Hello All, I have been itching to build my own software defined radio. Unfortunately I have very little experience in embedded design but I would like to know how to get started. Gnuradio has inspired me to build my own and I would like to figure out how to do it. I would like build in such a way that is compatible with the Gnuradio library and also perform similarly to the USRP radios. I have a nice FPGA I can use as a starting point. However, I'm not sure how to pick an AD and DA, build my own downconverter, upconverter boards, etc... Can anyone point me into the right direction?
Build your own Software Defined Radio
Started by ●November 3, 2010
Reply by ●November 3, 20102010-11-03
On Nov 3, 8:50�am, "pacman101" <janpac01@n_o_s_p_a_m.yahoo.com> wrote:> Hello All, > > I have been itching to build my own software defined radio. �Unfortunately > I have very little experience in embedded design but I would like to know > how to get started. �Gnuradio has inspired me to build my own and I would > like to figure out how to do it. �I would like build in such a way that is > compatible with the Gnuradio library and also perform similarly to the USRP > radios. �I have a nice FPGA I can use as a starting point. �However, I'm > not sure how to pick an AD and DA, build my own downconverter, upconverter > boards, etc... > > Can anyone point me into the right direction?This is NOT my area, however, I did do a VERY top-level look at SDR. My suggestion is to look up an article titled _Software-Defined Hardware for Software-Defined Radios_ by John B. Stephensen, published in September of 2002 by the ARRL. Maurice Givens
Reply by ●November 3, 20102010-11-03
On 11/03/2010 06:50 AM, pacman101 wrote:> Hello All, > > I have been itching to build my own software defined radio. Unfortunately > I have very little experience in embedded design but I would like to know > how to get started. Gnuradio has inspired me to build my own and I would > like to figure out how to do it. I would like build in such a way that is > compatible with the Gnuradio library and also perform similarly to the USRP > radios. I have a nice FPGA I can use as a starting point. However, I'm > not sure how to pick an AD and DA, build my own downconverter, upconverter > boards, etc... > > Can anyone point me into the right direction?Do you have a book or reference on receiver design? There's a lot of subtleties to making a good receiver. The ARRL Handbook, even though it is an "amateur" publication, is on the desks of most pro RF engineers in the US. Going beyond that, I'd suggest Hayward's "Introduction to Radio Frequency Design" and "Experimental Methods in RF Design". http://www.powells.com/partner/30696/biblio/9780872591394 http://www.powells.com/partner/30696/biblio/9780872599239 http://www.powells.com/partner/30696/biblio/9780872594920 Neither of the Hayward books are about SDR, although recent Handbooks will certainly go into it. But the Hayward books will give you much of what you need to build down- and up-converters, and the Handbook will outline the SDR stuff, I'm sure. You can relax in the certainty that no matter what ADC and DAC you choose, it'll be wrong -- either the manufacturer will have lied to you in the data sheets, you will have misunderstood, or you'll be using it incorrectly. Even if you get all of that correct, three months (or weeks, or days) after you get your boards working the manufacturer of your converters will announce some new part that'll make what you have obsolete. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" was written for you. See details at http://www.wescottdesign.com/actfes/actfes.html
Reply by ●November 3, 20102010-11-03
pacman101 wrote:> Hello All, > > I have been itching to build my own software defined radio. Unfortunately > I have very little experience in embedded design but I would like to know > how to get started. Gnuradio has inspired me to build my own and I would > like to figure out how to do it. I would like build in such a way that is > compatible with the Gnuradio library and also perform similarly to the USRP > radios. I have a nice FPGA I can use as a starting point. However, I'm > not sure how to pick an AD and DA, build my own downconverter, upconverter > boards, etc... > > Can anyone point me into the right direction?Abandon the idea. SDR is the area which requires professional approach and industrial scale of investment of effort and money. Besides, even if you manege to build something that barely works, what would you do with it? Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com
Reply by ●November 3, 20102010-11-03
> > >pacman101 wrote: > >> Hello All, >> >> I have been itching to build my own software defined radio.Unfortunately>> I have very little experience in embedded design but I would like toknow>> how to get started. Gnuradio has inspired me to build my own and Iwould>> like to figure out how to do it. I would like build in such a way thatis>> compatible with the Gnuradio library and also perform similarly to theUSRP>> radios. I have a nice FPGA I can use as a starting point. However,I'm>> not sure how to pick an AD and DA, build my own downconverter,upconverter>> boards, etc... >> >> Can anyone point me into the right direction? > >Abandon the idea. > >SDR is the area which requires professional approach and industrial >scale of investment of effort and money. > >Besides, even if you manege to build something that barely works, what >would you do with it? > > >Vladimir Vassilevsky >DSP and Mixed Signal Design Consultant >http://www.abvolt.com >Vladimir, It is the skill that I am more interested in, than the actual SDR. I wouldn't make a small simple design. I am thinking about a nice little at home project to use my fpga. There are many people that have made really nice and cheap SDRs. I'm looking into it as a hobby and possibly learn some skills in Embedded design and DSP. I'm not concerned about being outdated, or having the best sdr. Education is more important in certain cases than money.
