Re: LF: Digital modes comparison

[Andy Talbot <andy.g4jnt@googlemail.com>]

It would be very interesting to see those figures normalised to a constant data rate / bandwidth.  For example, PSK31 shown at -10dB is identical to PKK63 at -7dB - well it would be, its the same modulation, just faster.   Ie plot Bits/second/Hz vs. Eb/No, then stick the Shannon limit on the graph and see which lie nearest.

 

The fact that JT65 is at the top is probably because it sits at around 0.27 chars / second, or something like 1.2 B/s.  Although even after normalisation, it would no doubt still score well up.

 

Andy
www.g4jnt.com

On 29 July 2010 21:48, John Bruce McCreath <weazle@hurontel.on.ca> wrote:

Hello LFers,

I found this while web browsing....interesting reading and Mal's favourite mode isn't top dog.

http://kb2hsh.blogspot.com/2010/05/capabilities-of-weak-signal-digital.html

I was looking for sites having info about digital modes on 1,800 kHz. and lower frequencies.

73, J.B., VE3EAR

LowFER Beacon "EAR"
188.830 kHz. QRSS30
EN93dr