Hi all, Please share your views regarding the implementation of impulse radio digitally. Let me be more specific, Since UWB is impulse radio and therefore transmission has to occur over a wide band of frequencies. However, the frequency spectrum has to be bandpass, rather than baseband. My question is that can we use a pure digital system to transmit impulses? So, we transmit baseband signals over the air interface? Isn't this one of the reasons why digital modulation is required?
Digital Impulse Radio
Started by ●December 7, 2010
Reply by ●December 7, 20102010-12-07
On 12/07/2010 05:40 AM, Want2Learn wrote:> Hi all, > > Please share your views regarding the implementation of impulse radio > digitally. > > > Let me be more specific, Since UWB is impulse radio and therefore > transmission has to occur over a wide band of frequencies. However, the > frequency spectrum has to be bandpass, rather than baseband. > > > My question is that can we use a pure digital system to transmit impulses? > > So, we transmit baseband signals over the air interface? > > Isn't this one of the reasons why digital modulation is required?The complexity of the antenna in a radio system is related to the relative bandwidth of the signal being transmitted -- i.e. the bandwidth divided by the carrier frequency. The size of the antenna is related to the lowest frequency that must be transmitted. So a signal that ranges from 1Hz to 1.000001MHz will have a huge, and hugely complex antenna, while a signal that ranges from 100MHz to 101MHz will have a simple, small antenna. Digital modulation doesn't have much to do with that. -- 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 ●December 7, 20102010-12-07
Tim Wescott wrote:> On 12/07/2010 05:40 AM, Want2Learn wrote: > >> Let me be more specific, Since UWB is impulse radio and therefore >> transmission has to occur over a wide band of frequencies. However, the >> frequency spectrum has to be bandpass, rather than baseband.> The complexity of the antenna in a radio system is related to the > relative bandwidth of the signal being transmitted -- i.e. the bandwidth > divided by the carrier frequency. The size of the antenna is related to > the lowest frequency that must be transmitted. So a signal that ranges > from 1Hz to 1.000001MHz will have a huge, and hugely complex antenna, > while a signal that ranges from 100MHz to 101MHz will have a simple, > small antenna.The dispersion due to transmit/receive antennae is one of the problems of UWB. This is no simple when the relative frequency range is like x2 or higher. PhD dissertations are made about that. Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com
Reply by ●December 7, 20102010-12-07
On Dec 7, 10:07�am, Tim Wescott <t...@seemywebsite.com> wrote:> On 12/07/2010 05:40 AM, Want2Learn wrote: > > > > > > > > > > > Hi all, > > > Please share your views regarding the implementation of impulse radio > > digitally. > > > Let me be more specific, Since UWB is impulse radio and therefore > > transmission has to occur over a wide band of frequencies. However, the > > frequency spectrum has to be bandpass, rather than baseband. > > > My question is that can we use a pure digital system to transmit impulses? > > > So, we transmit baseband signals over the air interface? > > > Isn't this one of the reasons why digital modulation is required? > > The complexity of the antenna in a radio system is related to the > relative bandwidth of the signal being transmitted -- i.e. the bandwidth > divided by the carrier frequency. �The size of the antenna is related to > the lowest frequency that must be transmitted. �So a signal that ranges > from 1Hz to 1.000001MHz will have a huge, and hugely complex antenna, > while a signal that ranges from 100MHz to 101MHz will have a simple, > small antenna. > > Digital modulation doesn't have much to do with that. > > -- > > Tim Wescott > Wescott Design Serviceshttp://www.wescottdesign.com > > Do you need to implement control loops in software? > "Applied Control Theory for Embedded Systems" was written for you. > See details athttp://www.wescottdesign.com/actfes/actfes.htmlOpps; apparently I don't know the difference between Reply and 'Reply to author', sorry Tim. Does it email you personally or something? To the OP: I was simply adding to Tim's post that in many of the low frequency bands you'll be external noise limited and the effective antenna temperature at the receiver can be negligible due to background noise. But this only "helps" you at the receiver (for example, small antennas for consumer broadcast AM receivers in North American markets). Bryan
Reply by ●December 7, 20102010-12-07
On Dec 8, 2:40�am, "Want2Learn" <telecom.sigpro@n_o_s_p_a_m.yahoo.com> wrote:> Hi all, > > Please share your views regarding the implementation of impulse radio > digitally. > > Let me be more specific, Since UWB is impulse radio and therefore > transmission has to occur over a wide band of frequencies. However, the > frequency spectrum has to be bandpass, rather than baseband. > > My question is that can we use a pure digital system to transmit impulses? > > So, we transmit baseband signals over the air interface? > > Isn't this one of the reasons why digital modulation is required?Subspace communication is far better.
Reply by ●December 7, 20102010-12-07
On 12/07/2010 10:40 AM, Bryan wrote:> On Dec 7, 10:07 am, Tim Wescott<t...@seemywebsite.com> wrote: >> On 12/07/2010 05:40 AM, Want2Learn wrote: >> >> >> >> >> >> >> >> >> >>> Hi all, >> >>> Please share your views regarding the implementation of impulse radio >>> digitally. >> >>> Let me be more specific, Since UWB is impulse radio and therefore >>> transmission has to occur over a wide band of frequencies. However, the >>> frequency spectrum has to be bandpass, rather than baseband. >> >>> My question is that can we use a pure digital system to transmit impulses? >> >>> So, we transmit baseband signals over the air interface? >> >>> Isn't this one of the reasons why digital modulation is required? >> >> The complexity of the antenna in a radio system is related to the >> relative bandwidth of the signal being transmitted -- i.e. the bandwidth >> divided by the carrier frequency. The size of the antenna is related to >> the lowest frequency that must be transmitted. So a signal that ranges >> from 1Hz to 1.000001MHz will have a huge, and hugely complex antenna, >> while a signal that ranges from 100MHz to 101MHz will have a simple, >> small antenna. >> >> Digital modulation doesn't have much to do with that. >> >> -- >> >> Tim Wescott >> Wescott Design Serviceshttp://www.wescottdesign.com >> >> Do you need to implement control loops in software? >> "Applied Control Theory for Embedded Systems" was written for you. >> See details athttp://www.wescottdesign.com/actfes/actfes.html > > Opps; apparently I don't know the difference between Reply and 'Reply > to author', sorry Tim. Does it email you personally or something?That would depend on your newsreader. You would have sent mail to my fake address -- putting your real email address into a USENET post is just engraving an invitation to every spam-bot in the world to include you on their lists.> To the OP: I was simply adding to Tim's post that in many of the low > frequency bands you'll be external noise limited and the effective > antenna temperature at the receiver can be negligible due to > background noise. But this only "helps" you at the receiver (for > example, small antennas for consumer broadcast AM receivers in North > American markets). > > Bryan-- 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 ●December 9, 20102010-12-09
On Dec 7, 2:52�pm, Tim Wescott <t...@seemywebsite.com> wrote:> On 12/07/2010 10:40 AM, Bryan wrote:> That would depend on your newsreader.> ... putting your real email address into a USENET post is > just engraving an invitation to every spam-bot in the world to include > you on their lists....> Wescott Design Serviceshttp://www.wescottdesign.com > > Do you need to implement control loops in software? > "Applied Control Theory for Embedded Systems" was written for you. > See details athttp://www.wescottdesign.com/actfes/actfes.htmlBe careful. I once tried to mediate a brouhaha on another newsgroup. A poster had used a "fake" address that turned out to be someone else's real one. Bitter words were exchanged before the mistaken identity was uncovered.
