Andrew Glasbrenner wrote:
One of the things we are working on is the development of a band plan for the 3.3 GHz to 3.5 GHz allocation. I know that AMSAT is planning something for Eagle that makes use of the 3.3GHz band. Would you please review the chart below and provide some input to allow this band plan to peacefully co-exut with whatever AMSAT is planning?
I would like to know what other uses are proposed for this band. Are they narrowband? Wideband? Digital or analog? Long range or short range? Etc.
This would be helpful in the design of modulation methods as well as bandwidths and frequency selection to minimize or eliminate mutual interference.
The biggest issue is power spectral density. An unmodulated carrier component often causes trouble because it's a spectral line with theoretically infinite power spectral density. On the commercial satellite bands, which historically were shared with terrestrial point-to-point links, the FCC imposes power spectral limits that effectively ban discrete carriers. We don't have those regulations on the ham bands, but we still want to avoid interference.
The usual fix is scrambling or spreading, but this increases complexity so we'd like to know if we have to do it.
Phil