diff options
author | Tom Rondeau <trondeau@vt.edu> | 2012-08-09 21:30:50 -0400 |
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committer | Tom Rondeau <trondeau@vt.edu> | 2012-08-09 21:30:50 -0400 |
commit | 4fcfe4fc01207dfaa941c6b334a7d8e40ccfcb81 (patch) | |
tree | 9755e357958abd54fff2cfb0ae0207084d859536 /gr-digital/lib/digital_clock_recovery_mm_cc.cc | |
parent | 45502b80d28e2051f5f7780e0c386147f0976798 (diff) |
digital: converted clock recovery MM loops (cc and ff).
Diffstat (limited to 'gr-digital/lib/digital_clock_recovery_mm_cc.cc')
-rw-r--r-- | gr-digital/lib/digital_clock_recovery_mm_cc.cc | 217 |
1 files changed, 0 insertions, 217 deletions
diff --git a/gr-digital/lib/digital_clock_recovery_mm_cc.cc b/gr-digital/lib/digital_clock_recovery_mm_cc.cc deleted file mode 100644 index 198eb4b890..0000000000 --- a/gr-digital/lib/digital_clock_recovery_mm_cc.cc +++ /dev/null @@ -1,217 +0,0 @@ -/* -*- c++ -*- */ -/* - * Copyright 2005,2006,2010,2011 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. - */ - -#ifdef HAVE_CONFIG_H -#include "config.h" -#endif - -#include <gr_io_signature.h> -#include <gr_prefs.h> -#include <digital_clock_recovery_mm_cc.h> -#include <gri_mmse_fir_interpolator_cc.h> -#include <stdexcept> -#include <cstdio> - - -// Public constructor -static const int FUDGE = 16; - -digital_clock_recovery_mm_cc_sptr -digital_make_clock_recovery_mm_cc(float omega, float gain_omega, - float mu, float gain_mu, - float omega_relative_limit) -{ - return gnuradio::get_initial_sptr(new digital_clock_recovery_mm_cc (omega, - gain_omega, - mu, - gain_mu, - omega_relative_limit)); -} - -digital_clock_recovery_mm_cc::digital_clock_recovery_mm_cc (float omega, float gain_omega, - float mu, float gain_mu, - float omega_relative_limit) - : gr_block ("clock_recovery_mm_cc", - gr_make_io_signature (1, 1, sizeof (gr_complex)), - gr_make_io_signature2 (1, 2, sizeof (gr_complex), sizeof(float))), - d_mu (mu), d_omega(omega), d_gain_omega(gain_omega), - d_omega_relative_limit(omega_relative_limit), - d_gain_mu(gain_mu), d_last_sample(0), d_interp(new gri_mmse_fir_interpolator_cc()), - d_verbose(gr_prefs::singleton()->get_bool("clock_recovery_mm_cc", "verbose", false)), - d_p_2T(0), d_p_1T(0), d_p_0T(0), d_c_2T(0), d_c_1T(0), d_c_0T(0) -{ - if (omega <= 0.0) - throw std::out_of_range ("clock rate must be > 0"); - if (gain_mu < 0 || gain_omega < 0) - throw std::out_of_range ("Gains must be non-negative"); - - set_omega(omega); // also sets min and max omega - set_relative_rate (1.0 / omega); - set_history(3); // ensure 2 extra input sample is available -} - -digital_clock_recovery_mm_cc::~digital_clock_recovery_mm_cc () -{ - delete d_interp; -} - -void -digital_clock_recovery_mm_cc::forecast(int noutput_items, gr_vector_int &ninput_items_required) -{ - 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()) + FUDGE; -} - -gr_complex -digital_clock_recovery_mm_cc::slicer_0deg (gr_complex sample) -{ - float real=0, imag=0; - - if(sample.real() > 0) - real = 1; - if(sample.imag() > 0) - imag = 1; - return gr_complex(real,imag); -} - -gr_complex -digital_clock_recovery_mm_cc::slicer_45deg (gr_complex sample) -{ - float real= -1, imag = -1; - if(sample.real() > 0) - real=1; - if(sample.imag() > 0) - imag = 1; - return gr_complex(real,imag); -} - -/* - Modified Mueller and Muller clock recovery circuit - Based: - G. R. Danesfahani, T.G. Jeans, "Optimisation of modified Mueller and Muller - algorithm," Electronics Letters, Vol. 31, no. 13, 22 June 1995, pp. 1032 - 1033. -*/ - -int -digital_clock_recovery_mm_cc::general_work (int noutput_items, - gr_vector_int &ninput_items, - gr_vector_const_void_star &input_items, - gr_vector_void_star &output_items) -{ - const gr_complex *in = (const gr_complex *) input_items[0]; - gr_complex *out = (gr_complex *) output_items[0]; - float *foptr = (float *) output_items[1]; - - bool write_foptr = output_items.size() >= 2; - - int ii = 0; // input index - int oo = 0; // output index - int ni = ninput_items[0] - d_interp->ntaps() - FUDGE; // don't use more input than this - - assert(d_mu >= 0.0); - assert(d_mu <= 1.0); - - float mm_val=0; - gr_complex u, x, y; - - // This loop writes the error to the second output, if it exists - if (write_foptr) { - while(oo < noutput_items && ii < ni) { - d_p_2T = d_p_1T; - d_p_1T = d_p_0T; - d_p_0T = d_interp->interpolate (&in[ii], d_mu); - - d_c_2T = d_c_1T; - d_c_1T = d_c_0T; - d_c_0T = slicer_0deg(d_p_0T); - - x = (d_c_0T - d_c_2T) * conj(d_p_1T); - y = (d_p_0T - d_p_2T) * conj(d_c_1T); - u = y - x; - mm_val = u.real(); - out[oo++] = d_p_0T; - - // limit mm_val - mm_val = gr_branchless_clip(mm_val,4.0); - d_omega = d_omega + d_gain_omega * mm_val; - d_omega = d_omega_mid + gr_branchless_clip(d_omega-d_omega_mid, d_omega_relative_limit); // make sure we don't walk away - - d_mu = d_mu + d_omega + d_gain_mu * mm_val; - ii += (int)floor(d_mu); - d_mu -= floor(d_mu); - - // write the error signal to the second output - foptr[oo-1] = mm_val; - - if (ii < 0) // clamp it. This should only happen with bogus input - ii = 0; - } - } - // This loop does not write to the second output (ugly, but faster) - else { - while(oo < noutput_items && ii < ni) { - d_p_2T = d_p_1T; - d_p_1T = d_p_0T; - d_p_0T = d_interp->interpolate (&in[ii], d_mu); - - d_c_2T = d_c_1T; - d_c_1T = d_c_0T; - d_c_0T = slicer_0deg(d_p_0T); - - x = (d_c_0T - d_c_2T) * conj(d_p_1T); - y = (d_p_0T - d_p_2T) * conj(d_c_1T); - u = y - x; - mm_val = u.real(); - out[oo++] = d_p_0T; - - // limit mm_val - mm_val = gr_branchless_clip(mm_val,1.0); - - d_omega = d_omega + d_gain_omega * mm_val; - d_omega = d_omega_mid + gr_branchless_clip(d_omega-d_omega_mid, d_omega_relative_limit); // make sure we don't walk away - - d_mu = d_mu + d_omega + d_gain_mu * mm_val; - ii += (int)floor(d_mu); - d_mu -= floor(d_mu); - - if(d_verbose) { - printf("%f\t%f\n", d_omega, d_mu); - } - - if (ii < 0) // clamp it. This should only happen with bogus input - ii = 0; - } - } - - if (ii > 0){ - if (ii > ninput_items[0]){ - fprintf(stderr, "gr_clock_recovery_mm_cc: ii > ninput_items[0] (%d > %d)\n", - ii, ninput_items[0]); - assert(0); - } - consume_each (ii); - } - - return oo; -} |