Thanks. I got some off-help list (thanks, Noah!) and think I have it
sussed. There is a trick, though: if you have an even number of
channels, one of them will wrap from the right side of the graft to the
left, and be useless.
So as a practical matter, you might as well design for an odd number,
and then the channel map to get frequency-order has 0 at the center,
counting up on the right side from 1 to int(n/2), counting down on the
left side from n-1 to int(n/2)+1. So for n = 7 (seven channels):
[ 4,5,6,0,1,2,3 ]
I hope I stated that correctly, if not someone please correct me.
(My earlier example was based on the mistaken assumption that you had to
"waste" a channel for an odd number, so I had 8 channels, and tossed one
to get 7. Backwards.)
John
----
On 06/02/2017 04:32 PM, West, Nathan wrote:
It works kind of like an fftshift. The center channel is 0, the lowest
channel is nchannels/2 + 1 or so... I think your mapping could have 4 on
the end to get the whole sequence.
On Fri, Jun 2, 2017 at 11:25 AM, John Ackermann N8UR <j...@febo.com
<mailto:j...@febo.com>> wrote:
Is there a basic rule for how to assign channel numbers to the PFB
channelizer output? I seem to be too dense to figure it out from
the docs. I just want to pull the channels out in order of their RF
frequency, low to high.
I currently have a 7 channel channelizer which seems to work
properly after I farted around to get this map: [5,6,7,0,1,2,3]
using a "Channels" value of 8 (note that channel 4 is thrown away).
Now I want to extend the number of channels, and the number may be
even or odd. From Tom Rondeu's tutorial, I get the sense that the
mapping changes based on even or odd channel count.
Is there a basic rule to develop the map for the case of RFch0 =
ch0, RFch1 = ch1, etc.?
Thanks,
John
_______________________________________________
Discuss-gnuradio mailing list
Discuss-gnuradio@gnu.org <mailto:Discuss-gnuradio@gnu.org>
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
<https://lists.gnu.org/mailman/listinfo/discuss-gnuradio>
_______________________________________________
Discuss-gnuradio mailing list
Discuss-gnuradio@gnu.org
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
