[Discuss-gnuradio] AGC for PAM

I'm working on a BPSK demodulator, which I guess is a kind of PAM. The signal has some inherent ISI so I'm using Viterbi to decode it. It's working well in idealized conditions, but I'm a bit lost on how to get the amplitude right. It seems important that the amplitude is consistent (modulo noise)

Re: [Discuss-gnuradio] AGC and Dynamic Range of ADC

Well that is 80 dB of dynamic range inside the Nyquist zone (at best and let's call it N). I can add a "bit" of increase in dynamic range by downsampling (filter and decimation) and growing the accumulator size by a bit for each decimation by 4. This will increase dynamic range. I don't believe

Re: [Discuss-gnuradio] AGC and Dynamic Range of ADC

On 09/24/2013 10:30 AM, bob wole wrote: On 09/23/2013 11:07 PM, bob wole wrote: Can somebody please guide me on this ? Bob On Fri, Sep 20, 2013 at 4:44 PM, bob wole > wrote: I have USRPN210 with WBX and RFX2400. Is there any AGC chip on N210 motherboard or WBX

Re: [Discuss-gnuradio] AGC and Dynamic Range of ADC

On 09/23/2013 11:07 PM, bob wole wrote: Can somebody please guide me on this ? Bob On Fri, Sep 20, 2013 at 4:44 PM, bob wole wrote: > I have USRPN210 with WBX and RFX2400. Is there any AGC chip on N210 > motherboard or WBX, RFX2400 before ADC to utilize the dynamic range of ADC > ? if yes, wh

Re: [Discuss-gnuradio] AGC and Dynamic Range of ADC

On 09/23/2013 11:07 PM, bob wole wrote: Can somebody please guide me on this ? Bob On Fri, Sep 20, 2013 at 4:44 PM, bob wole > wrote: I have USRPN210 with WBX and RFX2400. Is there any AGC chip on N210 motherboard or WBX, RFX2400 before ADC to utilize the dyn

Re: [Discuss-gnuradio] AGC and Dynamic Range of ADC

Can somebody please guide me on this ? Bob On Fri, Sep 20, 2013 at 4:44 PM, bob wole wrote: > I have USRPN210 with WBX and RFX2400. Is there any AGC chip on N210 > motherboard or WBX, RFX2400 before ADC to utilize the dynamic range of ADC > ? if yes, which one? If not, then won't the varying i

[Discuss-gnuradio] AGC and Dynamic Range of ADC

I have USRPN210 with WBX and RFX2400. Is there any AGC chip on N210 motherboard or WBX, RFX2400 before ADC to utilize the dynamic range of ADC ? if yes, which one? If not, then won't the varying input signal (for example signal from moving object) to ADC affect the performance of ADC ? Bob __

Re: [Discuss-gnuradio] AGC on the RFX900 board

Thanks, Marcus, for your prompt and detailed response. If I understand you correctly: 1. The best case noise figure of the RFX900 daughterboard is about 3-3.8 dB. This occurs when the mixer amplifiers are set to their highest gain setting. 2. These gain settings can be fixed via software (via UHD)

Re: [Discuss-gnuradio] AGC on the RFX900 board

On 07/03/2011 08:05 PM, Sundaram Vanka wrote: > Hi, > > I have a few questions about the (analog) AGC on the AD8347 mixer chip > on the Flex900 daughterboard. > > 1. Given a signal received with some known power, is it possible to > read the programmed AGC gains (and thereby find the mixer's noise

[Discuss-gnuradio] AGC on the RFX900 board

Hi, I have a few questions about the (analog) AGC on the AD8347 mixer chip on the Flex900 daughterboard. 1. Given a signal received with some known power, is it possible to read the programmed AGC gains (and thereby find the mixer's noise figure)? 2. Is it possible to lock these gain settings? If

Re: [Discuss-gnuradio] AGC settings explanation?

On Wed, Jun 17, 2009 at 08:00, Jamin Chan wrote: > I want to use AGC to control RF output level to be at a set value no > matter what the input level.  I see the gr.agc_cc module has the > following settings and defualt values: > rate (1e-4) > ref (1.0) > gain (1.0) > max_gain (0.0) > > can somebo

[Discuss-gnuradio] AGC settings explanation?

