Galileo E5a and E5b bands simultaneously receiver with GRC

[David Dima]

Hello,
I am trying to record simultaneously the Galileo IQ E5a and E5b signals with GNU Radio Companion (GRC) as follows:

The UHD: USRP Source main parameters are set up as follows:

- Sampling rate: 20.5Msps

- Channel bandwidth: 50MHz

- Central frequency: 1191.795MHz

- Number of channels: 1 ( Since USRP 2190 model has only 1 local oscillator, it will not be possible to use 2 simultaneously channels for receiving)

The IQ samples are stored in a file for further processing using a configuration file of the GNSS-SDR tool. 

I manage to process and read the E5a signal correctly, but it does not work for E5b. So I think the issue comes from the way I implemented the receiver in GRC.

The question is, if it is necessary to do any intermediate processing of the signal in GRC to accomplish the aforementioned task.

Many thanks in advance,

David