<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE></TITLE>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.2900.3603" name=GENERATOR></HEAD>
<BODY><!-- Converted from text/plain format --><IMG
style="WIDTH: 383px; HEIGHT: 239px" height=299
src="http://www.mds975.co.uk/Images/amateur_radio/hamscope_ms2.jpg"
width=389><BR>
<H1>MULTIPSK 4.15 released</H1>
<P><FONT face=Verdana>A new version of the popular data modes software
<STRONG>MULTIPSK</STRONG> has been released which features MIL-STD-188-110A also
known as STANAG 4539 or FED-STD-1052</FONT></P>
<P><FONT face=Verdana><STRONG>Patrick F6CTE</STRONG> writes:</FONT></P>
<P><FONT face=Verdana>Hello to all Ham and SWL,</FONT></P>
<P><FONT face=Verdana>The new release of MultiPSK (4.15) is on my Web site
(</FONT><A href="http://f6cte.free.fr/"><FONT
face=Verdana>http://f6cte.free.fr</FONT></A><FONT face=Verdana>).<BR>The main
mirror site is Earl's, N8KBR:<BR></FONT><A
href="http://www.eqth.info/multipsk/index.html" target=_blank><FONT
face=Verdana>http://www.eqth.info/multipsk/index.html</FONT></A><FONT
face=Verdana> (click on "United States Download Site").<BR>Another mirror site
isTerry's: </FONT><A href="http://g90swl.co.uk/multipsk/"
target=_blank><BR><FONT
face=Verdana>http://g90swl.co.uk/multipsk/</FONT></A></P>
<P><FONT face=Verdana>Multispk associated to Clock are freeware programs but
with functions submitted to a licence (by user key).</FONT></P>
<P><FONT face=Verdana>The main modifications of MULTIPSK 4.15 are the
following:</FONT></P>
<P><FONT face=Verdana>1) Decoding of the MIL-STD-188-110A ("110A") + 110A
beacon. This mode (MIL-STD-188-110A/B) is named also FED-STD-1052 or STANAG
4539. It is used mainly by professionals (the text being mostly encrypted) but
also, rarely, by Hams.</FONT></P>
<P><FONT face=Verdana>The 75 bps sub-mode in TX (beacon) is proposed by
Multipsk.</FONT></P>
<P><FONT face=Verdana>Several sub modes (75 to 4800 bps) and two different
interleaving (short and long) are proposed. All modes are fixed frequency,
except a 75 bps (bits per second) sub-mode which is transmitted in "frequency
hopping". It is not decoded in this soft.</FONT></P>
<P><FONT face=Verdana>The receiver should be in USB mode. The bandwidth must
extend from 300 to 3300 Hz (at -30 dB) with a relatively flat frequency response
between 600 and 3000 Hz. The central frequency is, in this case, equal to
1800Hz. It can be selected a 1500 Hz central frequency for Ham
receivers.</FONT></P>
<P><FONT face=Verdana>The soft automatically decodes the speed (75, 150, 600,
1200, 2400 or 4800 bps) and the interleaver (short or long), in different
character formats.</FONT></P>
<P><FONT face=Verdana>The radio-amateur frequency proposed for this mode is
14104 KHz (adjusted on the transceiver).</FONT></P>
<P><FONT face=Verdana>Important: in USA, 110A text transmission is forbidden.
PSE, check if it is allowed in your country.</FONT></P>
<P><FONT face=Verdana>This mode is available for licencied copies, only
(otherwise, the decoding is stopped after 5 minutes). However the 75 bps
sub-mode in format 8N1 (RX/TX) is free.<BR>See specifications further
on.</FONT></P>
<P><FONT face=Verdana>2) RS ID, Call ID (Prop ID)<BR>These identifiers are now
permanently monitored in background, by default (the CPU load being weak). The
management of these identifiers has been improved.</FONT></P>
<P><FONT face=Verdana>For Call ID and "Prop ID" ("Propagation ID"), it is
proposed four frequencies bandwiths for transmission and monitoring.<BR>3590,
7040, 10148, 14075 KHz (to adjust on the transceiver).</FONT></P>
<P><FONT face=Verdana>All the minimum AF band, i.e. from 200 Hz to 2500 Hz can
be used. These frequencies can be favourably scaned ("Transceiver"
button).</FONT></P>
<P><A href="http://f6cte.free.fr/The_RS_ID_easy_with_Multipsk.doc"
target=_blank><FONT
face=Verdana>http://f6cte.free.fr/The_RS_ID_easy_with_Multipsk.doc</FONT></A></P>
<P><A href="http://f6cte.free.fr/The_Call_ID_and_Prop_ID_easy_with_Multipsk.doc"
target=_blank><FONT
face=Verdana>http://f6cte.free.fr/The_Call_ID_and_Prop_ID<BR>_easy_with_Multipsk.doc</FONT></A></P>
<P><FONT face=Verdana>3) Improvements of<BR>- the SdR mode and frequency
management,<BR>- the ARQ FAE mode (in ALE or ALE400),<BR>- the JT65, GMDSS and
SELCAL modes.</FONT></P>
<P><FONT face=Verdana>110A specifications:<BR>Baud rate: 2400.<BR>Modulation:
8PSK (not differential, the exact phase being determined through known data)
with a central frequency of 1800 Hz<BR>Reception mode: USB<BR>Character set:
different synchronous or asynchronous formats are proposed (5 ITA2, 7 bits ASCII
or 8 bits (ASCII+ANSI))<BR>Shape of pulse: raised cosine<BR>Bandwidth: about 3
KHz (300 to 3300 Hz)<BR>Demodulation: coherent<BR>Synchronization: automatic
using the known data<BR>Convolution code: except in 4800 bps, yes. The
constraint lenght is equal to 7 bits,<BR>Interleaving: except in 4800 bps, yes.
Two interleavings are proposed: short or long. However, it is expected the
possibility not to use interleaving.<BR>Pmean/Ppeak: about 0.76 (specific to
Multipsk in TX) Lowest S/N (on Multipsk): + 4 dB in 75 bps mode (first decodings
at +1.5 dB) and + 10 dB in 2400 bps (the signal to noise ratio must be, in
general, very good, to be able to decode this mode, i.e "excellent" at 2400 bps
and "good" at 75 bps).</FONT></P>
<P><FONT face=Verdana>Each frame contains a synchronization preamble phase where
the sub-mode is defined, a data phase where the unknown data is transmitted
(mixed with known data to follow the transmission characteristics) , an "End of
Message" ("EOM") phase and a final flushing phase (to finish de-interleaving and
de-convolution operations).</FONT></P>
<P><FONT face=Verdana>An adaptative equalization is required at this speed (2400
bauds).</FONT></P>
<P><FONT face=Verdana>73</FONT></P>
<P><EM><STRONG><FONT face=Verdana>Patrick
F6CTE</FONT></STRONG></EM></P></BODY></HTML>