I want to use AGC to control RF output level to be at a set value no matter what the input level. I see the gr.agc_cc module has the following settings and defualt values: rate (1e-4) ref (1.0) gain (1.0) max_gain (0.0) can somebody explain what these settings do? I assume reference sets the des

[Discuss-gnuradio] AGC and PGC

Dear all, I would like to compare two signals in two distinct bands of frequencies (energy in particular) with the TVRX module. Is there an AGC in the USRP/TVRX module ? If yes, how can I get its value ? How the programmable gain (set with the command set_gain of the sub device) impacts on the

[Discuss-gnuradio] AGC questions

Sorry if I'm writing to the wrong direction, it's the first time I'm doing this. I was interested in making a AGC (automatic gain control), however, the one that's supplied doesn't help at all. I wanted to change the usrp.set_gain every time the input power is or too hi or too low. For example, if

Re: [Discuss-gnuradio] AGC loop and digital mods

svn co svn://206.216.146.154/svn/repos_sdr_dttsp/trunk dttsp 'Eric Blossom' wrote: On Wed, Sep 27, 2006 at 01:44:34PM -0400, Robert W McGwier wrote: The feedforward AGC system in DttSP is more complex in that it is two track (fast and "user set"). I believe I already mentioned this so I

Re: [Discuss-gnuradio] AGC loop and digital mods

On Wed, Sep 27, 2006 at 01:44:34PM -0400, Robert W McGwier wrote: > The feedforward AGC system in DttSP is more complex in that it is two > track (fast and "user set"). I believe I already mentioned this so I > won't go over it again. But let me reiterate one important feature of > our work.

Re: [Discuss-gnuradio] AGC loop and digital mods

The feedforward AGC system in DttSP is more complex in that it is two track (fast and "user set"). I believe I already mentioned this so I won't go over it again. But let me reiterate one important feature of our work. One of the things that was important to its success as a feedforward ag

Re: [Discuss-gnuradio] AGC loop and digital mods

On Mon, Sep 25, 2006 at 11:35:33PM -0400, Tom Rondeau wrote: > Eric, > > Here's a brief write-up on the tests I ran for the AGC loops. It looks like > the feedforward has a slight advantage over most of the test cases. > > I thought I'd email this to the listserv in case anyone is interested in

[Discuss-gnuradio] AGC loop and digital mods

Eric, Here's a brief write-up on the tests I ran for the AGC loops. It looks like the feedforward has a slight advantage over most of the test cases. I thought I'd email this to the listserv in case anyone is interested in the digital modulations. Basically, we're working on getting stable DBPSK

Re: [Discuss-gnuradio] AGC loop

On Thu, Sep 21, 2006 at 12:20:50PM -0400, Robert W McGwier wrote: > Eric Blossom wrote: > > >On Tue, Sep 19, 2006 at 01:36:55PM -0400, Robert W McGwier wrote: > > > >>Tom: > >> > >>A good agc has at least two time constants. One for attack and one for > >>decay. Your attack is much too slow. >

Re: [Discuss-gnuradio] AGC loop

Bob McGwier wrote: Eric Blossom wrote: On Tue, Sep 19, 2006 at 01:36:55PM -0400, Robert W McGwier wrote: Tom: A good agc has at least two time constants. One for attack and one for decay. Your attack is much too slow. tmp = (reference - sqrt(real(y)^2 + imag(y)^2)); rate = rate1; if

Re: [Discuss-gnuradio] AGC loop

Eric Blossom wrote: On Tue, Sep 19, 2006 at 01:36:55PM -0400, Robert W McGwier wrote: Tom: A good agc has at least two time constants. One for attack and one for decay. Your attack is much too slow. tmp = (reference - sqrt(real(y)^2 + imag(y)^2)); rate = rate1; if tmp > gainrate

Re: [Discuss-gnuradio] AGC loop

On Tue, Sep 19, 2006 at 01:36:55PM -0400, Robert W McGwier wrote: > Tom: > > A good agc has at least two time constants. One for attack and one for > decay. Your attack is much too slow. > > tmp = (reference - sqrt(real(y)^2 + imag(y)^2)); > rate = rate1; > if tmp > gainrate = rate2; >

RE: [Discuss-gnuradio] AGC loop

uradio mailing list' > Subject: Re: [Discuss-gnuradio] AGC loop > > Tom: > > A good agc has at least two time constants. One for attack and one for > decay. Your attack is much too slow. > > tmp = (reference - sqrt(real(y)^2 + imag(y)^2)); > rate = rate1; > i

Re: [Discuss-gnuradio] AGC loop

Tom: A good agc has at least two time constants. One for attack and one for decay. Your attack is much too slow. tmp = (reference - sqrt(real(y)^2 + imag(y)^2)); rate = rate1; if tmp > gainrate = rate2; gain += tmp*rate; rate2 is decay (where gain needs to be increased) and rate1 is

