[aprssig] Diversity Reception of APRS over PSK-63?
bruninga at usna.edu
Sat Feb 20 18:46:33 CST 2010
> Subject: ... APRS over PSK-63
> Wow, greatest thing for HF APRS yet !
> I like... 2100 hz version [with] the
> receiver set to the same frequency as
> AX25 APRS, allowing simultaneous
> RX AX25 APRS... and PSK APRS...
Thank heavens that Chris had the forethought to make sure that PSK63 cannot "digipeat". The thing that ruins HF APRS is the clueless operators that try to digipeat on HF!
For that matter, I would hope that PSK63 would replace HF AX.25 APRS entirely so that we dont hae this terrible waste of bandwidth by clueless operators trying to digipeat.
The REAL PREFORMANCE MULTIPLER of APRS on HF is the presence of IGates (AX25 or PSK) that turn the planet into one huge multi-reception DIVERSITY receiver. All it takes is ONE gateway to hear an APRS burst, and that makes it successful. Even if not directly from point A to B, the station B might hear it with good probability from either station C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, or Z who may have gotten it error free.
If we could figure out a way to commbine bits and pieces from all these gateway diversity receivers, then the probablity of error free detection would go way-way-up even higher...
Might need a special APRS-IS dedicated channel to put these pieces togehter in real time. Once a data burst is assembled error free, then it can be injected into the APRS-IS...
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