diff options
Diffstat (limited to 'gnuradio-core/src/lib/general')
| -rw-r--r-- | gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc b/gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc index d1a743f14..cdb5bdc0e 100644 --- a/gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc +++ b/gnuradio-core/src/lib/general/gr_mpsk_receiver_cc.cc @@ -90,12 +90,12 @@ gr_mpsk_receiver_cc::gr_mpsk_receiver_cc (unsigned int M, float theta, // Select a phase detector and a decision maker for the modulation order switch(d_M) { case 2: // optimized algorithms for BPSK - d_phase_error_detector = &gr_mpsk_receiver_cc::phase_error_detector_generic; //bpsk; + d_phase_error_detector = &gr_mpsk_receiver_cc::phase_error_detector_bpsk; //bpsk; d_decision = &gr_mpsk_receiver_cc::decision_bpsk; break; case 4: // optimized algorithms for QPSK - d_phase_error_detector = &gr_mpsk_receiver_cc::phase_error_detector_generic; //qpsk; + d_phase_error_detector = &gr_mpsk_receiver_cc::phase_error_detector_qpsk; //qpsk; d_decision = &gr_mpsk_receiver_cc::decision_qpsk; break; @@ -104,8 +104,6 @@ gr_mpsk_receiver_cc::gr_mpsk_receiver_cc (unsigned int M, float theta, d_decision = &gr_mpsk_receiver_cc::decision_generic; break; } - - set_history(3); // ensure 2 extra input sample is available } gr_mpsk_receiver_cc::~gr_mpsk_receiver_cc () @@ -119,24 +117,21 @@ gr_mpsk_receiver_cc::forecast(int noutput_items, gr_vector_int &ninput_items_req unsigned ninputs = ninput_items_required.size(); for (unsigned i=0; i < ninputs; i++) ninput_items_required[i] = (int) ceil((noutput_items * d_omega) + d_interp->ntaps()); - //ninput_items_required[i] = (int)(d_omega); - } // FIXME add these back in an test difference in performance float gr_mpsk_receiver_cc::phase_error_detector_qpsk(gr_complex sample) const { - float phase_error = ((sample.real()>0 ? 1.0 : -1.0) * sample.imag() - - (sample.imag()>0 ? 1.0 : -1.0) * sample.real()); + float phase_error = -((sample.real()>0 ? 1.0 : -1.0) * sample.imag() - + (sample.imag()>0 ? 1.0 : -1.0) * sample.real()); return -phase_error; } -// FIXME add these back in an test difference in performance float gr_mpsk_receiver_cc::phase_error_detector_bpsk(gr_complex sample) const { - return (sample.real()*sample.imag()); + return -(sample.real()*sample.imag()); } float gr_mpsk_receiver_cc::phase_error_detector_generic(gr_complex sample) const @@ -200,7 +195,10 @@ gr_mpsk_receiver_cc::mm_sampler(const gr_complex symbol) d_phase += d_freq; // increment the phase based on the frequency of the rotation // Keep phase clamped and not walk to infinity - d_phase = gr_branchless_clip(d_phase, M_TWOPI); + while(d_phase > M_TWOPI) + d_phase -= M_TWOPI; + while(d_phase < -M_TWOPI) + d_phase += M_TWOPI; nco = gr_expj(d_phase+d_theta); // get the NCO value for derotating the current sample sample = nco*symbol; // get the downconverted symbol @@ -262,7 +260,10 @@ gr_mpsk_receiver_cc::phase_error_tracking(gr_complex sample) d_phase += d_freq + d_alpha*phase_error; // adjust phase based on error // Make sure we stay within +-2pi - d_phase = gr_branchless_clip(d_phase, M_TWOPI); + while(d_phase > M_TWOPI) + d_phase -= M_TWOPI; + while(d_phase < -M_TWOPI) + d_phase += M_TWOPI; // Limit the frequency range d_freq = gr_branchless_clip(d_freq, d_max_freq); |