rrc_complex_send.c

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

/***************************************************************************
 *    rrc_complex_send.c  -  Shapes the signal with an rrc
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/


/**
 * Takes a signal and upsamples it by a factor of 2, putting an RRC with
 * roll-off factor of 0.22 on it.
 */

#include "spc.h"
#include "rrcs.h"


#define DBG_LVL 0


// ADD_HERE, int, double, char[128], void*
// BEFORE each declaration, write a short description.
// ON THE SAME LINE as the declaration, write the default value
// Example:
// {
//   // size of the input in bytes
//   int size; // 2560
// }
typedef struct {
  // Which of the rrcs to use
  int rrc_index; // 0
  // What amplitude
  double amplitude; // 1
}
config_t;

// ADD_HERE, int, double, char[128], void*
// for the rest, the same definition as the confit_t is valid.
typedef struct {
}
stats_t;

// ADD HERE anything you want!
typedef struct {
  int rrc_len;
  double rrc[MAX_RRC_LEN];
  double rrc_amp;
}
private_t;


/*
 * The initialisation function, or constructor, 
 * is called the first time this module is instantiated.
 */

int send_init( swr_sdb_t *context ) {
  // Begin system-definitions {
  config_t *config;
  stats_t *stats;
  MOD_INC_USE_COUNT;
  if ( sizeof( private_t ) > 0 )
    context->private_data = swr_malloc( sizeof( private_t ) );
  swr_sdb_get_config_struct( context->id, (void**)&config );
  swr_sdb_get_stats_struct( context->id, (void**)&stats );
  // } End of system-definitions

  /**
   * Put your initialisation here. All parameters you define in config_t,
   * stats_t and private_t can be accessed through config->, stats-> and
   * private-> respectively
   * ADD HERE
   */
  config->rrc_index = 0;
  config->amplitude = 1;

  // Begin system-definitions
  swr_sdb_free_stats_struct( context->id, (void**)&stats );
  swr_sdb_free_config_struct( context->id, (void**)&config );
  return 0;
  // End system-definitions
}


int send_reconfig( swr_sdb_t *context ) {
  config_t *config;
  int i;

  swr_sdb_get_config_struct( context->id, (void**)&config );

  if ( ( config->rrc_index < NUM_OF_RRCS ) && ( config->rrc_index >= 0 ) ){
    private->rrc_len = *rrcs[ config->rrc_index ];
    private->rrc_amp = 0;
    for ( i=0; i<private->rrc_len; i++ ){
      private->rrc[i] = rrcs[ config->rrc_index ][ i + 1 ];
      private->rrc_amp += abs( private->rrc[ i ] );
    }
    if ( config->amplitude > 0 ){
      private->rrc_amp /= config->amplitude;
    }
  }

  swr_sdb_free_config_struct( context->id, (void**)&config );
  return 0;
}


/*
 * To configure the inputs
 * this is called when the output-sizes change.
 */
int send_configure_inputs( swr_sdb_t *context ) {
  // Definition of variables - don't touch
  config_t *config;
  swr_sdb_get_config_struct( context->id, (void**)&config );

  size_in(0) = size_out(0) / 2;

  // Definition - don't touch
  swr_sdb_free_config_struct( context->id, (void**)&config );
  return 0;
}


/*
 * To configure the outputs
 * this is called when the input-sizes change
 */
int send_configure_outputs( swr_sdb_t *context ) {
  // Definition of variables - don't touch
  config_t *config;
  swr_sdb_get_config_struct( context->id, (void**)&config );

  size_out(0) = size_in(0) * 2;

  // Definition - don't touch
  swr_sdb_free_config_struct( context->id, (void**)&config );
  return 0;
}


#define CPLX(c) ((c).real + I*(c).imag)
#define SYMB(re,im) (SYMBOL_COMPLEX){ re, im }
#define MULT(cplx,r) SYMB( (cplx).real*(r), (cplx).imag*(r) )
#define ADD(c1,c2) SYMB( (c1).real+(c2).real, (c1).imag+(c2).imag )
/*
 * This is the function that implements the `main method' of the class
 * Every class has got just ONE method/working-mode.
 */
int send_pdata( swr_sdb_t *context ) {
  // Definition of variables - don't touch
  SYMBOL_COMPLEX *in, *out, *buf;
  int i, j, mp = private->rrc_len, buflen;

  in = buffer_in( 0 );
  out = buffer_out( 0 );

