Re: [Discuss-gnuradio] OFDM update

[Robert McGwier]

All resolvable with in-band signaling and RSSI with feedback to agc 
hardware and software.

I know, I know, I am a broken record.

Bob



Tom Rondeau wrote:
> Matt and I have had a bit of a chance to work out some kinks in the OFDM
> world. My latest merge should allow people to operate over the air ok.
> The problem turns out to be false correlations when using the BasicRX
> boards because with the low gain, the noise only toggles the last 1 or 2
> LSBs, which correlate nicely and caused the assertions down the chain.
> The new version avoids that issue as well as provides better default
> parameters to run over the air.
>
> I recommend testing this on an RFX board and not a BasicRX/TX. Also,
> adjust the --tx-amplitude option on the command line for performance.
> It's set low still (200) as opposed to 1. This should be fine for a
> couple of feet. Watch going too high with the amplitude because of
> clipping. I think 4000 was about the max we saw with an RFX400, but
> between 1000 and 2000 should work nicely for in-house tests.
>
> I also set the default packet size to 400, down from 1450 bytes. We have
> not implemented frequency/phase tracking throughout the packet, just on
> the preambles, so rotation throughout the packet can cause high packet
> loss with long packets.
>
> I think this current version provides a usable base for people to play
> with, though it's by no means perfect. However, I've got to bury myself
> in my dissertation, so I won't doing any more work on it for a couple of
> months.
>
> Tom
>
>
>
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