disney_snoopy <disney_snoopy@hotmail.com> writes:> On Nov 21, 12:17 am, Randy Yates <ya...@ieee.org> wrote: >> disney_snoopy <disney_sno...@hotmail.com> writes: >> > On Nov 20, 11:26 am, glen herrmannsfeldt <g...@ugcs.caltech.edu> >> > wrote: >> >> disney_snoopy <disney_sno...@hotmail.com> wrote: >> >> > I would appreciate if anyone here could help me. >> >> > I was thinking to create a FM stereo with the RDS and L+R and L-R >> >> > channel in Matlab. >> >> > But i doesnt know how to do on that... >> >> > Can anyone here help me plz? >> >> >> What sample rate are you planning to use? If it is a multiple >> >> of 38kHz it would be somewhat easier than other frequencies. >> >> >> -- glen >> >> > Hi Glen, >> >> > For example my audio is 1kHz, my sample rate is 200kHz. And i plan to >> > create out my FM stereo till the 57kHz signal of my RDS. >> > Any help on that in my Matlab on how to write the code or by apply >> > fdatool? >> >> Your continued allusion to fdatool leads me to believe you don't >> have a clue. It's like asking, "How do I apply a 9/16" wrench to >> rebuild my engine?"! >> -- >> Randy Yates % "I met someone who looks alot like you, >> Digital Signal Labs % she does the things you do, >> mailto://ya...@ieee.org % but she is an IBM."http://www.digitalsignallabs.com% 'Yours Truly, 2095', *Time*, ELO - Hide quoted text - >> >> - Show quoted text - > > Please could anyone here help me on the Matlab? > > I know how to plot for the pilot frequency. > But i doesnt know how to plot the L+R and L-R region on Matlab. > > Please help me on how to plot those region.Do you know how the spectrum is structured for a commerical FM signal? What is your input signal? -- Randy Yates % "So now it's getting late, Digital Signal Labs % and those who hesitate mailto://yates@ieee.org % got no one..." http://www.digitalsignallabs.com % 'Waterfall', *Face The Music*, ELO
Create FM stereo from Matlab.
Started by ●November 18, 2009
Reply by ●November 29, 20092009-11-29
Reply by ●November 29, 20092009-11-29
On Nov 21, 12:17�am, Randy Yates <ya...@ieee.org> wrote:> disney_snoopy <disney_sno...@hotmail.com> writes: > > On Nov 20, 11:26�am, glen herrmannsfeldt <g...@ugcs.caltech.edu> > > wrote: > >> disney_snoopy <disney_sno...@hotmail.com> wrote: > >> > I would appreciate if anyone here could help me. > >> > I was thinking to create a FM stereo with the RDS and L+R and L-R > >> > channel in Matlab. > >> > But i doesnt know how to do on that... > >> > Can anyone here help me plz? > > >> What sample rate are you planning to use? �If it is a multiple > >> of 38kHz it would be somewhat easier than other frequencies. > > >> -- glen > > > Hi Glen, > > > For example my audio is 1kHz, my sample rate is 200kHz. And i plan to > > create out my FM stereo till the 57kHz signal of my RDS. > > Any help on that in my Matlab on how to write the code or by apply > > fdatool? > > Your continued allusion to fdatool leads me to believe you don't > have a clue. It's like asking, "How do I apply a 9/16" wrench to > rebuild my engine?"! > -- > Randy Yates � � � � � � � � � � �% "I met someone who looks alot like you, > Digital Signal Labs � � � � � � �% � � � � � � she does the things you do, > mailto://ya...@ieee.org � � � � �% � � � � � � � � � � but she is an IBM."http://www.digitalsignallabs.com% � � � �'Yours Truly, 2095', *Time*, ELO �- Hide quoted text - > > - Show quoted text -my input audio signal is 1kHz and my sampling freq is 200kHz. Please help! Thank You
Reply by ●November 29, 20092009-11-29
disney_snoopy <disney_snoopy@hotmail.com> wrote:> my input audio signal is 1kHz and my sampling freq is 200kHz. > Please help!Generate sum and difference, generate pilot signal, generate AMSC subcarrier with the appropriate phase, add all three together. A little more complicated since 200 isn't a multiple of 38. -- glen
Reply by ●November 30, 20092009-11-30
glen herrmannsfeldt <gah@ugcs.caltech.edu> writes:> disney_snoopy <disney_snoopy@hotmail.com> wrote: > >> my input audio signal is 1kHz and my sampling freq is 200kHz. >> Please help! > > Generate sum and difference, generate pilot signal, generate AMSC > subcarrier with the appropriate phase, add all three together. > > A little more complicated since 200 isn't a multiple of 38.glen, even his specification is incomplete. The input audio should be STEREO, i.e., left and right. -- Randy Yates % "Maybe one day I'll feel her cold embrace, Digital Signal Labs % and kiss her interface, mailto://yates@ieee.org % til then, I'll leave her alone." http://www.digitalsignallabs.com % 'Yours Truly, 2095', *Time*, ELO
