Sheshanandan KN wrote:
Hi all, Please ignore the previous mail. It is not complete. It was sent accidently.Thanks Eric... I will be more specific about the problem.... here it is... I am trying to combine the spectrum sense and ODFM Tx code together using multi flow graph concept. I idea is to sense the spectrum for occupancy and if free, use that frequency for OFDM transmission. So far I have achieved the connection between spectrum sense flow graph and the OFDM Tx flow graph. I am taking both the spectrum sense parameters and OFDM Tx parameters together at the time of initialization. The code is working fine performing the spectrum sense and ofdm transmission. But the frequency at which the OFDM transmission is happening is not at the frequency sensed to be free. Instead it is happening at the initialized frequency (--tx-freq parameter). I want this parameter to be changed at runtime. I have given following piece of code for the same: class my_top_block(gr.top_block) self.sp_sense = spectrum_sense() self.ofdm_tx = ofdm_transmit() self.connect(ofdm_tx) self.connect(sp_sense) tx = my_top_block() Now, in the main program, I do something like this: if power < threshold: print 'spectrum is free' tx.ofdm_tx._tx_freq = m.center_freq Then I perform ofdm transmission. But the last statement here has no effect in the execution. Please let me know what is the mistake with this kind of change of parameter value. I am looking to have this kind of runtime change in value of parameter.
tx.ofdm_tx._tx_freq is just a variable holding the frequency, but does not set it.
You have to re-tune the usrp (tb.set_freq(new_freq)). Tom _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
