Modem description from Peter G3PLX (the modem author):
---
The modem is based on a "raised cosine" shaped tone filter response which
has the property of zero ISI and zero adjacent tone interference with no
sidelobes. Half the channel filter is in the tx and the other half in the
rx, so it'
Yes, my note about bpsk/qpsk was nonsense.
> My understanding of theory is that baud equals the spread between
tones in
> an OFDM or 2* baud in basic multi-tone signal.
As someone noted, it is not ODFM.
> That does not fit with a 50 baud and 75 Hz separation.
Compromise on total signal width a
> A 50 baud signal should have either a 50 Hz or a 100 Hz separation by my
> understanding.
fdmdv modem is NOT OFDM. (would be called OFDMDV if it was)
And even with ofdm, 50baud and 50hz will not work in real world. Try to
googe "ofdm" and "guard interval".
What spacing would an ofdm systen
December 06, 2007 9:19 PM
> To: digitalradio@yahoogroups.com
> Subject: Re: [digitalradio] Re: Technical Question: FDMDV / QPSK in PSK31
>
> On Dec 6, 2007 9:39 PM, Vojtech Bubnik <[EMAIL PROTECTED]> wrote:
> >
>
> >
> > It is QPSK, not BPSK.
> >
&g
] On
Behalf Of Andrew O'Brien
Sent: Thursday, December 06, 2007 9:19 PM
To: digitalradio@yahoogroups.com
Subject: Re: [digitalradio] Re: Technical Question: FDMDV / QPSK in PSK31
On Dec 6, 2007 9:39 PM, Vojtech Bubnik <[EMAIL PROTECTED]> wrote:
>
>
> It is QPSK, not BP
S AEC Montgomery County, TX
http://TheHamNetwork.net
-Original Message-
From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] On
Behalf Of Vojtech Bubnik
Sent: Thursday, December 06, 2007 8:39 PM
To: digitalradio@yahoogroups.com
Subject: [digitalradio] Re: Technical Question:
On Dec 6, 2007 9:39 PM, Vojtech Bubnik <[EMAIL PROTECTED]> wrote:
>
>
> It is QPSK, not BPSK.
>
> 73, Vojtech
>
>
>
And while on the subject of QPSK, here is an old article about PSK31
QPSK that I wrote around 2000 for the Logger32 help files, it
includes quotes from Peter Martinez that he
--- In digitalradio@yahoogroups.com, "Rud Merriam" <[EMAIL PROTECTED]> wrote:
>
> The statement about it being "50 baud, RRC filtered..." confuses me.
>
> My understanding of theory is that baud equals the spread between
tones in
> an OFDM or 2* baud in basic multi-tone signal. That does not fit
w
