it looks like somebody already made a decoder for a wwvb like
transmission, see here:
Performance Analysis and Receiver Architectures of DCF77
Radio-Controlled Clocks
*
Daniel Engeler
Daniel Engeler
<researcher/75928367_Daniel_Engeler>
Zuhlke Engineering AG, Schlieren, Switzerland.
IEEE transactions on ultrasonics, ferroelectrics, and frequency control
<journal/1525-8955_IEEE_transactions_on_ultrasonics_ferroelectrics_and_frequency_control>
(Impact Factor: 1.5). 05/2012; 59(5):869-84. DOI: 10.1109/TUFFC.2012.2272
Source: PubMed <http://www.ncbi.nlm.nih.gov/pubmed/22622972>
*ABSTRACT* DCF77 is a long-wave radio transmitter located in Germany.
Atomic clocks generate a 77.5-kHz carrier which is amplitude- and
phase-modulated to broadcast the official time. The signal is used by
industrial and consumer radio-controlled clocks. DCF77 faces competition
from the Global Positioning System (GPS) which provides higher accuracy
time. Still, DCF77 and other long-wave time services worldwide remain
popular because they allow indoor reception at lower cost, lower power,
and sufficient accuracy. Indoor long-wave reception is challenged by
signal attenuation and electromagnetic interference from an increasing
number of devices, particularly switched-mode power supplies. This paper
introduces new receiver architectures and compares them with existing
detectors and time decoders. Simulations and analytical calculations
characterize the performance in terms of bit error rate and decoding
probability, depending on input noise and narrow-band interference. The
most promising detector with maximum-likelihood time decoder displays
the time in less than 60 s after power-up and at a noise level of
E(b)/N(0) = 2.7 dB, an improvement of 20 dB over previous receivers. A
field-programmable gate array-based demonstration receiver built for the
purposes of this paper confirms the capabilities of these new
algorithms. The findings of this paper enable future high-performance
DCF77 receivers and further study of indoor long-wave reception.
The DCF77 has very similar modulation scheme as the new wwvb, therefore
the methode used to decode the DCF77 could be used --perhaps with some
modifications -- to decode the phase modulation of the wwvb also
74
KJ6UHN
Alex
On 8/9/2015 7:57 PM, John Allen wrote:
Hi Jim -
You wrote:
At some point, multiproject wafers (like MOSIS) might become a hobby
product. So far, it's in the "several kilobuck" minimum purchase, and,
as well, the tools aren't easy to come by. Or, more properly, good
design tools are expensive, tedious design tools are free.. you CAN
layout an IC for MOSIS with a ruler and and a quadrille pad.. get your
copy of Carver and Mead and have at it)
I assume that you mean Carver Mead and Lynn Conway, Introduction to VLSI System
Design 1978.
I am enjoying this thread!
Regards, John Allen K1AE
-----Original Message-----
From: time-nuts [mailto:[email protected]] On Behalf Of Jim Lux
Sent: Sunday, August 09, 2015 9:12 PM
To: [email protected]
Subject: Re: [time-nuts] wtd: WWVB info
On 8/9/15 4:33 PM, Bob Camp wrote:
Hi
If you never have tried to keep an IC in production, there are some basic things
that may not be very obvious:
<snip>
There's always Rochester Electronics.. "leaders in the trailing edge"
(no kidding, that's their slogan)..
They buy old fabs, masks, etc, and keep producing small runs of older
parts. For a price.
At some point, multiproject wafers (like MOSIS) might become a hobby
product. So far, it's in the "several kilobuck" minimum purchase, and,
as well, the tools aren't easy to come by. Or, more properly, good
design tools are expensive, tedious design tools are free.. you CAN
layout an IC for MOSIS with a ruler and and a quadrille pad.. get your
copy of Carver and Mead and have at it)
For digital stuff, small boards with FPGAs or microcontrollers on them
are probably the sweet spot for small runs.
The same is not true for analog.
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