From 8edabae54b3b7c64180d734d4525a94e2a2d1ac8 Mon Sep 17 00:00:00 2001 From: Tom Rondeau Date: Wed, 18 May 2011 11:05:10 +0100 Subject: digital: set number of samps per symbol for the equalizer. Also, explicitly set the initial taps of the adaptive filter to 0+j0 --- gr-digital/lib/digital_cma_equalizer_cc.cc | 9 +++++---- gr-digital/lib/digital_cma_equalizer_cc.h | 7 ++++--- 2 files changed, 9 insertions(+), 7 deletions(-) (limited to 'gr-digital/lib') diff --git a/gr-digital/lib/digital_cma_equalizer_cc.cc b/gr-digital/lib/digital_cma_equalizer_cc.cc index 89f56c16f..113b50ab8 100644 --- a/gr-digital/lib/digital_cma_equalizer_cc.cc +++ b/gr-digital/lib/digital_cma_equalizer_cc.cc @@ -25,15 +25,16 @@ #endif #include +#include digital_cma_equalizer_cc_sptr -digital_make_cma_equalizer_cc(int num_taps, float modulus, float mu) +digital_make_cma_equalizer_cc(int num_taps, float modulus, float mu, int sps) { - return gnuradio::get_initial_sptr(new digital_cma_equalizer_cc(num_taps, modulus, mu)); + return gnuradio::get_initial_sptr(new digital_cma_equalizer_cc(num_taps, modulus, mu, sps)); } -digital_cma_equalizer_cc::digital_cma_equalizer_cc(int num_taps, float modulus, float mu) - : gr_adaptive_fir_ccc("cma_equalizer_cc", 1, std::vector(num_taps)) +digital_cma_equalizer_cc::digital_cma_equalizer_cc(int num_taps, float modulus, float mu, int sps) + : gr_adaptive_fir_ccc("cma_equalizer_cc", sps, std::vector(num_taps, gr_complex(0,0))) { set_modulus(modulus); set_gain(mu); diff --git a/gr-digital/lib/digital_cma_equalizer_cc.h b/gr-digital/lib/digital_cma_equalizer_cc.h index 54cba319c..ba94854d1 100644 --- a/gr-digital/lib/digital_cma_equalizer_cc.h +++ b/gr-digital/lib/digital_cma_equalizer_cc.h @@ -31,7 +31,7 @@ class digital_cma_equalizer_cc; typedef boost::shared_ptr digital_cma_equalizer_cc_sptr; digital_cma_equalizer_cc_sptr -digital_make_cma_equalizer_cc(int num_taps, float modulus, float mu); +digital_make_cma_equalizer_cc(int num_taps, float modulus, float mu, int sps); /*! * \brief Implements constant modulus adaptive filter on complex stream @@ -51,8 +51,9 @@ private: friend digital_cma_equalizer_cc_sptr digital_make_cma_equalizer_cc(int num_taps, float modulus, - float mu); - digital_cma_equalizer_cc(int num_taps, float modulus, float mu); + float mu, + int sps); + digital_cma_equalizer_cc(int num_taps, float modulus, float mu, int sps); protected: -- cgit From 7d1d1902c54dc8feeb5742592e28403011602708 Mon Sep 17 00:00:00 2001 From: Tom Rondeau Date: Fri, 3 Jun 2011 17:14:28 -0400 Subject: digital: adding an LMS decision-directed equalizer block. --- gr-digital/lib/Makefile.am | 2 + gr-digital/lib/digital_lms_dd_equalizer_cc.cc | 99 +++++++++++++++++++++++++++ gr-digital/lib/digital_lms_dd_equalizer_cc.h | 88 ++++++++++++++++++++++++ 3 files changed, 189 insertions(+) create mode 100644 gr-digital/lib/digital_lms_dd_equalizer_cc.cc create mode 100644 gr-digital/lib/digital_lms_dd_equalizer_cc.h (limited to 'gr-digital/lib') diff --git a/gr-digital/lib/Makefile.am b/gr-digital/lib/Makefile.am index 6f641b745..25a2b6f7f 100644 --- a/gr-digital/lib/Makefile.am +++ b/gr-digital/lib/Makefile.am @@ -28,6 +28,7 @@ grinclude_HEADERS = \ digital_constellation.h \ digital_costas_loop_cc.h \ digital_cma_equalizer_cc.h \ + digital_lms_dd_equalizer_cc.h \ digital_kurtotic_equalizer_cc.h lib_LTLIBRARIES = libgnuradio-digital.la @@ -36,6 +37,7 @@ libgnuradio_digital_la_SOURCES = \ digital_constellation.cc \ digital_costas_loop_cc.cc \ digital_cma_equalizer_cc.cc \ + digital_lms_dd_equalizer_cc.cc \ digital_kurtotic_equalizer_cc.cc