I am a new user to this group and I am beginning to understanding the bridge between the software and usrp. Let me attempt to answer atleast on of your questions here. The gurus can correct me if I am wrong :-)
> Are the connections from the daughterboards to the > ADC's > hardwired in the USRP the way it is shown in the > figure, > ie, RX-A to ADC-0, RX-B to ADC-1 and the IF output > of the > TV-RX to both ADC-2 and ADC-3 ? I think this is the default wiring: RxA (Jumper 19 )-ADC 0 RxB (Jumper 18 )-ADC 1 TvRx-Real - ADC 2 TvRx-Imaginary-ADC 3 However,you can change these setting using software muxes documented in usrp_standard.h and usrp_basic.h >Why is there a need for 4 DDC implemented in the FPGA? I was thinking about it for some time too. But in a different way. Why not use four DDC's (real A, cmplx A, real B,cmplx B)with just one input and one output? Haven't delved deeply into it but i think the answer lies in the architecture of the AD9862, or the way the FPGA code was designed. Quoting Matt here: "The way the USRP FPGA code is designed, samples sent over the USB bus are always complex. This is not inconsistent with using real samples on the IF, since you downconvert to 0 IF in the FPGA, and so you need both I and Q." > According to usrp_wfm_gui.py the correct MUX seting > for listening to > FM is 0x f0 f0 f0 f2. > To start with, why are we zeroing all Q > channels? If this is done then we should be getting > always a complex number with zero imaginary part... Thats the intention. To receive only the real samples and provide a zero for all the imaginary samples. HTH, Javs __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
