On Sat, Jul 27, 2013 at 12:03 AM, Adeel Anwar <adeela...@gmail.com> wrote: > 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 >> >> >> > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >
Changing this amplitude is *a* way to change the transmit power, but that's not really the purpose of this amplitude. The tx-gain is the better way to change the tx power. At one point you mentioned you were using 35dB gain. Why don't you lower that to 0 and then increase the gain until you have sufficient reception? _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
