Hi Peter,
since you're looking at a signal with less than 10MHz bandwidth around
910MHz, you might have hardware available that is able to capture the
whole bandwidth. This should be a good starting point.
Besides, the best approach to solve your challenge depends on more
parameters.
Questions that I'd consider first:
Do you need to process all 6 bands in parallel?
Are all signal sources synchronized? Do they come from the same source?
How large are the guard bands?
How large is the time gap between every sequential hop in a subband?
Do the subbands depend on each other in some way?
Is there a preamble to sync to?
Do you intend to change block parameters at runtime?
It might be interesting to use polyphase filters to divide your ~10MHz
signal into 6 subbands first. Then use a polyphase filter to separate
your channels. Or use the Xlating FIR for your subbands. I'd play around
and observe the effects of each approach.
You might want to use a polyphase filter for all your 6 * 60 channels.
Cheers
Johannes
On 10.07.22 12:18, Peter Lambrechtsen wrote:
Hello,
Excuse my ignorance as I am fairly new to gnuradio but I am trying to
figure out how best to capture a data stream that is in the ISM band
that also has frequency hopping.
Channel spacing of 25kHz
It has two data bit rates of 62.5bps and 500bps
Starting at 910.5Mhz and going up to 919.975 and in there it has 6 sub
bands of 60 channels it hops between sequentially between the
frequencies in the sub band every 0.4s
I'm wondering what the best approach would be to capture the data and
figure out when the timing frame was to determine which was the
initial frame as then it should be able to follow the sequential hopping.
Still trying to work on the blocks to capture all the traffic as I
haven't figured that out yet as I am just working off the specification
and trying to understand the Frequency Xlating FIR Filter to at least
capture one FSK stream to make sure it is sane what I should be
receiving, then move to the frequency hopping.
Thanks, Peter