Assuming that there is enough processing power available, and the
architecture physically allows the mixing, manually steering either the
peak or the null should be achievable. There is a slight subtlety in
that one is trying to achieve a constant time delay at RF, not a
constant phase change, but, if RF is sufficiently higher than the the
baseband, it will be a good approximation, and the hardware devices
being quoted probably have the same defect.
Automatically getting a direction is only accurately achievable if the
interfering noise is isotropic, at least in the plane containing the
line between the antennas. As such, it will not be able to automatically
get a direction for an interfering signal, unless it can separate that
signal from everything else, and if it can do that, there may be more
direct ways of removing the signal.
The only way I can see of performing the computation is in the frequency
domain. Although everything starts as just a time delay, the down
conversion preserves phase not time, so I think one needs to do a
Fourier transform, rotate each value by a fixed amount (or one
accounting for the offset from the carrier not being negligible) and
then invert the transform. (There may be better algorithms.)
Because of the discrete nature of FFTs, you would probably want to run
several overlapping transforms and average their results.
I suspect the current DSP tries to avoid doing a full Fourier transform,
and even panoramic adapter FFTs don't need to run overlapping transforms.
I think the big question is does the machine have enough processing
power to do this.
--
David Woolley
Owner K2 06123
On 13/01/2019 01:06, David Gilbert wrote:
these things:
1. Actually amplify a desired signal (probably 2 to 3 db) at the
expense of other signals or generalized noise from other directions.
Hams who put up phased verticals don't do it strictly for the transmit
gain.
2. Totally null out an offending signal or noise from a particular
direction. Your brain most certainly can't do this.
3. Give you angle measurements in degrees.
As I said, I consider the add/subtract ability (#1 and #2) to be more
useful than the simple display of the phase difference (#3), but we
could have both.
Check this out .... https://tinyurl.com/ydfvcauz
It's a hardware implementation of pretty much the same as I'm proposing
Elecraft do in software, and the hardware version goes for $750.
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
