[Discuss-gnuradio] Frequency multiplexing at baseband -filters introduce 'DDDDDDDDDDD'

[Damindra Bandara]

Hi,

I am trying to send multiple baseband signals combined using USRP N210. To do that I multiplied the baseband signals by a proper sine wave and added them before transmission. At the receiver I try to filter the signals using bandpass filters, then multiply using the same sinewave and extract the signal. The problem I am facing is that as soon as I add a filter the USRP started to give a sequence of 'DDDDDD' s.  Could somebody please help me to understand what is going on.

If the method I am trying to get the frequency multiplexing at the baseband is wrong could you please give me some instructions to do baseband channel multiplexing. I appreciate if you could give me any help.

Thank you,

Damindra

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Damindra Savithri Bandara,

Ph.D. in Information Technology (Candidate)
George Mason University,
Fairfax,
Virginia