[time-nuts] WWVB / Xtendwave patents

[Dennis Ferguson]

On 27 Sep, 2012, at 15:40 , Jim Lux wrote:

> On 9/27/12 2:58 PM, Bob Camp wrote:
>> Hi
>> 
>> It would be interesting to hear what the patent lawyers on the list think about the patents. Given a quick read, they appear to cover any use of the specific transmitted format for receiving time information.
>> 
> IANAL, but..

Me neither.

> reading Claim 1..
> a key aspects are the combination of PSK and ASK, with different data. This is somewhat unusual, and may not have been done exactly like that.
> 
> "said phase modulation *is independent* of the information represented by said pulse width modulation/amplitude shift keyed modulation" is a phrase that occurs in ALL of the independent claims.
> 
> (my emphasis added)
> 
> QAM is, of course, simultaneous PSK and ASK, but it's a single data stream that is being encoded.
> 
> Is there prior art for transmitting one kind of data using ASK and something else PSK?
> 
> For instance, is WWV (which is primarily ASK) has a subcarrier, but the subcarrier is also AM.
> 
> Another possible source of prior art might be a PSK encoded digital squelch on a AM or FM modulated signal (if such a system exists).

I wouldn't mind knowing a legal definition of "information" since to
me most of what is carried in the PSK is the same information as is
carried in the ASK, just formatted with different bits: known markers
to find minute alignment, minute-of-the-century time, leap second warning
and daylight savings information.  The ASK alone encodes UT1 while the
PSK has expanded DST information, but most of it is not what I would call
independent information even if the bit encodings are different.  I assume
a lawyer's definition is not the same as mine.

Beyond that, though, it really does seem like they are attempting to
patent all receivers of the new WWVB format which use the phase
modulation, while pruning the claims enough to avoid existing DCF77
and BPC receivers.  The "timing information based on a known sequence
spanning multiple seconds" avoids DCF77's <0.8 second (and BPC's <0.6
second) known sequence, and "independent information" thing seems to
exist to distinguish it from DCF77 which sends the same bits with both
its PSK and ASK (BPC likely does too).

The not-yet-granted patent actually seems more odious, since it seems
to be attempting to claim the idea of using past time measurements to
compute the frequency error of a clock's oscillator so that future
timekeeping can be improved by correcting that.

That's too bad.  One can only hope the patent they got is defensive and
they don't plan on generally enforcing it, and that none of the claims
in the other one survive the obviousness test.

Dennis Ferguson