self.txpath, self.sink2) >> self.unlock() > > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Firmware / FPGA bitstream for USRP2 Rev 4
On Sat, Feb 13, 2010 at 11:38:27PM -0600, Omid F wrote: > Thanks Matt for the helpful suggestions. I apologize for the long back and > forths! I really appreciate your help. > > I checked the ethernet interface on two of my laptops. On both, I made sure > this is the setting: > > Pause parameters for eth0: > Autonegotiate: on > RX: on > TX: on Actually what you want is Rx: on Tx: off Eric ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
