Sorry, I meant to write, "For example in SSB, the RF frequency at any
time is equal to the tone frequency of the voice plus the suppressed
carrier frequency (USB)".
I did not mean the tone frequency at any time...etc.
73 - Skip KH6TY
KH6TY wrote:
Max d,
The distinction is simple - If the carriers or tones which create the
bandwidth expansion (or spreading), are accomplished by means of a
spreading signal , i.e., a separate code signal, which is independent
of the data , then it is spread spectrum no matter what you would like
to call it. If the tone frequencies are DEPENDENT on the data, then it
is NOT spread spectrum. For example in SSB, the tone frequency at any
time is equal to the tone frequency of the voice plus the suppressed
carrier frequency (USB). Viewing the signal on a spectrum analyzer
both with and without data input will probably reveal this, which the
FCC will certainly do, now that the question of whether or not ROS is
spread spectrum has been raised.
Jose's original paper on ROS and FHSS defined the three requirements
very clearly.
73 - Skip KH6TY
max d wrote:
Part 97.3 "Definitions" defines: "SS. Spread-spectrum emissions using
bandwidth-expansion modulation emissions having designators with A,
C, D, F, G, H, J or R as the first symbol; X as the second symbol; X
as the third symbol. "
Title 47 Sec. 2.201 is the relevant section formally defining these
symbols. It can be found on the ARRL website.
For a signal to be officially considered Spread Spectrum by the FCC,
it would have to meet a very specific description, or maybe I should
say it should not meet the other specific definitions of emissions.
After my reading of 2.201, I don't think that ROS or Chip64 could be
"officially" defined as Spread Spectrum.
And, the response from the FCC doesn't provide any FCC position or
interpretation of ROS, and further says "The Commission does not
determine if a particular mode "truly" represents spread spectrum as
it is defined in the rules."
Just my thoughts,
Max
NN5L
