Decreasing Quantization Error

GNU Radio
1

Hello,

Is there a way to decrease the A/D quantization error for low input
signals?
I’ve been sending -50dBm to about -70 dBm sine waves to my USRP 1 radio
and
the quantization noise is there.

Is there a way for me to reduce it effectively?

Thanks.

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2

On 10/29/2010 01:14 PM, sirjanselot wrote:

What daughterboard?

ADCs have notoriously-high equivalent noise figure, which can be
overcome by sufficient
low-noise gain in front of the ADC. The usual daughtercards handily
meet this requirement,
except for the Basic_Rx and Basic_Tx, which have no gain.

–
Principal Investigator
Shirleys Bay Radio Astronomy Consortium

3

On 10/29/2010 01:14 PM, sirjanselot wrote:

Also, here’s an interesting article on the subject:

http://www.mwrf.com/Articles/Index.cfm?Ad=1&ArticleID=10586

–
Principal Investigator
Shirleys Bay Radio Astronomy Consortium

4

Hello,

Is it possible to obtain further details on the quantization used in the
daughterboards TVRX and DBSRX (USRP 1)?

I am actually trying to evaluate the noise level on given bands using a
matched load. Unfortunately the noise level seems to be close to the
quantization operator’s step. Consequently, the observed noise samples
do not look quite Gaussian anymore :confused:

Is it possible to alleviate this issue by changing the quantization
parameters? Otherwise to model the quantization effect, I would like to
obtain the mapping function of the quantization operator for these two
boards if possible :slight_smile:

Thanks!!