Re: [Discuss-gnuradio] AGC loop

Do you already have some extra "sacrificial bits" that you send out to allow for the AGC to settle? How long is it taking for the AGC to settle? You could try adding some extra sacrificial bits that you ramp up when you transmit to try to allow for steady tracking in the AGC loop instead of havi

[Discuss-gnuradio] AGC loop

Ok, so I've been working on the digital modulations, and everything works great except when I put in the AGC loop. It jumps up in gain when there is no signal applied and then takes too long to converge when the signal comes in. The result is that it almost always misses the first packet before con

Re: [Discuss-gnuradio] AGC

Johnathan Corgan wrote: > Matt Ettus wrote: > >> I don't have the agc code in front of me, but the definition >> of the setpoint in important. Assuming you make the setpoint 1, >> and that the agc is setting the average (of either I or Q) to >> the setpoint, the amplitude will go from 0 to 2,

Re: [Discuss-gnuradio] AGC

Matt Ettus wrote: > I don't have the agc code in front of me, but the definition > of the setpoint in important. Assuming you make the setpoint 1, > and that the agc is setting the average (of either I or Q) to > the setpoint, the amplitude will go from 0 to 2, since this is AM. > You will ne

Re: [Discuss-gnuradio] AGC

> More interestingly, I'm using complex_to_mag to demodulate a 32K sps > baseband channel as AM, then filtering/decimating the resulting audio. > > If I set the AGC reference value (second parameter) to anything above > 0.2 (including the default 1.0), the audio comes out distorted. It > sounds li

Re: [Discuss-gnuradio] AGC

Tom Rondeau wrote: > I've used both the floating point and complex implementations of the AGC > block, and they work fine. For most signals, using (1e-4, 1, 1) will adjust > the gain to output a signal at +1 and -1. The second term will be the final > peak output value you will get. If I'm remembe

RE: [Discuss-gnuradio] AGC

Of Michael Milner > Sent: Thursday, June 01, 2006 2:54 PM > To: discuss-gnuradio@gnu.org > Subject: [Discuss-gnuradio] AGC > > Hi, > > Can I use the gr_agc code as a block in a flow graph? > > I have an arbitrary float signal that I would like to always have the same &g

[Discuss-gnuradio] AGC

Hi, Can I use the gr_agc code as a block in a flow graph? I have an arbitrary float signal that I would like to always have the same voltage peak to peak regardless of the input signal. Is this possible? I'm using gnuradio 2.8 Thanks! Mike ___ Di

Re: [Discuss-gnuradio] AGC using RXPGA on MxFE

On Fri, Jul 22, 2005 at 05:11:35PM -0700, Eric Blossom wrote: > On Sat, Jul 23, 2005 at 04:35:05AM +0500, Ahmad Sheikh wrote: > > > > But using usrp.source_c().set_pga() means that the feedback control > > be on the python level, which would mean that there would be a large > > latency in the gain

Re: [Discuss-gnuradio] AGC using RXPGA on MxFE

On Sat, Jul 23, 2005 at 04:35:05AM +0500, Ahmad Sheikh wrote: > > But using usrp.source_c().set_pga() means that the feedback control > be on the python level, which would mean that there would be a large > latency in the gain control. Isn't there some way to do this on the > hardware? > -Ahmad Th

Re: [Discuss-gnuradio] AGC using RXPGA on MxFE

Hi, Eric Would you please iterate more on the concept of PGA? I don't understand it quite well. Is it just an amplifier after the ADC, so that the 16-bit signed integer is multiplied by the value of pga? Or, let's say the pga is 10, is it true that the p-p value of the adc is not 1V--1V, but 0.1

Re: [Discuss-gnuradio] AGC using RXPGA on MxFE

On Tue, Jul 19, 2005 at 11:13:31AM -0700, Sachi wrote: > Hi, Eric > > Would you please iterate more on the concept of PGA? It's an analog amplifier with a software controllable gain. On the Rx path it has steps of 1.0 dB. On the Tx path, the steps are 0.1 dB. See the AD9862 datasheet for deta

Re: [Discuss-gnuradio] AGC using RXPGA on MxFE

On Tue, Jul 19, 2005 at 06:08:27AM +0500, Ahmad Sheikh wrote: > The USRP user guide states that there is 20 db of gain on the > USRP. Assuming that this is on the Receive path Programmable Gain > Amplifier on the MxFE, can this be used as an AGC? Yes. > I want to control the strength of the sign

[Discuss-gnuradio] AGC using RXPGA on MxFE

The USRP user guide states that there is 20 db of gain on the USRP. Assuming that this is on the Receive path Programmable Gain Amplifier on the MxFE, can this be used as an AGC? I want to control the strength of the signal received. The way to do this, I think, would be to dynamically alter the