OOK modulation naming

GNU Radio
1

A friend recently showed me an OOK modulation that I had never seen
before, and I’m wondering if anyone knows a name for this scheme.

It is PWM where both the on periods and off periods carry data in their
durations.

In the example we observed, an on or off period with a duration of two
units represents a zero. An on or off period with a duration of one
unit represents a one. Example:

–-–_--__-

This sequence of amplitudes represents the binary data 011101001.

Note that this scheme has a variable data rate. (Two packets carrying
the same number of bits may have different durations.) Overall,
however, the data rate is higher than in a similar looking scheme in
which data are encoded only in the on periods.

Does anyone know what to call this? I am tempted to call it Biphase
PWM.

Thanks,

Mike

2

Why not make the ratio 1:3 and then you could call it Morse PWM. :slight_smile:

3

Hey Mike,

I think that NRZI.

  • Jeff
4

I though NRZI had a constant symbol rate. I would expect 011101001 in
NRZI to look like:

-–___-

Mike

5

Great find, Jeff! I’m also finding it called “Digital Pulse Interval
and Width Modulation” with the same acronym. I think it is clearer with
the “and” in there, and that version of the name dates back at least to
1995.

Mike

6

After way to much searching … under Anisochronous modulation, there is
something called Digital Pulse Interval Width Modulation (DPIWM).

Seems like as good a name as any.

  • Jeff