In ur GR flowgraph, just add a const-multiply block before USRP-Sink and multiply the Tx signal with it. Set its value between 0-1.
-Adeel On Fri, Jul 26, 2013 at 5:29 PM, yeran <yeran0...@hotmail.com> wrote: > Hi Adeel, > > I'm using RFX 2400 for experiment, there are no parameter > tx-dsp-amplitude. So I can't control tx-power linearly, is that what you > mean? > > Thanks! > Ada > > ------------------------------ > Date: Fri, 26 Jul 2013 04:58:18 +0500 > > Subject: Re: [Discuss-gnuradio] how to raise the packet error rate in > benchmark > From: adeela...@gmail.com > To: yeran0...@hotmail.com; discuss-gnuradio@gnu.org > > >>Currently, what I'm doing is keep the tx-amplitude 0.2, and change the > gain from 35 to 65. You mean in this range, the power is not liner to gain > change, right? If so, is there any way to control or influence the power > change? > I was mentioning about the that total Tx-Power. U can control Tx-power by > varing the value of tx-dsp-amplitude from 0-1 in daughter-boards that don't > have variable tx-gain e.g. RFX2400 otherwise its the combination of both > tx-dsp-amplitude and tx-gain. > > > -Adeel > > > On Thu, Jul 25, 2013 at 9:10 PM, yeran <yeran0...@hotmail.com> wrote: > > Hi Adeel, > > Thanks for your prompt reply! > > I don't quite understand your last email. If I want to test the > performance of transmission under different power allocation. What should I > do? Can you please be more specific about this? > > Currently, what I'm doing is keep the tx-amplitude 0.2, and change the > gain from 35 to 65. You mean in this range, the power is not liner to gain > change, right? If so, is there any way to control or influence the power > change? > > Thank you! > > Regards, > Ada > > ------------------------------ > Date: Wed, 24 Jul 2013 06:12:15 +0500 > Subject: Re: [Discuss-gnuradio] how to raise the packet error rate in > benchmark > From: adeela...@gmail.com > To: yeran0...@hotmail.com; discuss-gnuradio@gnu.org > > > Ada, > > >>once the signal has been up converted. Now I'm using 0.2 amplitude and > 35 gain. But I don't understand, how come that the smaller the power is, > the better transmission performance there will be. And also, why does power > should be in the range of 0 to 1.0? How to calculate transmission power > using the -tx-amplitude and tx-gain? > Better performance is not due to smaller power but it is due to the > non-linear effects of RF-amplifiers. As per my observations, Tx-Dsp > amplitude beyond 0.15 to 0.2 causes the USRP daughter-boards > Tx-amplification-stage to go into non-linear region thus error-rate of > PSK/QAM increases. Non-linear modulation e.g. FSK/GMSK are more robust to > Amps non-linear effects. so u can experiment increasing TX-amplitude both > for FSK-variants & PSK/QAM and observe performance. > > -Adeel > > > On Tue, Jul 23, 2013 at 9:25 PM, yeran <yeran0...@hotmail.com> wrote: > > Hi everyone, > > I'm doing a project on joint decode. But my problem is that in the lab > environment, the benchmark transmission is always good, there are hardly > any packet loss, so I can not show the advantage of joint decode. > > I've tried to change the physical distance from transmission to receiver > attenna. Still works really well even put in opposite side of the building. > > I've tried to change the transmission power and transmission rate. > Inspired by some previous study, I learned that transmission power is > controlled by -tx-amplitude and -tx-gain, in which -tx-amplitude sets the > amplitude of the signal going into the DAC. RF gain is applied in the > daughtercard once the signal has been up converted. Now I'm using 0.2 > amplitude and 35 gain. But I don't understand, how come that the smaller > the power is, the better transmission performance there will be. And also, > why does power should be in the range of 0 to 1.0? How to calculate > transmission power using the -tx-amplitude and tx-gain? > > Is there any other way that may cause more error in transmission beside > the ones I mentioned? > > Thanks in advance! Any suggestion will be greatly appreciated! > > Ada > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > >
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