BPL-Busting Modes/Techniques The Digital Voice formats presently in use by hams are not designed to be resistant to QRM from BPL (Broadband over Power Lines). The OFDM digital voice methods require a much higher S/N than SSB.
In fact, most of our present digital and analog modes are not resistant to BPL intereference. However, such BPL-resistant or BPL-Busting digital techniques could be designed into new digital communication formats for HF and VHF. Due to the nature of its resistance to QRM, Olivia 2kHz mode may be the most useful method hams presently have for communicating through BPL interference on HF, but to my knowledge, this has not been tested at a BPL site yet. I have previously suggested a form of RMPSK (Redundant Muliple Phase Shift Keyed) digital format that could be easily implemented, that would be backward compatible, and interoperable with conventional PSK31 and PSK63. Here are a few of the messages regarding this: http://groups.yahoo.com/group/digitalradio/message/13675 Undoubtedly, BPL systems operating in the ham bands cause interference to most of the analog and digital modes we presently use for amateur radio communications. Our main modes: SSB, FM, CW, SSTV, RTTY, PSK31, Pactor, and AM are vulnerable to most of the types of BPL signal interference. Unfortunately, common receiver noise-blanking and DNR techniques are inadequate to cancel the ugly BPL pulsating and multi-carrier signals. The Amateur Radio Service could adopt some form of BPL-mitigation technology, and it may indeed be pushed into it as BPL becomes more widespread. The development of new amateur modes, semi-automated and automated frequency agile systems, advanced ARQ, and various sorts of FEC digital techniques are a possible avenue for amateurs to "communicate through" the interference caused by BPL. It may not be possible to entirely eliminate all the harmful interference BPL creates, but we need to start planning for mitigation. We need to research and characterize the various types of BPL signals so that we can design modulation and control techniques to compensate for them. Using radio engineering and specially-designed digital signal processing, we can develop "BPL-Busting Modes". These new modes and systems could carry any combination of voice/image/text/data. Frequency hopping, spread spectrum, wideband OFDM, multi-PSK, ALE, and MFSK are mode/systems that we could implement immediately in new formats... Unfortunately, hams in USA don't have the freedom within the USA FCC rules to advance some of these yet. We look to hams in other countries to pioneer these new techniques. Under USA FCC current Amateur Radio Service rules, we do not have the freedom that other countries have, to take advantage of some of the most useful technologies that could help us to "communicate through" BPL interference. We are still locked in our technology prison. Hopefully, in the near future, we will have more freedom... with bandwidth-based spectrum management. 73 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/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> 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/
