25 Mar
2019
25 Mar
'19
9:45 a.m.
Although my understanding of such things far from complete, I have
heard that one of the biggest problems with high data rate radio
is "smearing" of the symbols by multipath, and that if you can
achieve little or no multipath (akin to analog TV "ghosting"), you
can use much less robust modulation schemes to achieve higher symbol
rates.
No doubt Guillaume can correct me on this.
- Brian
On Sun, Mar 24, 2019 at 06:27:04PM -0700, Michael Fox - N6MEF wrote:
Guillaume:
A few questions is I may:
Answer 2 : In order to achieve links with
omnidirectional antennas, you
have to lower the datarate drastically. In order to do so, I would need
to change lots and lots of things in my protocol, which is not designed
for such low datarates. Therefore, I will not make such a development,
sorry.
Why does the choice of antenna pattern affect the data rate?
Also, have you performed any testing to understand data rate vs. SINAD or
SNR? If so, can you show what SINAD or SNR is needed to achieve each of the
modulations (13, 14, 22, 23, 24)?
It appears that the modulation (13, 14, 22, 23, 24) is set statically in the
master and applies to all remotes. Is this correct, or will the master
dynamically change modulation for each client, depending on SNR?
Thanks much,
Michael, N6MEF