test_ldpc_sse2.c

This a framework to test new ideas in transmission technology. Actual development is a LDPC-coder in

/***************************************************************************
              test_ldpc_sse2.c  -  Module for testing optimized ldpc-codes
                            -------------------
    begin                :  2003
    authors              :  ysrini and ggupta
    emails               :  e-mail
 ***************************************************************************/

/***************************************************************************
                                 Changes
                                 -------
 date - name - description
 03/08/x - ysrini - start
 04/03/03 - ineiti - added a small comment

 **************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program 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 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

char desc[] =
"Description:\n"
"This test compares the speed of the non-optimized LDPC code with\n"
"the LDPC decoder implemented in SSE2. First it outputs the performances\n"
"of the non-optimized LDPC code for codes with rate 0.25, 0.5 and 0.75.\n"
"Each code is tested at 5 different SNR and the respective errors are\n"
"printed. At the end of each code-rate, the average time for decoding\n"
"is outputted.\n"
"After that, the optimized LDPC code is used for the same tests, that is,\n"
"rate 0.25, 0.5 and 0.75 at 5 different SNRs.\n"
"The speed-up should be between 5 and 8, depending on the code-rate.\n"
"If you have an old computer that doesn't support SSE2, this will of course\n"
"not work!\n\n";


#include "spc.h"
#include "std.h"
#include "chain.h"

#define DBG_LVL 4


struct chain_t *test_chain;

void *start_it( void *arg ){
  int i, sigma, sse2;
  swr_sdb_id rand, encode, mod, decode, block, send_data, 
             received_data, mafi_id, midamble;
  
  for ( sse2=1; sse2<=1; sse2++ ){
    // make one chain without sse2, the other with it
    if ( !sse2 ){
      PR( "\nSending with non-optimized LDPC-coder\n" );
      test_chain = swr_chain_create(
				 NEW_SPC_VAR( "random", rand ),
				 NEW_SPC_VAR( "test_data_send", send_data ),
				 NEW_SPC_VAR( "ldpc_encode", encode ),
				 NEW_SPC_VAR( "mapper", mod ),
				 NEW_SPC_VAR( "midamble", midamble ),
				 NEW_SPC( "rrc" ),
				 NEW_SPC_VAR( "block", block ),
				 NEW_SPC_VAR( "matched_filter", mafi_id ),
				 NEW_SPC_VAR( "ldpc_decode", decode ),
				 NEW_SPC_VAR( "test_data_rcv", received_data ),
				 CHAIN_END );
    } else {
      PR( "\nSending with SSE2-optimized LDPC-coder\n" );
      test_chain = swr_chain_create(
				 NEW_SPC_VAR( "random", rand ),
				 NEW_SPC_VAR( "test_data_send", send_data ),
				 NEW_SPC_VAR( "ldpc_encode_sse2", encode ),
				 NEW_SPC_VAR( "mapper", mod ),
				 NEW_SPC_VAR( "midamble", midamble ),
				 NEW_SPC( "rrc" ),
				 NEW_SPC_VAR( "block", block ),
				 NEW_SPC_VAR( "matched_filter", mafi_id ),
				 NEW_SPC_VAR( "ldpc_decode_sse2", decode ),
				 NEW_SPC_VAR( "test_data_rcv", received_data ),
				 CHAIN_END );
    }
    swr_conn_add(send_data, 1, received_data, 1);
  
    //  swr_sdb_set_config_int( midamble, "amplitude", 16384 );
    //  division by sqrt(2) is now done directly in the module
    //  swr_sdb_set_config_int( mod, "amplitude", 16384 );
    swr_sdb_set_config_int( decode, "iterations", 40 );
    swr_sdb_set_config_int( decode, "channel_type", 2 );

    // Here we take the channel_param from mafi. I.e.  a/variance
    // is not 1/15 but computed in ldpc_decode with the values taken from midamble_rcv 
    swr_sdb_set_config_int( decode, "mafi", mafi_id );

    for ( i=1; i<=3; i++ ){
      swr_sdb_set_config_int( encode, "ldpc_code_id", i );
      swr_sdb_set_config_int( decode, "ldpc_code_id", i );
      // Tell the random-module to produce a block of random-data which will
      // be propagated to the encode and decode module and finish in the sink.
      PR( "Sending with code %i\n", i );
  
      swr_sdb_clear_profile( decode );
      for ( sigma=100; sigma <= 900; sigma += 200 ){
        swr_sdb_set_config_double( block, "sigma", sigma );
        swr_sdb_set_config_int( received_data, "clear", 1 );
        swr_sdb_send_msg( rand, SUBS_MSG_USER, NULL, -1 );
        PR( "Transmitted %i bits and got %i errors with SNR =%g\n",
	  swr_sdb_get_stats_int( received_data, "total" ),
	  swr_sdb_get_stats_int( received_data, "error" ),
	  swr_sdb_get_stats_double(mafi_id, "snr") );
      }
      swr_sdb_show_profile( decode );
    }
    swr_chain_destroy( test_chain );
  }

  // After this call, the chain has been walked through
  usleep( 1000000 );

  return 0;
}

swr_spc_id_t spm_id;

struct thread start;
/**
 * This function is called upon "insmod" and is used to register the
 * different parts of the module to the SPM.
 */
int um_module_init(void){

  PR_CL( desc );
  test_chain = NULL;
  if ( swr_thread_init( &start, start_it, NULL ) < 0 ) goto first_no_stack;
  return 0;

first_no_stack:
  PR_DBG( 0, "Couldn't allocate stack\n" );
  return -1;
}

void um_module_exit( void ){

  swr_thread_free( &start, NULL );

}


module_init( um_module_init );
module_exit( um_module_exit );