libgnuradio_digital_la_LIBADD = \ diff --git a/gr-digital/lib/digital_lms_dd_equalizer_cc.cc b/gr-digital/lib/digital_lms_dd_equalizer_cc.cc new file mode 100644 index 000000000..05a51fa2c --- /dev/null +++ b/gr-digital/lib/digital_lms_dd_equalizer_cc.cc @@ -0,0 +1,99 @@ +/* -*- c++ -*- */ +/* + * Copyright 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 +#include +#include +#include + +digital_lms_dd_equalizer_cc_sptr +digital_make_lms_dd_equalizer_cc (float mu, int ntaps, + digital_constellation_sptr cnst) +{ + return gnuradio::get_initial_sptr(new digital_lms_dd_equalizer_cc (mu, ntaps, cnst)); +} + +digital_lms_dd_equalizer_cc::digital_lms_dd_equalizer_cc (float mu, int ntaps, + digital_constellation_sptr cnst) + : gr_sync_block ("lms_dd_equalizer_cc", + gr_make_io_signature (1, 1, sizeof (gr_complex)), + gr_make_io_signature (1, 1, sizeof (gr_complex))), + d_taps(ntaps), d_cnst(cnst) +{ + set_mu(mu); + + gr_zero_vector(d_taps); + d_taps [d_taps.size()/2] = 1; + + set_history(ntaps+1); +} + +float +digital_lms_dd_equalizer_cc::get_mu() +{ + return d_mu; +} + +void +digital_lms_dd_equalizer_cc::set_mu(float mu) +{ + if(mu < 0.0f || mu > 1.0f) { + throw std::out_of_range("digital_lms_dd_equalizer::set_mu: Gain value must in [0, 1]"); + } + else { + d_mu = mu; + } +} + +int +digital_lms_dd_equalizer_cc::work (int noutput_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]; + + gr_complex acc, decision, error; + + for(int i = 0; i < noutput_items; i++) { + acc = 0; + + // Compute output + for (size_t j=0; j < d_taps.size(); j++) + acc += in[i+j] * conj(d_taps[j]); + + d_cnst->map_to_points(d_cnst->decision_maker(&acc), &decision); + error = decision - acc; + + // Update taps + for (size_t j=0; j < d_taps.size(); j++) + d_taps[j] += d_mu * conj(error) * in[i+j]; + + out[i] = acc; // Output decision + } + + return noutput_items; +} diff --git a/gr-digital/lib/digital_lms_dd_equalizer_cc.h b/gr-digital/lib/digital_lms_dd_equalizer_cc.h new file mode 100644 index 000000000..f33b5fc5c --- /dev/null +++ b/gr-digital/lib/digital_lms_dd_equalizer_cc.h @@ -0,0 +1,88 @@ +/* -*- c++ -*- */ +/* + * Copyright 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. + */ + +#ifndef INCLUDED_DIGITAL_LMS_DD_EQUALIZER_CC_H +#define INCLUDED_DIGITAL_LMS_DD_EQUALIZER_CC_H + +#include +#include + +class digital_lms_dd_equalizer_cc; +typedef boost::shared_ptr digital_lms_dd_equalizer_cc_sptr; + +digital_lms_dd_equalizer_cc_sptr digital_make_lms_dd_equalizer_cc (float mu, int ntaps, + digital_constellation_sptr cnst); + +/*! + * \brief Least-Mean-Square Decision Directed Equalizer (complex in/out) + * \ingroup eq_blk + * + * This block implements an LMS-based decision-directed equalizer. + * It uses a set of weights, w, to correlate against the inputs, u, + * and a decisions is then made from this output. The error + * in the decision is used to update teh weight vector. + * + * y[n] = conj(w[n]) u[n] + * d[n] = decision(y[n]) + * e[n] = d[n] - y[n] + * w[n+1] = w[n] + mu u[n] conj(e[n]) + * + * Where mu is a gain value (between 0 and 1 and usualy small, + * around 0.01 - 0.1. + * + * This block uses the digital_constellation object for making + * the decision from y[n]. Create the constellation object for + * whatever constellation is to be used and pass in the object. + * In Python, you can use something like: + * self.constellation = digital.constellation_qpsk() + * To create a QPSK constellation (see the digital_constellation + * block for more details as to what constellations are available + * or how to create your own). You then pass the