diff options
| author | Tom Rondeau | 2011-03-26 12:16:37 -0400 |
|---|---|---|
| committer | Tom Rondeau | 2011-03-26 12:16:37 -0400 |
| commit | d24a3fa25cd213b7a0aeab07da232bdce904af80 (patch) | |
| tree | a8eb0c57f1343f965e7cc7d4c06c1a334d41b4d0 /gnuradio-core | |
| parent | 068fbaa83fbc931abb4ea22c5ab738e1cb6fb3bb (diff) | |
| download | gnuradio-d24a3fa25cd213b7a0aeab07da232bdce904af80.tar.gz gnuradio-d24a3fa25cd213b7a0aeab07da232bdce904af80.tar.bz2 gnuradio-d24a3fa25cd213b7a0aeab07da232bdce904af80.zip | |
Adding phase detector in Costas loop for 8PSK.
Diffstat (limited to 'gnuradio-core')
| -rw-r--r-- | gnuradio-core/src/lib/general/gr_costas_loop_cc.cc | 22 | ||||
| -rw-r--r-- | gnuradio-core/src/lib/general/gr_costas_loop_cc.h | 6 |
2 files changed, 26 insertions, 2 deletions
diff --git a/gnuradio-core/src/lib/general/gr_costas_loop_cc.cc b/gnuradio-core/src/lib/general/gr_costas_loop_cc.cc index f3bfd0951..b77b19745 100644 --- a/gnuradio-core/src/lib/general/gr_costas_loop_cc.cc +++ b/gnuradio-core/src/lib/general/gr_costas_loop_cc.cc @@ -1,6 +1,6 @@ /* -*- c++ -*- */ /* - * Copyright 2006,2010 Free Software Foundation, Inc. + * Copyright 2006,2010,2011 Free Software Foundation, Inc. * * This file is part of GNU Radio * @@ -64,12 +64,30 @@ gr_costas_loop_cc::gr_costas_loop_cc (float alpha, float beta, d_phase_detector = &gr_costas_loop_cc::phase_detector_4; break; + case 8: + d_phase_detector = &gr_costas_loop_cc::phase_detector_8; + break; + default: - throw std::invalid_argument("order must be 2 or 4"); + throw std::invalid_argument("order must be 2, 4, or 8"); break; } } +float +gr_costas_loop_cc::phase_detector_8(gr_complex sample) const +{ + float K = sqrt(2.0) - 1; + + if(abs(sample.real()) >= abs(sample.imag())) { + return ((sample.real()>0 ? 1.0 : -1.0) * sample.imag() - + (sample.imag()>0 ? 1.0 : -1.0) * sample.real() * K); + } + else { + return ((sample.real()>0 ? 1.0 : -1.0) * sample.imag() * K - + (sample.imag()>0 ? 1.0 : -1.0) * sample.real()); + } +} float gr_costas_loop_cc::phase_detector_4(gr_complex sample) const diff --git a/gnuradio-core/src/lib/general/gr_costas_loop_cc.h b/gnuradio-core/src/lib/general/gr_costas_loop_cc.h index 3b4aab86c..181880f1c 100644 --- a/gnuradio-core/src/lib/general/gr_costas_loop_cc.h +++ b/gnuradio-core/src/lib/general/gr_costas_loop_cc.h @@ -89,6 +89,12 @@ class gr_costas_loop_cc : public gr_sync_block int order ) throw (std::invalid_argument); + /*! \brief the phase detector circuit for 8th-order PSK loops + * \param sample complex sample + * \return the phase error + */ + float phase_detector_8(gr_complex sample) const; // for 8PSK + /*! \brief the phase detector circuit for fourth-order loops * \param sample complex sample * \return the phase error |