Hello Bonnie, I have tried this solution (just to see what it gave), with two PSKFEC31 transmissions transmitting the same text with a shift of 80 Hz. I call this test mode "Quad" because there were two redundancies in time (due to PSKFEC31 itself) and two in frequency, so 2x2 redundancies.
I do some standard tests with Ludwig (DK5KE) and record all this. Afterwards, I compare the results, decoding each signal separatly (two redundancies) and then together (four redundancies). The advantage with the decoding of the QUAD transmission was that I had twice less errors, but the disadvantage was the maximum power transmitted (to stay linear) was also twice less. So I don't do more with this mode. But of course, it is quite interesting. In fact, this principle is applied with large transmission mode as Olivia in 1000 Hz / 32 for example, where the diversity in frequency is very large and explains, partly (because there is also a diversity in time due to the interleaving and the Hadamard time built function) that it is very robust (and it's very below the reality when you compare both!) compared to PSK31 mode, for example. 73 Patrick ----- Original Message ----- From: "expeditionradio" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Saturday, February 18, 2006 5:15 AM Subject: [digitalradio] RMPSK Redundant Multiple PSK31 or PSK63 > Is there any software available that can transmit multiple > carriers of simultaneous redundant PSK31 or PSK63? > > Some PSK31 software programs presently have the capability > to simultaneously receive multiple PSK carriers. But I am > looking for soundcard programs to transmit RMPSK. > > RMPSK (Redundant Multiple PSK) > 2 (or more) carriers of PSK31 separated by 200Hz to 500Hz, > all transmitting "separately" with the same text/information. > The purpose of the "RMPSK" Redundant-Multiple-PSK signal is > to communicate through frequency-selective noise and fading. > > Another big advantage of RMPSK is complete compatibility with > existing amateur standard single carrier PSK31 reception and > transmission. > > In other words, regular PSK31 can talk to RMPSK31, > and RMPSK31 can talk to PSK31. > > Time Synchronisation > The carriers transmit information synchronised with either: > (A) Simultaneous, with "zero" no time delay between carriers. > (B) Fixed synchronized time delay of 0.10sec to 2.50sec. > > It is especially useful for situations where the receiving > station has interference from digital RFI noise sources > (such as RFI, BPL, HomePlug, TVI, computer-I, etc). > > Many of the RFI noise sources we experience now on HF are from > devices such as plasma TV sets, computers, microprocessors, and > other digital semiconductor devices that put out multiple carriers > and frequency-selective noise. Many amateur operators live in > apartments, condos, and flats where noise levels are high and > external antennas are limited. In most of these cases, the > operator does not have control over these noise sources. > > With a frequency-redundant signal being transmitted, the > receiving operator (or the receiving PSK software) can pick > the best carrier signal(s). > > Alternatively, all of the carriers may be combined and/or > voted upon by the software receiver as a type of FEC, > multi-path fading reduction, or frequency-selective fading > reduction. > > In better signal/noise conditions, all of the carriers of the > system may be combined for faster throughput of digital files, > or image information, as an MPSK signal. > > As another alternate example, the content of the carriers > could be multi-media, with one carrier having keyboarding text > and the other carriers having image or data. > > About 5 years ago, one of the commercial products I invented and > developed used a similar technique (Redundant Multiple OFDM) > although I did it with very large (and expensive) DSP engines on > both ends of the comm link. > > In 2005, I proposed this type of RMPSK technique as a solution > for ham operators to communicate signals through BPL - PLC > (Broadband over PowerLine) HF interference. I have not found > any soundcard software that is adaptable to transmitting it yet. > > Bonnie KQ6XA > > > > > > > > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org > > Other areas of interest: > > The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ > DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy > discussion) > > > Yahoo! Groups Links > > > > > > > > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
