Generating IQ data for different modulation schemes.

Hi,

My RF hardware accepts IQ data in digital form, and generates the RF
signal on the trasmit chain. Similarly on the recieve chain it downconverts
the signal and generates a digital IQ data. I need to generate the baseband
IQ data in the software in the transmit chain and similarly recover the
message data from this baseband IQ data.

Could some body throw light on how to do this, and if there is already
some open source code available to do this. I like to use, FSK, PSK or GMSK
or any variations of these modulation schemes.

Giri

On Apr 27, 7:27&#4294967295;am, "gpatnaik" <gpatn...@hotmail.com> wrote:
> Hi,
>
> My RF hardware accepts IQ data in digital form, and generates the RF
> signal on the trasmit chain. Similarly on the recieve chain it downconverts
> the signal and generates a digital IQ data. I need to generate the baseband
> IQ data in the software in the transmit chain and similarly recover the
> message data from this baseband IQ data.
>
> Could some body throw light on how to do this, and if there is already
> some open source code available to do this. I like to use, FSK, PSK or GMSK
> or any variations of these modulation schemes.
>
> Giri

It's really pretty straightforward. You first generate the baseband
waveform that each modulation scheme corresponds to, interpolate to
whatever sample rate your transmitter needs, and you're done. I don't
know of any cookbook solution, but none of these would be very hard to
generate. It may be even easier to use Matlab or something similar to
generate the data and write it to a file for use in your program.

Jason

On Apr 27, 12:27&#4294967295;pm, "gpatnaik" <gpatn...@hotmail.com> wrote:
> Hi,
>
> My RF hardware accepts IQ data in digital form, and generates the RF
> signal on the trasmit chain. Similarly on the recieve chain it downconverts
> the signal and generates a digital IQ data. I need to generate the baseband
> IQ data in the software in the transmit chain and similarly recover the
> message data from this baseband IQ data.
>
> Could some body throw light on how to do this, and if there is already
> some open source code available to do this. I like to use, FSK, PSK or GMSK
> or any variations of these modulation schemes.
>
> Giri

The Tx/Rx frequency is relevant for this IQ generation. Is there
anyway for the software to know this? Or is it super hetrodyne with
fixed IF?

cheers jacko