odulation technique which can be used over long distances (several kilomete= rs) and up to 20kbits/sec transfer rate.
modulation is often used, but I recently also discoverd PPM-AM which seems = very simple also.
I mean, how well do they work in inclement weather.
PSK is a little better than FSK at avoiding interference because it need a smaller bandwidth to carry the same information. If you don't need the data to get to the other end quickly, you can send at a higher speed and spread error correction coded data out in time.
To see why the spreading of the data out in time helps you have to remember that man made interference and lightning tend to be longish burst like in nature.
Short bursts: Th* q?ick brown ))( jumped over ++e laz&&dov. =3Dhe =3Duic- b||wn fox j+mped o+er the l8zy dqg. T+e qu99k %ro&* fox \\u-000 nv=3D=3D th- -a-y *og.
Long bursts:
****************fox jumped over the lazy dog. The quick brown fox**************** lazy dog. The quick brown fox jumped over the lazy dog.If the error correction information was nearby in time, the second case would be unrecoverable.