Reply by ●November 30, 20092009-11-30
disney_snoopy <disney_snoopy@hotmail.com> writes:> On Nov 21, 12:17 am, Randy Yates <ya...@ieee.org> wrote: >> disney_snoopy <disney_sno...@hotmail.com> writes: >> > On Nov 20, 11:26 am, glen herrmannsfeldt <g...@ugcs.caltech.edu> >> > wrote: >> >> disney_snoopy <disney_sno...@hotmail.com> wrote: >> >> > I would appreciate if anyone here could help me. >> >> > I was thinking to create a FM stereo with the RDS and L+R and L-R >> >> > channel in Matlab. >> >> > But i doesnt know how to do on that... >> >> > Can anyone here help me plz? >> >> >> What sample rate are you planning to use? If it is a multiple >> >> of 38kHz it would be somewhat easier than other frequencies. >> >> >> -- glen >> >> > Hi Glen, >> >> > For example my audio is 1kHz, my sample rate is 200kHz. And i plan to >> > create out my FM stereo till the 57kHz signal of my RDS. >> > Any help on that in my Matlab on how to write the code or by apply >> > fdatool? >> >> Your continued allusion to fdatool leads me to believe you don't >> have a clue. It's like asking, "How do I apply a 9/16" wrench to >> rebuild my engine?"! >> -- >> Randy Yates % "I met someone who looks alot like you, >> Digital Signal Labs % she does the things you do, >> mailto://ya...@ieee.org % but she is an IBM."http://www.digitalsignallabs.com% 'Yours Truly, 2095', *Time*, ELO - Hide quoted text - >> >> - Show quoted text - > > my input audio signal is 1kHz and my sampling freq is 200kHz. > Please help!Why don't you back up and tell us what it is you're trying to do. I mean, is this a class project? -- Randy Yates % "Maybe one day I'll feel her cold embrace, Digital Signal Labs % and kiss her interface, mailto://yates@ieee.org % til then, I'll leave her alone." http://www.digitalsignallabs.com % 'Yours Truly, 2095', *Time*, ELO
Reply by ●November 30, 20092009-11-30
Randy Yates <yates@ieee.org> wrote:> glen, even his specification is incomplete. The input audio should > be STEREO, i.e., left and right.I thought about mentioning that, but decided not to. Otherwise, it is much easier to create the stereo signal with a mono source... -- glen
Reply by ●November 30, 20092009-11-30
On Nov 30, 1:42�pm, Randy Yates <ya...@ieee.org> wrote:> glen herrmannsfeldt <g...@ugcs.caltech.edu> writes: > > disney_snoopy <disney_sno...@hotmail.com> wrote: > > >> my input audio signal is 1kHz and my sampling freq is 200kHz. > >> Please help! > > > Generate sum and difference, generate pilot signal, generate AMSC > > subcarrier with the appropriate phase, add all three together. > > > A little more complicated since 200 isn't a multiple of 38. > > glen, even his specification is incomplete. The input audio should > be STEREO, i.e., left and right. > -- > Randy Yates � � � � � � � � � � �% "Maybe one day I'll feel her cold embrace, > Digital Signal Labs � � � � � � �% � � � � � � � � � �and kiss her interface, > mailto://ya...@ieee.org � � � � �% � � � � � �til then, I'll leave her alone."http://www.digitalsignallabs.com% � � � �'Yours Truly, 2095', *Time*, ELO �Hi Glen and Randy, This is my DSP project. what i am doing is use a software to prove the FM stereo is work which i can get the outlook structure to this FM stereo broadcast. After get the FM stereo structured, apply an audio frequency to this FM stereo and calculate out the THD. What i know from here is the L+R region is 50Hz to 15kHz. How to implement it to the Matlab i really no idea. Hence, now im finding for help or comment on which command i should use to implement the L+R region. I tried to use multiband coding for this region but i found that i cant code my pilot frequency. The only thing that i can do in this Matlab now is only the pilot freq. So now do you all get what i mean and what i want? Thankz
Reply by ●November 30, 20092009-11-30
On Nov 30, 2:20�pm, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:> Randy Yates <ya...@ieee.org> wrote: > > glen, even his specification is incomplete. The input audio should > > be STEREO, i.e., left and right. > > I thought about mentioning that, but decided not to. > > Otherwise, it is much easier to create the stereo signal with > a mono source... > > -- glenCoding below is i use to code the pilot freq. x3 = ((0.5*sin(2*pi*19000*t1))+ (randn(size(t1)))); [f3] = pmtm(x3,4,65536,fs); While for the L+R i cant use this to code.