Reply by ●November 3, 20102010-11-03
>> >> >>pacman101 wrote: >> >>> Hello All, >>> >>> I have been itching to build my own software defined radio. >Unfortunately >>> I have very little experience in embedded design but I would like to >know >>> how to get started. Gnuradio has inspired me to build my own and I >would >>> like to figure out how to do it. I would like build in such a waythat>is >>> compatible with the Gnuradio library and also perform similarly to the >USRP >>> radios. I have a nice FPGA I can use as a starting point. However, >I'm >>> not sure how to pick an AD and DA, build my own downconverter, >upconverter >>> boards, etc... >>> >>> Can anyone point me into the right direction? >> >>Abandon the idea. >> >>SDR is the area which requires professional approach and industrial >>scale of investment of effort and money. >> >>Besides, even if you manege to build something that barely works, what >>would you do with it? >> >> >>Vladimir Vassilevsky >>DSP and Mixed Signal Design Consultant >>http://www.abvolt.com >> > >Vladimir, > >It is the skill that I am more interested in, than the actual SDR. I >wouldn't make a small simple design. I am thinking about a nice littleat>home project to use my fpga. There are many people that have made really >nice and cheap SDRs. I'm looking into it as a hobby and possibly learn >some skills in Embedded design and DSP. I'm not concerned about being >outdated, or having the best sdr. Education is more important in certain >cases than money. >I meant to say I would like a small simple design.
Reply by ●November 3, 20102010-11-03
pacman101 <janpac01@n_o_s_p_a_m.yahoo.com> wrote:> > I have been itching to build my own software defined radio.(snip)> I have a nice FPGA I can use as a starting point.Am I the only one who believes that Software Defined Radio is misnamed when done with an FPGA? FPGAs are programmable hardware, but software. Now, one can implement a programmable processor inside the FPGA, but even so. For low enough IF, one can likely do it using a fast enough processor, but for higher frequencies or direct RF implementations it seems more likely to be done in programmable hardware. -- glen
Reply by ●November 3, 20102010-11-03
On Nov 4, 2:50�am, "pacman101" <janpac01@n_o_s_p_a_m.yahoo.com> wrote:> Hello All, > > I have been itching to build my own software defined radio. �Unfortunately > I have very little experience in embedded design but I would like to know > how to get started. �Gnuradio has inspired me to build my own and I would > like to figure out how to do it. �I would like build in such a way that is > compatible with the Gnuradio library and also perform similarly to the USRP > radios. �I have a nice FPGA I can use as a starting point. �However, I'm > not sure how to pick an AD and DA, build my own downconverter, upconverter > boards, etc... > > Can anyone point me into the right direction?Use a diode instead...
Reply by ●November 3, 20102010-11-03
On Nov 3, 3:27�pm, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:> pacman101 <janpac01@n_o_s_p_a_m.yahoo.com> wrote: > > > I have been itching to build my own software defined radio. � > > (snip) > > > I have a nice FPGA I can use as a starting point. � > > Am I the only one who believes that Software Defined Radio > is misnamed when done with an FPGA? �FPGAs are programmable > hardware, but software. �Now, one can implement a programmable > processor inside the FPGA, but even so. > > For low enough IF, one can likely do it using a fast enough > processor, but for higher frequencies or direct RF implementations > it seems more likely to be done in programmable hardware. > > -- glenA few of the radios I've done have had the "baseband" at or near 100kHz. A trick with a radio design is to put all of your images (from mixing) into the don't care regions. I think the OP should first play with mod/demod methods and get a handle on those first. And then try something like iDEN/Tetris with a quad 16QAM subcarrier modulation all in a 25kHz wide channel. Clay
Reply by ●November 3, 20102010-11-03
"pacman101" <janpac01@n_o_s_p_a_m.yahoo.com> writes:> It is the skill that I am more interested in, than the actual SDR. I > wouldn't make a small simple design. I am thinking about a nice > little at home project to use my fpga. There are many people thatI think it would be fun to explore such a FPGA design through simulation (both Matlab and HDL) if I only could find some raw sampled radio data files somewhere... Petter -- .sig removed by request.
