Hello Samuel,
I just wondering best way to get really sensitive comms, so a 5W HT
could go for miles and miles.
The Wenet project shows what can be done with careful engineering of the
modem, e.g. sending HD images at 100 kbit/s @ 50mW over 100km:
http://www.rowetel.com/?p=5344
The key
The analog FM modulator/demodulator is going to be your main limit. Of
course, we don't have off-the-shelf handheld SDRs yet.
On Sat, Dec 2, 2017 at 1:27 PM, Samuel Hunt wrote:
> Hi Adrian,
>
>
>
> This I understand, but then to double the air rate would then lead to a
>
Hi Adrian,
This I understand, but then to double the air rate would then lead to a net
reduction in sensitivity due to the wider bandwidth.
What I trying to establish is if the coding gain from increasing the error
correction would be more than the sensitivity loss for widening the bandwidth.
Hi,
Channel coding will improve performance, depending on the type of code
used. For example, in QRadioLink I use a rate 1/2 convolutional code,
which leads to twice the symbol rate. This gives me an improvement of
3 dB over no code/half symbol rate mode. LDPC and puncturing would
improve it even
Hi Sam,
I’ll take a stab at your baud question.
Seems to me that lower symbol rate equates to more energy per symbol, and
therefore higher probability of receiving said symbol at the distant station.
At the same received power level, a system with a lower symbol rate will be
more successful
I am hoping there will be some people on this list far more experienced
than me to be able to advise on this!
Am playing with VHF voice, etc, and I am thinking what is the best way
to get ultra-reliable (super-sensitive) performance on a VHF modem.
I am thinking for VHF, based on a radio
On 12/02/2017 09:28 AM, Jacob Falzon wrote:
> Hi there Jereon,
>
> thanks, you're right about the function! Thanks!
>
> What do you mean that the functions would work on any other system
> exactly?
>
The compilation of the modes is conditional, for SM1000 (M4 cortex
actually) they are not