[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] Phase demodulation

From: Daniele Nicolodi
Subject: Re: [Discuss-gnuradio] Phase demodulation
Date: Thu, 17 Jul 2014 12:00:29 +0200
User-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:24.0) Gecko/20100101 Thunderbird/24.6.0

On 03/07/2014 18:41, Bill Dailey wrote:
> Can you explain this a little. I tried that the other night and
> couldn't get it to do anything. I suspect I am setting the bandwidth
> incorrectly or something. I tried that pi/200 - 2pi/100 thing.

Hello Bill,

first, I recommend you to address your replies to the mailing list and
not to me directly, you will have much more chances to receive some
useful answer.

Second, your description of the problem you are encountering is not very
explicative and it makes it very hard to guess what it may go wrong in
your application.

However, the bandwidth setting of the PLL block defines at which offset
frequency from the carrier you are trying to track the gain of the
control loop drops below 1. This affects the PLL capture range: you can
assume that the capture range is equal to the bandwidth, but it depends
on the signal to noise ratio as well.

What you want is to have a bandwidth that is as large as possible but
low enough to do not bleach the modulation you are trying to detect.  I
have absolutely no idea where the recommendation of the pi/200 value
comes from.

The settings for the PLL blocks in GNU radio use the not very intuitive,
but practical for the implementation, unit of rad/sample.  What I do is
to enter formulas that convert value is Hz to rad/sample based on the
sample rate.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]