Forums

Digital PLL and FM demodulation

Started by ma November 28, 2006
Hello,
    PLL is a good way to do FM demodulation in analogue domain. What about 
its use in digital domain? Why not to use a digital PLL to do FM 
demodulation? what is advantages(if any) and disadvantages of this 
technique?

Regards


ma wrote:
> Hello, > PLL is a good way to do FM demodulation in analogue domain. What about > its use in digital domain? Why not to use a digital PLL to do FM > demodulation? what is advantages(if any) and disadvantages of this > technique? > > Regards > >
A disadvantage of the PLL technique is that it trickier to get it right compared to a discriminator. An advantage is that the threshold (knee in the SNRout vs SNRin curve) can be lower than for a discriminator. Search for the term "threshold extension" to get some ideas. John

ma wrote:

> Hello, > PLL is a good way to do FM demodulation in analogue domain. What about > its use in digital domain?
There are many ways to do FM demodulation in analog or digital domains. Neither way is good or bad. It depends on what is available and what are the performance requirements.
> Why not to use a digital PLL to do FM > demodulation?
Yes, you can do it this way if you like. what is advantages(if any) and disadvantages of this
> technique?
It can provide for somewhat better performance compared to a discriminator. On the other side, the complexity will be significantly higher. Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com
What about when you want to implement in DSP or FPGA? What is advantages and 
disadvantages?

Regards

"Vladimir Vassilevsky" <antispam_bogus@hotmail.com> wrote in message 
news:RGYah.10474$yE6.262@newssvr14.news.prodigy.com...
> > > ma wrote: > >> Hello, >> PLL is a good way to do FM demodulation in analogue domain. What about >> its use in digital domain? > > There are many ways to do FM demodulation in analog or digital domains. > Neither way is good or bad. It depends on what is available and what are > the performance requirements. > >> Why not to use a digital PLL to do FM demodulation? > > Yes, you can do it this way if you like. > > what is advantages(if any) and disadvantages of this >> technique? > > It can provide for somewhat better performance compared to a > discriminator. On the other side, the complexity will be significantly > higher. > > Vladimir Vassilevsky > > DSP and Mixed Signal Design Consultant > > http://www.abvolt.com
1. It depends.
2. Do your homework yourself.
3. Top posting is very rude.

VLV



ma wrote:

> What about when you want to implement in DSP or FPGA? What is advantages and > disadvantages? > > Regards
>>>PLL is a good way to do FM demodulation in analogue domain. What about >>>its use in digital domain? >> >>There are many ways to do FM demodulation in analog or digital domains. >>Neither way is good or bad. It depends on what is available and what are >>the performance requirements. >> >> >>>Why not to use a digital PLL to do FM demodulation? >> >>Yes, you can do it this way if you like. >> >>what is advantages(if any) and disadvantages of this >> >>>technique? >> >>It can provide for somewhat better performance compared to a >>discriminator. On the other side, the complexity will be significantly >>higher. >>