[time-nuts] Homemade GPS Receiver

[paul swed]

It is because of the processing gain and I believe these to be normal
figures.
Not an expert here but when the system de-spreads the signal the
information pops up above the noise since the noise is random and the
spread carrier only appears random.
Regards
Paul
WB8TSL

On Fri, Sep 26, 2014 at 7:22 AM, Andrea Baldoni <erm1eaae7 at ermione.com>
wrote:

> On Fri, Sep 26, 2014 at 10:07:56AM +0100, Dr. David Kirkby (Kirkby
> Microwave Ltd) wrote:
>
> > I don't understand the units of signal strength
> >
> > "The L1 carrier is spread over a 2 MHz bandwidth and its strength at the
> > Earth's surface is -130 dBm. Thermal noise power in the same bandwidth is
> > -111 dBm"
> >
> > Then goes on to talk about the signal being 20 dB below the noise.
>
> Hello David.
>
> It could be because there is a "process gain" associated in demodulating a
> spread spectrum signal.
>
> Best regards,
> Andrea Baldoni
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