Please tell me about recommend GPS antena and High Frequency Amplifier

GNU Radio
1

Hi,all.

I want to receive GPS L1 signal.and want to analyze location data in PC

Now I use$B!!(Bfollowing GPS antena USRPN200 and DBSRX2. however, GPS
signal’s amplitude is very small. Ican’t see gps signal in FFT

This time I want to change GPS antena.
Please tell me about enough to amplitude of GPS antena.

Thanks

Kouki

2

Hi Kouki,

I don’t think you will see the signal in an FFT window. GPS is spread
spectrum and the signal is below the noise floor. But the signal is
still decodable.

3

2011/12/8 Dan CaJacob [email protected]

Hi Kouki,

I don’t think you will see the signal in an FFT window. GPS is spread
spectrum and the signal is below the noise floor. But the signal is
still decodable.

I thought this was the case; but as someone without any DSP experience
this
boggles the mind… Does anyone have any more info on GPS or how you
decode
it even though you cant “see” a signal?

4
5

In a less mathematical and more qualitative explanation, consider that
at any point in time, one bit of your signal is spread out over a wide
frequency spectrum. If you think of adding up all of the measurements
of little frequency bins across the whole spread spectrum, the noise
in each bin, being random, will average to zero and cancel out, while
signal, being consistently the same, will add up in one direction.

@(^.^)@ Ed