diff options
| author | Tom Rondeau <trondeau@vt.edu> | 2012-08-12 22:36:39 -0400 |
|---|---|---|
| committer | Tom Rondeau <trondeau@vt.edu> | 2012-08-12 22:36:39 -0400 |
| commit | 719ebae8fb75635f1291e21b74af69cbdefe4837 (patch) | |
| tree | e166f92baf4a1ff8940cadfea24e035aac41bd16 /gr-digital/include/digital/costas_loop_cc.h | |
| parent | 78d149cd3d230ca9310401496e5770401aeb478c (diff) | |
digital: converted correlator blocks to 3.7; everything to make qa_correlate_access_code work.
Diffstat (limited to 'gr-digital/include/digital/costas_loop_cc.h')
| -rw-r--r-- | gr-digital/include/digital/costas_loop_cc.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/gr-digital/include/digital/costas_loop_cc.h b/gr-digital/include/digital/costas_loop_cc.h new file mode 100644 index 0000000000..bad6de9363 --- /dev/null +++ b/gr-digital/include/digital/costas_loop_cc.h @@ -0,0 +1,75 @@ +/* -*- c++ -*- */ +/* + * Copyright 2006,2011,2012 Free Software Foundation, Inc. + * + * This file is part of GNU Radio + * + * GNU Radio is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3, or (at your option) + * any later version. + * + * GNU Radio is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GNU Radio; see the file COPYING. If not, write to + * the Free Software Foundation, Inc., 51 Franklin Street, + * Boston, MA 02110-1301, USA. + */ + +#ifndef INCLUDED_DIGITAL_COSTAS_LOOP_CC_H +#define INCLUDED_DIGITAL_COSTAS_LOOP_CC_H + +#include <digital/api.h> +#include <gr_sync_block.h> + +namespace gr { + namespace digital { + + /*! + * \brief A Costas loop carrier recovery module. + * \ingroup sync_blk + * \ingroup digital + * + * The Costas loop locks to the center frequency of a signal and + * downconverts it to baseband. The second (order=2) order loop + * is used for BPSK where the real part of the output signal is + * the baseband BPSK signal and the imaginary part is the error + * signal. When order=4, it can be used for quadrature + * modulations where both I and Q (real and imaginary) are + * outputted. + * + * More details can be found online: + * + * J. Feigin, "Practical Costas loop design: Designing a simple + * and inexpensive BPSK Costas loop carrier recovery circuit," RF + * signal processing, pp. 20-36, 2002. + * + * http://rfdesign.com/images/archive/0102Feigin20.pdf + * + * The Costas loop can have two output streams: + * stream 1 is the baseband I and Q; + * stream 2 is the normalized frequency of the loop + */ + class DIGITAL_API costas_loop_cc : virtual public gr_sync_block + { + public: + // gr::digital::costas_loop_cc::sptr + typedef boost::shared_ptr<costas_loop_cc> sptr; + + /*! + * Make a Costas loop carrier recovery block. + * + * \param loop_bw internal 2nd order loop bandwidth (~ 2pi/100) + * \param order the loop order, either 2, 4, or 8 + */ + static sptr make(float loop_bw, int order); + }; + + } /* namespace digital */ +} /* namespace gr */ + +#endif /* INCLUDED_DIGITAL_COSTAS_LOOP_CC_H */ |