object to this + * block as an sptr, or using "self.constellation.base()". + * + * The theory for this algorithm can be found in Chapter 9 of: + * S. Haykin, Adaptive Filter Theory, Upper Saddle River, NJ: + * Prentice Hall, 1996. + * + */ +class digital_lms_dd_equalizer_cc : public gr_sync_block +{ +private: + friend digital_lms_dd_equalizer_cc_sptr digital_make_lms_dd_equalizer_cc (float mu, int ntaps, + digital_constellation_sptr cnst); + + float d_mu; + std::vector d_taps; + digital_constellation_sptr d_cnst; + + digital_lms_dd_equalizer_cc (float mu, int ntaps, + digital_constellation_sptr cnst); + +public: + float get_mu(); + void set_mu(float mu); + int work (int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items); +}; + +#endif -- cgit From 6ffd5d207483b05b0137608a428563b3cead3d26 Mon Sep 17 00:00:00 2001 From: Tom Rondeau Date: Fri, 3 Jun 2011 17:56:27 -0400 Subject: digital: fixing 8psk constellation object to properly slice. --- gr-digital/lib/digital_constellation.cc | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) (limited to 'gr-digital/lib') diff --git a/gr-digital/lib/digital_constellation.cc b/gr-digital/lib/digital_constellation.cc index bfed84320..edf0bda22 100644 --- a/gr-digital/lib/digital_constellation.cc +++ b/gr-digital/lib/digital_constellation.cc @@ -433,7 +433,7 @@ digital_constellation_8psk::digital_constellation_8psk () d_constellation.resize(8); // Gray-coded d_constellation[0] = gr_complex(cos( 1*angle), sin( 1*angle)); - d_constellation[1] = gr_complex(cos( 7*angle), sin( 3*angle)); + d_constellation[1] = gr_complex(cos( 7*angle), sin( 7*angle)); d_constellation[2] = gr_complex(cos(15*angle), sin(15*angle)); d_constellation[3] = gr_complex(cos( 9*angle), sin( 9*angle)); d_constellation[4] = gr_complex(cos( 3*angle), sin( 3*angle)); @@ -448,17 +448,17 @@ digital_constellation_8psk::digital_constellation_8psk () unsigned int digital_constellation_8psk::decision_maker(const gr_complex *sample) { - // Real component determines small bit. - // Imag component determines big bit. - return 2*(imag(*sample)>0) + (real(*sample)>0); + unsigned int ret = 0; - unsigned int real, imag; - imag = 2*(sample->imag()<=0); - real = (sample->real()<=0); - if(abs(sample->real()) >= abs(sample->imag())) { - return 0 + imag + real; - } - else { - return 4 + imag + real; - } + float re = sample->real(); + float im = sample->imag(); + + if(fabsf(re) <= fabsf(im)) + ret = 4; + if(re <= 0) + ret |= 1; + if(im <= 0) + ret |= 2; + + return ret; } -- cgit From 7293ac44d02280407f2b8dfd265eafe33178086f Mon Sep 17 00:00:00 2001 From: Tom Rondeau Date: Fri, 3 Jun 2011 17:57:32 -0400 Subject: digital: fixing comments on LMS DD equalizer --- gr-digital/lib/digital_lms_dd_equalizer_cc.cc | 2 +- gr-digital/lib/digital_lms_dd_equalizer_cc.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'gr-digital/lib') diff --git a/gr-digital/lib/digital_lms_dd_equalizer_cc.cc b/gr-digital/lib/digital_lms_dd_equalizer_cc.cc index 05a51fa2c..77b8ac579 100644 --- a/gr-digital/lib/digital_lms_dd_equalizer_cc.cc +++ b/gr-digital/lib/digital_lms_dd_equalizer_cc.cc @@ -92,7 +92,7 @@ digital_lms_dd_equalizer_cc::work (int noutput_items, for (size_t j=0; j < d_taps.size(); j++) d_taps[j] += d_mu * conj(error) * in[i+j]; - out[i] = acc; // Output decision + out[i] = acc; } return noutput_items; diff --git a/gr-digital/lib/digital_lms_dd_equalizer_cc.h b/gr-digital/lib/digital_lms_dd_equalizer_cc.h index f33b5fc5c..12c2ecc13 100644 --- a/gr-digital/lib/digital_lms_dd_equalizer_cc.h +++ b/gr-digital/lib/digital_lms_dd_equalizer_cc.h @@ -47,7 +47,7 @@ digital_lms_dd_equalizer_cc_sptr digital_make_lms_dd_equalizer_cc (float mu, int * w[n+1] = w[n] + mu u[n] conj(e[n]) * * Where mu is a gain value (between 0 and 1 and usualy small, - * around 0.01 - 0.1. + * around 0.001 - 0.01. * * This block uses the digital_constellation object for making * the decision from y[n]. Create the constellation object for -- cgit From 23ee6269df6f139ef6b85e7f404d452c10bb63a8 Mon Sep 17 00:00:00 2001 From: Tom Rondeau Date: Mon, 6 Jun 2011 11:35:28 -0400 Subject: digital: formatting CMA code; adding get_ functions and renaming things for consistency. --- gr-digital/lib/digital_cma_equalizer_cc.cc | 10 ++++++---- gr-digital/lib/digital_cma_equalizer_cc.h | 15 +++++++++++++-- 2 files changed, 19 insertions(+), 6 deletions(-) (limited to 'gr-digital/lib') diff --git a/gr-digital/lib/digital_cma_equalizer_cc.cc b/gr-digital/lib/digital_cma_equalizer_cc.cc index 113b50ab8..c6c46c2d8 100644 --- a/gr-digital/lib/digital_cma_equalizer_cc.cc +++ b/gr-digital/lib/digital_cma_equalizer_cc.cc @@ -30,15 +30,17 @@ digital_cma_equalizer_cc_sptr digital_make_cma_equalizer_cc(int num_taps, float modulus, float mu, int sps) { - return gnuradio::get_initial_sptr(new digital_cma_equalizer_cc(num_taps, modulus, mu, sps)); + return gnuradio::get_initial_sptr(new digital_cma_equalizer_cc(num_taps, modulus, + mu, sps)); } -digital_cma_equalizer_cc::digital_cma_equalizer_cc(int num_taps, float modulus, float mu, int sps) - : gr_adaptive_fir_ccc("cma_equalizer_cc", sps, std::vector(num_taps, gr_complex(0,0))) +digital_cma_equalizer_cc::digital_cma_equalizer_cc(int num_taps, float modulus, + float mu, int sps) + : gr_adaptive_fir_ccc("cma_equalizer_cc", sps, + std::vector(num_taps, gr_complex(0,0))) { set_modulus(modulus); set_gain(mu); if (num_taps > 0) d_taps[0] = 1.0; } - diff --git a/gr-digital/lib/digital_cma_equalizer_cc.h b/gr-digital/lib/digital_cma_equalizer_cc.h index ba94854d1..0dd99debd 100644 --- a/gr-digital/lib/digital_cma_equalizer_cc.h +++ b/gr-digital/lib/digital_cma_equalizer_cc.h @@ -72,12 +72,23 @@ protected: } public: + float get_gain() + { + return d_mu; + } + void set_gain(float mu) { - if(mu < 0) - throw std::out_of_range("digital_cma_equalizer::set_gain: Gain value must be >= 0"); + if(mu < 0.0f || mu > 1.0f) { + throw std::out_of_range("digital_cma_equalizer::set_gain: Gain value must be in [0,1]"); + } d_mu = mu; } + + float get_modulus() + { + return d_modulus; + } void set_modulus(float mod) { -- cgit From 86553ec410b1074bc4258b22027c5d31443d12ec Mon Sep 17 00:00:00 2001 From: Tom Rondeau Date: Mon, 6 Jun 2011 11:36:24 -0400 Subject: digital: converting LMS algorithm to use the gr_adaptive_filter structure and making naming consistent (so CMA and LMS look and behave similary with different error and upate functions). --- gr-digital/lib/digital_lms_dd_equalizer_cc.cc | 46 +++++++++--------------- gr-digital/lib/digital_lms_dd_equalizer_cc.h | 50 +++++++++++++++++++++------ 2 files changed, 55 insertions(+), 41 deletions(-) (limited to 'gr-digital/lib') diff --git a/gr-digital/lib/digital_lms_dd_equalizer_cc.cc b/gr-digital/lib/digital_lms_dd_equalizer_cc.cc index 77b8ac579..e2c2f16f2 100644 --- a/gr-digital/lib/digital_lms_dd_equalizer_cc.cc +++ b/gr-digital/lib/digital_lms_dd_equalizer_cc.cc @@ -30,44 +30,29 @@ #include digital_lms_dd_equalizer_cc_sptr -digital_make_lms_dd_equalizer_cc (float mu, int ntaps, - digital_constellation_sptr cnst) +digital_make_lms_dd_equalizer_cc(int num_taps, float mu, int sps, + digital_constellation_sptr cnst) { - return gnuradio::get_initial_sptr(new