Reply by ●November 30, 20092009-11-30
disney_snoopy <disney_snoopy@hotmail.com> writes:> On Nov 30, 1:42 pm, Randy Yates <ya...@ieee.org> wrote: >> glen herrmannsfeldt <g...@ugcs.caltech.edu> writes: >> > disney_snoopy <disney_sno...@hotmail.com> wrote: >> >> >> my input audio signal is 1kHz and my sampling freq is 200kHz. >> >> Please help! >> >> > Generate sum and difference, generate pilot signal, generate AMSC >> > subcarrier with the appropriate phase, add all three together. >> >> > A little more complicated since 200 isn't a multiple of 38. >> >> glen, even his specification is incomplete. The input audio should >> be STEREO, i.e., left and right. >> -- >> Randy Yates % "Maybe one day I'll feel her cold embrace, >> Digital Signal Labs % and kiss her interface, >> mailto://ya...@ieee.org % til then, I'll leave her alone."http://www.digitalsignallabs.com% 'Yours Truly, 2095', *Time*, ELO > > Hi Glen and Randy, > > This is my DSP project. > what i am doing is use a software to prove the FM stereo is work which > i > can get the outlook structure to this FM stereo broadcast. After get > the > FM stereo structured, apply an audio frequency to this FM stereo and > calculate out the THD. > > What i know from here is the L+R region is 50Hz to 15kHz. How to > implement > it to the Matlab i really no idea. Hence, now im finding for help or > comment on which command i should use to implement the L+R region. > I tried to use multiband coding for this region but i found that i > cant code my pilot frequency. > The only thing that i can do in this Matlab now is only the pilot > freq. > > So now do you all get what i mean and what i want?Not really. I'm not good at inferring meaning from poorly-constructed sentences. However, I'm almost positive that if you read this: http://en.wikipedia.org/wiki/FM_broadcasting#Modulation_characteristics and can really understand it, especially the section entitled "FM stereo," then you will have answered many of your own questions. It seems you've put the cart before the horse and you are trying to implement a system that you really don't understand - that will never work. -- Randy Yates % "And all you had to say Digital Signal Labs % was that you were mailto://yates@ieee.org % gonna stay." http://www.digitalsignallabs.com % Getting To The Point', *Balance of Power*, ELO
Reply by ●November 30, 20092009-11-30
disney_snoopy <disney_snoopy@hotmail.com> writes:> On Nov 30, 2:20 pm, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote: >> Randy Yates <ya...@ieee.org> wrote: >> > glen, even his specification is incomplete. The input audio should >> > be STEREO, i.e., left and right. >> >> I thought about mentioning that, but decided not to. >> >> Otherwise, it is much easier to create the stereo signal with >> a mono source... >> >> -- glen > > Coding below is i use to code the pilot freq. > > x3 = ((0.5*sin(2*pi*19000*t1))+ (randn(size(t1)))); > > [f3] = pmtm(x3,4,65536,fs);[Pardon me, glen, for stepping in here...] You probably don't want to do things this way. What you probably want to do is first create the sum (s(t)), difference (d(t)), and pilot (p(t)) signals, then sum them to get a composite baseband signal: b(t) = s(t) + d(t) + p(t) Then FM-modulate b(t). Then add the (possibly complex) noise as the final step. Rethinking this whole situation, this problem is probably too advanced for you at this stage. You need to try a few simpler experiments in Matlab first and learn some of the terininology, concepts, and techniques, before tackling a full FM stereo modulator. -- Randy Yates % "Maybe one day I'll feel her cold embrace, Digital Signal Labs % and kiss her interface, mailto://yates@ieee.org % til then, I'll leave her alone." http://www.digitalsignallabs.com % 'Yours Truly, 2095', *Time*, ELO
