Re: [Discuss-gnuradio] quadrature_demod losing weak signals

2013-11-30 Thread Alexandru Csete
On Sat, Nov 30, 2013 at 2:50 AM, Kevin Reid kpr...@switchb.org wrote: This seems like a bug, but I want to check first that I'm not having unreasonable expectations. I'm using GNU Radio 3.7.2. If the amplitude of the input to quadrature_demod_cf is less than about 10^(-2.23), then the

Re: [Discuss-gnuradio] quadrature_demod losing weak signals

2013-11-30 Thread Tom Rondeau
On Sat, Nov 30, 2013 at 5:09 AM, Alexandru Csete oz9...@gmail.com wrote: On Sat, Nov 30, 2013 at 2:50 AM, Kevin Reid kpr...@switchb.org wrote: This seems like a bug, but I want to check first that I'm not having unreasonable expectations. I'm using GNU Radio 3.7.2. If the amplitude of the

Re: [Discuss-gnuradio] quadrature_demod losing weak signals

2013-11-30 Thread Kevin Reid
On Nov 30, 2013, at 2:09, Alexandru Csete oz9...@gmail.com wrote: On Sat, Nov 30, 2013 at 2:50 AM, Kevin Reid kpr...@switchb.org wrote: If the amplitude of the input to quadrature_demod_cf is less than about 10^(-2.23), then the output samples are zero instead of the demodulated signal.

Re: [Discuss-gnuradio] quadrature_demod losing weak signals

2013-11-30 Thread Tom Rondeau
On Sat, Nov 30, 2013 at 10:55 AM, Kevin Reid kpr...@switchb.org wrote: On Nov 30, 2013, at 2:09, Alexandru Csete oz9...@gmail.com wrote: On Sat, Nov 30, 2013 at 2:50 AM, Kevin Reid kpr...@switchb.org wrote: If the amplitude of the input to quadrature_demod_cf is less than about 10^(-2.23),

Re: [Discuss-gnuradio] quadrature_demod losing weak signals

2013-11-30 Thread Kevin Reid
On Nov 30, 2013, at 8:22, Tom Rondeau t...@trondeau.com wrote: On Sat, Nov 30, 2013 at 10:55 AM, Kevin Reid kpr...@switchb.org wrote: /* don't divide by zero! */ if((y_abs 1.5E-5) (x_abs 1.5E-5)) return 0.0; Since the preceding multiply_conjugate should square the magnitude,

[Discuss-gnuradio] quadrature_demod losing weak signals

2013-11-29 Thread Kevin Reid
This seems like a bug, but I want to check first that I'm not having unreasonable expectations. I'm using GNU Radio 3.7.2. If the amplitude of the input to quadrature_demod_cf is less than about 10^(-2.23), then the output samples are zero instead of the demodulated signal. Since such an