digital_lms_dd_equalizer_cc (mu, ntaps, cnst)); + return gnuradio::get_initial_sptr(new digital_lms_dd_equalizer_cc(num_taps, mu, + sps, cnst)); } -digital_lms_dd_equalizer_cc::digital_lms_dd_equalizer_cc (float mu, int ntaps, - digital_constellation_sptr cnst) - : gr_sync_block ("lms_dd_equalizer_cc", - gr_make_io_signature (1, 1, sizeof (gr_complex)), - gr_make_io_signature (1, 1, sizeof (gr_complex))), - d_taps(ntaps), d_cnst(cnst) +digital_lms_dd_equalizer_cc::digital_lms_dd_equalizer_cc(int num_taps, float mu, + int sps, + digital_constellation_sptr cnst) + : gr_adaptive_fir_ccc("lms_dd_equalizer_cc", sps, + std::vector(num_taps, gr_complex(0,0))), + d_taps(num_taps), d_cnst(cnst) { - set_mu(mu); - - gr_zero_vector(d_taps); - d_taps [d_taps.size()/2] = 1; - - set_history(ntaps+1); + set_gain(mu); + if (num_taps > 0) + d_taps[num_taps/2] = 1.0; } -float -digital_lms_dd_equalizer_cc::get_mu() -{ - return d_mu; -} -void -digital_lms_dd_equalizer_cc::set_mu(float mu) -{ - if(mu < 0.0f || mu > 1.0f) { - throw std::out_of_range("digital_lms_dd_equalizer::set_mu: Gain value must in [0, 1]"); - } - else { - d_mu = mu; - } -} + +/* int digital_lms_dd_equalizer_cc::work (int noutput_items, gr_vector_const_void_star &input_items, @@ -97,3 +82,4 @@ digital_lms_dd_equalizer_cc::work (int noutput_items, return noutput_items; } +*/ diff --git a/gr-digital/lib/digital_lms_dd_equalizer_cc.h b/gr-digital/lib/digital_lms_dd_equalizer_cc.h index 12c2ecc13..e3ad4bf4a 100644 --- a/gr-digital/lib/digital_lms_dd_equalizer_cc.h +++ b/gr-digital/lib/digital_lms_dd_equalizer_cc.h @@ -23,15 +23,16 @@ #ifndef INCLUDED_DIGITAL_LMS_DD_EQUALIZER_CC_H #define INCLUDED_DIGITAL_LMS_DD_EQUALIZER_CC_H -#include +#include #include class digital_lms_dd_equalizer_cc; typedef boost::shared_ptr digital_lms_dd_equalizer_cc_sptr; -digital_lms_dd_equalizer_cc_sptr digital_make_lms_dd_equalizer_cc (float mu, int ntaps, +digital_lms_dd_equalizer_cc_sptr digital_make_lms_dd_equalizer_cc (int num_taps, + float mu, int sps, digital_constellation_sptr cnst); - + /*! * \brief Least-Mean-Square Decision Directed Equalizer (complex in/out) * \ingroup eq_blk @@ -64,25 +65,52 @@ digital_lms_dd_equalizer_cc_sptr digital_make_lms_dd_equalizer_cc (float mu, int * Prentice Hall, 1996. * */ -class digital_lms_dd_equalizer_cc : public gr_sync_block +class digital_lms_dd_equalizer_cc : public gr_adaptive_fir_ccc { private: - friend digital_lms_dd_equalizer_cc_sptr digital_make_lms_dd_equalizer_cc (float mu, int ntaps, + friend digital_lms_dd_equalizer_cc_sptr digital_make_lms_dd_equalizer_cc (int num_taps, + float mu, int sps, digital_constellation_sptr cnst); float d_mu; std::vector d_taps; digital_constellation_sptr d_cnst; - digital_lms_dd_equalizer_cc (float mu, int ntaps, + digital_lms_dd_equalizer_cc (int num_taps, + float mu, int sps, digital_constellation_sptr cnst); +protected: + + virtual gr_complex error(const gr_complex &out) + { + gr_complex decision, error; + d_cnst->map_to_points(d_cnst->decision_maker(&out), &decision); + error = decision - out; + return error; + } + + virtual void update_tap(gr_complex &tap, const gr_complex &in) + { + tap += d_mu*conj(in)*d_error; + } + public: - float get_mu(); - void set_mu(float mu); - int work (int noutput_items, - gr_vector_const_void_star &input_items, - gr_vector_void_star &output_items); + float get_gain() + { + return d_mu; + } + + void set_gain(float mu) + { + if(mu < 0.0f || mu > 1.0f) { + throw std::out_of_range("digital_lms_dd_equalizer::set_mu: Gain value must in [0, 1]"); + } + else { + d_mu = mu; + } + } + }; #endif -- cgit