On 07/20/2011 12:24 PM, Yan Nie wrote: > Dear all, > > I am using USRP N200 +UHD with the LFRX daughter board to detect a > 100kHz coded sinusoid wave then down convert the signal to baseband > to see the coding method. The flow graph I am using is: > > u2=uhd.single_usrp_source(device_addr="addr=192.168.10.2",io_type=uhd.io_type_t.COMPLEX_INT16,num_channels=1) > decim_coeffs = gr.firdes.low_pass(1.0, 60e3, #sampling frequency > 30e3, #cutoff frequency .1e3, gr.firdes.WIN_BLACKMAN) > decim_filter = gr.fir_filter_fcc(1,decim_coeffs) > dst=gr.file_sink(gr.sizeof_gr_complex, filename) connect(u2, > decim_filter,dst) > > I am curious about how to configure the io_type_t for the receiver? > COMPLEX_INT16 represents complex signed integer, 16-bit integer. I > found only this io type could match the type provided for the input > of fir_filter. Do I misunderstand something for this io type > selection? >
well, sizeof(complex<short>) == sizeof(float), which means gnuradio will let you connect those blocks, but that definitively wont work. For the UHD source, use COMPLEX_FLOAT32. For the FIR filter, use complex input. gnuradio-companion might help you a lot: http://en.wikipedia.org/wiki/GNU_Radio_Companion -josh _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
