Bonnie, Olivia has similar advantages to other wide data modes that spread the information over a wide enough area and are redundant enough that even if part of the data is damaged, it can print fairly well on the receiving end. PSK31 being a very narrow mode with no FEC, is directly affected by any interference, doppler polar flutter, selective fading and not well suited for the HF ionosphere when conditions are difficult. QPSK31 does not perform better under conditions that cause phase shifting errors so most have stayed with PSK31. PSK63 is less effective than PSK31, but under good conditions can be useful due to double the speed. This is the "official" digital sound card mode for ARES/RACES in my Section.
Until Olivia came along, MFSK16 seemed to me to be the best overall moderate BW mode that could work deeper into the noise than any other amateur data mode. Much deeper than PSK31, as well as operate under conditions that would make PSK31 unuseable. PSK31 cannot tolerate even slight noise bursting, while MFSK16 can tolerate short ones. Modes such as MT-63 can tolerate even longer burst noise, but can not work as deep into the noise as even PSK31. Of course MT63 has the highest speed of all current sound card modes but can not work very deep into the noise compared to the other digital modes. The main problem with Olivia is that in order to get the robust effect you need to use the wider BW modes with slow enough baud rates and that makes it slower than most of the other digital modes. My view is that when you go much below the equivalent of RTTY 45 baud speed, it can be frustratingly slow. Whenever you have something new that can not at least equal older technology, even in one parameter, it can be disappointing. When we tried to use the higher speed Olivia modes (4 tones at 500 Hz BW at 125 baud) even though with a BW larger than MFSK16, on 80 meter HF, the mode was not useable under what I would characterize as typical conditions, while MFSK16 was near perfect copy. I find that in terms of tuning in stations, PSK31 is the easiest, even with very weak signals. Of course Olivia and MFSK16 will still print on the screen even though it is nearly impossible to discern the signal in the waterfall. At that S/N ratio, PSK31 would not even be printing:) 73, Rick, KV9U expeditionradio wrote: > Could someone please point out what advantage Olivia has? > > Or how to operate or configure Olivia to get an advantage over PSK? > > Maybe my equipment isn't set up right to discover the Olivia advantage. > I have been running Olivia for a while, but I have not found any > advantage over BPSK or QPSK. Note: I have not done any testing, or > side-by-side comparisons... just regional and DX QSOs near the noise > floor. > > Olivia requires more bandwidth than standard PSK31 or PSK63. > Even a standard PSK31 seems to get through as good or better than what > I've found with Olivia. PSK63 seems plenty fast enough for most > keyboarding. > > 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 <*> 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/