#if 1
  buflen = sizeof( SYMBOL_COMPLEX ) * ( size_out( 0 ) + 4 * mp );
  buf = swr_malloc( buflen );

  memset( buf, 0, buflen );
  for ( i=0; i<size_in(0); i++ ){
    buf[ 2 * i + 3 * mp / 2 ] = in[ i ];
  }

  // convolution
  memset( out, 0, sizeof( SYMBOL_COMPLEX ) * size_out( 0 ) );
  for ( i=0; i < size_out(0) + 2 * mp - 1; i++ ){
    double complex o = 0;
    for ( j=0; j<mp; j++ ){
      o += CPLX( buf[ i + j ] ) * private->rrc[ j ];
    }
    o /= private->rrc_amp;
    out[ i - mp ] = SYMB( creal( o ), cimag( o ) );
  }
  swr_free( buf );

#else
  memset( out, 0, sizeof( SYMBOL_COMPLEX ) * size_out( 0 ) );
  for ( i=0; i < size_in(0); i++ ){
    out[ 2*i ] = in[ i ];
  }
#endif

  return(0);
}

/*
 * This is the `destructor'.
 */
int send_finalize( swr_sdb_t *context ) {
  if ( sizeof( private_t ) > 0 )
    swr_free( private );
  MOD_DEC_USE_COUNT;
  return 0;
}


/*
 * This function is called upon "insmod" and is used to register the
 * different parts of the module to the SPM.
 */
swr_spc_id_t send_id;
int send_module_init(void) {
  swr_spc_desc_t *desc;

  /**
   * Get a description-part from SPM
   * Give the following parameters:
   * Input-ports, output-ports, config-params, stat-params
   */
  desc = swr_spc_get_new_desc( 1, 1, 2, 0 );
  if ( !desc ) {
    PR_DBG( 0, "Can't initialise the module. This is BAD!\n" );
    return -1;
  }

  /**
   * Define the different parts of config and stats. You have to define
   * them in the same order as they appear in the structures. The names
   * can be freely chosen.
   *
   * UM_CONFIG_{INT,DOUBLE,DOUBLE_COMPLEX,STRING128,POINTER}( "name" );
   * UM_STATS_{INT,DOUBLE,DOUBLE_COMPLEX,STRING128,POINTER,BLOCK,IMAGE}( "name" );
   */
  UM_CONFIG_INT( "rrc_index" );
  UM_CONFIG_DOUBLE( "amplitude" );
 
  /**
   * The in- and outputs have also to be defined in the right order. First
   * port first. The additional flag is not used yet, but it will...
   *
   * UM_INPUT( SIG_{U8,SYMBOL_{S16,COMPLEX,MMX},SAMPLE_S12,S32,DOUBLE_{,COMPLEX}}, 0 );
   * UM_OUTPUT( SIG_{U8,SYMBOL_{S16,COMPLEX,MMX},SAMPLE_S12,S32,DOUBLE_{,COMPLEX}}, 0 );
   */
  UM_INPUT( SIG_SYMBOL_COMPLEX, 0 );
  UM_OUTPUT( SIG_SYMBOL_COMPLEX, 0 );

  // Initialise the callback-functions. Delete the ones you don't use
  desc->fn_init              = send_init;
  desc->fn_process_data      = send_pdata;
  desc->fn_reconfigure       = send_reconfig;
  desc->fn_configure_inputs  = send_configure_inputs;
  desc->fn_configure_outputs = send_configure_outputs;
  desc->fn_finalize          = send_finalize;

  // And register the module in the SPM. Change the name!
  send_id = swr_cdb_register_spc( &desc, "rrc_complex_send" );
  if ( send_id == SWR_SPM_INVALID_ID ) {
    swr_spc_free_desc( desc );
    PR_DBG( 0, "Couldn't register the module!\n" );
    return 1;
  }
  PR_DBG( 4, "Ready\n" );
  return 0;
}


/*
 * This is called upon rmmod
 */
void send_module_exit( void ) {
  PR_DBG( 4, "Freeing id: %i\n", send_id );
  if ( swr_cdb_unregister_spc( send_id ) < 0 ) {
    PR_DBG( 0, "Still in use somewhere\n" );
  }
}