TKS for the information Rick,
I noted the two S/N figures:
> (with compression on plain text) could do close to 1000 wpm with about
> a+8 to 10 dB S/N. After all even P3 drops to a net throughput of less
It is not a very good performance. For 1000 wpm a more reasonable minimum
S/N might be around
Hi Patrick,
While you might get a lot of different opinions on what is needed for
public service/emergency communications, absolute accuracy is what many
of us consider to be mandatory. And because you are often going to be
operating under less than ideal conditions and locations, having a
rob
Also, in the case of PSK / QAM, the simplest constellations may stand
much more abuse. If you also have different levels (8QAM and more
complex) clipping/limiting affects the Hamming distance and may confuse
symbols.
Once again, KISS may be the best way... 8-)
73,
Jose, CO2JA
---
Patrick
Hello Rick,
RR for all.
> developing a similar sound card protocol for emergency use. It does not
I've never been implicated in emergency use and I don't know what are the
needs.
For example, what is the net absolute throughput required in bits/sec?
Examples:
* Pactor 2 in the most robust sc
Hello Votjech,
> I wonder whether they reference their two tone crest factor to a
> single PSK carrier?
I think that it is the global crest factor as they gives an example: if the
crest factor is 3 dB a 100 W SSB generates 50 watts, so that's true...
> How about to shift one carrier in time by a
Considering the success that Pactor 2 has had, with what is one of the
more bandwidth conserving modes available with very good throughput and
yet only a 500 Hz bandwidth, this may be a "target" to meet by
developing a similar sound card protocol for emergency use. It does not
need to be the e
Hi Patrick.
> The first mode of Pactor 3, with 2 carriers (in BPSK) specifies a
crest factor of 1.9 dB (ratio of 1.55).
> Pactor 2 specifies a crest factor of 1.45 (in ratio)...1.6 dB
>
> Meanwhile, Pactor 2 applies a root raised cosine window which
gives for a one carrier only, a crest factor
