Just my guess. The rx IQ samples are rotated by a constant phase offset.

On Mon, Jun 22, 2020 at 9:53 PM Marcus D. Leech via USRP-users <
[email protected]> wrote:

> On 06/22/2020 09:14 PM, Ernest Poletaev via USRP-users wrote:
>
> Hello everyone,
>
> I'm new to SDR and trying to implement transmission with AM Modulation
> using uhd library with B205mini board.
>
> Currently I have following procedure:
>
> Set RX and TX parameters for RF frequency, channel 0
> Set sampling frequency to 1M samples per second
> Set RX and TX gain
> Receiving as sc8, sc8
> Transmitting as fc32, sc8
>
> -loop:
>
> Receiving:
>
> As usual with AM demodulation and it is working
>
> Transmitting:
>
> On audio sink get next 4096 samples of 44.1KHz 16 bit PCM raw audio
> Convert each 16 bit sample to complex float with Q=[audio sample
> normalized to -1 - 1] and I = 0
> Resample (simple interpolation) 44100Hz buffer to 1MHz
> Send buffer for transmission
>
> -end loop
>
> As RX and TX have same frequency I can see data on RF Analyzer, but it
> didn't demodulates to an audio signal.
>
> Am I missing something or my assumption is wrong on some steps?
>
> Regards,
> Ernest
>
>
> _______________________________________________
> USRP-users mailing 
> [email protected]http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>
> I'm going to suggest that if you're new to SDR and DSP, you might invest
> the time to install Gnu Radio, which provides a very rich environment
>   for not only constructing DSP flows for most popular SDR radios, but
> also debugging those flows when they don't work out as you expect.
>
>
> _______________________________________________
> USRP-users mailing list
> [email protected]
> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>
_______________________________________________
USRP-users mailing list
[email protected]
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

Reply via email to