midamble_send.c

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

/***************************************************************************
 *    send.c  - Software Radio midamble
 *                           -------------------
 *   begin                :  02/10/24
 *   authors              :  Linus Gasser
 *   emails               :  [e-mail]
 ***************************************************************************/

/***************************************************************************
 *                                Changes
 *                                -------
 * date - name - description
 * 02/10/24 - ineiti - begin
 * 03/01/23 - ineiti - cut 100 symbols at beginning and end
 * 03/03/13 - ineiti - cut is not needed anymore
 * 04/03/06 - ineiti - adjusted description
 *
 **************************************************************************/

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


/**
 *  A 3GPP midamble is implemented with a length of 256 symbols. It is
 * inserted in the middle of the received signal, so that it should reflect
 * most accuratly the changes from the channel.
 */

#include "spc.h"
#include "midamble.h"


#define DBG_LVL 0

typedef struct {
  // Type of the midamble. The following indexes are available:
  // 1 - 3GPP type 1 (192+64 = 256)
  // 2 - User Def    (512+32 = 544)
  // 3 - Midamble defined in Chinese WCDMA 128+16 = 144
  int type; // 3
  // The index of the user. Different users can send in the same
  // timeslot using different indexes.
  int index; // 0
  // Amplitude of the midamble
  int amplitude; // 32767
}
config_t;

typedef struct {}
stats_t;

typedef struct {}
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

  config->type = 3;
  config->index = 0;
  config->amplitude = 32767;

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


/*
 * 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 );

  port_in(0).size = port_out(0).size - midamble_get_length( config->type );

  // 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 );

  port_out(0).size = port_in(0).size + midamble_get_length( config->type );

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


/*
 * Every time modules from the outside change the value of a configuration parameter,
 * this function is called.
 */

int send_reconfig( swr_sdb_t *context ) {
  // Definition of variables - don't touch
  config_t *config;
  swr_sdb_get_config_struct( context->id, (void**)&config );

  if ( ( config->type >= NUM_MIDAMBLE_DEF ) ||
       ( config->type < 1 ) ) {
    PR_DBG( 0, "Midamble-type %i not available, only 1..%i are valuable types.\n",
            config->type, NUM_MIDAMBLE_DEF - 1 );
    config->type = NUM_MIDAMBLE_DEF - 1;
  }
  if ( config->index >= midamble_get_nbr_channels( config->type ) ) {
    PR_DBG( 0, "No midamble-index %i for midamble-type %i.\n",
            config->index, config->type );
    config->index = midamble_get_nbr_channels( config->type ) - 1;
  }
  if ( ( config->amplitude > 32767 ) ||
       ( config->amplitude < 0 ) ) {
    PR_DBG( 0, "Amplitude out of range...\n" );
    config->amplitude = 32767;
  }

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


/*
 * This is function that impements the `main method' of the class
 * Every calss has got just ONE method/working-mode.
 */
int send_pdata( swr_sdb_t *context ) {
  // Definition of variables - don't touch
  config_t *config;
  stats_t *stats;
  SYMBOL_COMPLEX *in, *out, *mid;
  //void *t;
  int type, index, amp;

  int i, j; //Selva - Counter

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

  swr_sdb_get_config_struct( context->id, (void**)&config );
  type = config->type;
  index = config->index;
  amp = config->amplitude;
  swr_sdb_free_config_struct( context->id, (void**)&config );

  // Copy the first half of the data
  memcpy( out, in, port_in(0).size / 2 * sizeof( SYMBOL_COMPLEX ) );
  // Copy the second half of the data
  memcpy( out + port_out(0).size - port_in(0).size / 2,
          in + port_in(0).size / 2,
          port_in(0).size / 2 * sizeof( SYMBOL_COMPLEX ) );
  mid = out + port_in(0).size / 2;
  midamble_write( type, mid, amp, index );

  //-------------------------------------------------------------//
  /* Added by Selvan*/
  /* Picks the midamble from the stream for display */
  /* Midamble to be used in MIMO */

  PR_DBG( 4, "Midamble-length: %i\n",
          midamble_get_length(type));
  for (i = 0; i < midamble_get_length(type) / 8; i++) {
    for ( j=0; j<8; j++ ) {
      PR_DBG_CL( 4, "%i,%i,",
                 mid[ 8 * i + j ].real,
                 mid[ 8 * i + j ].imag );
    }
    PR_DBG_CL( 4, "\n" );
  }

  swr_sdb_get_stats_struct( context->id, (void**)&stats );
  swr_sdb_free_stats_struct( context->id, (void**)&stats );

  return 0;
}


/*
 * This is the `destructor'.
 */
int send_finalize( swr_sdb_t *context ) {
  if ( sizeof( private_t ) > 0 ) {
    swr_free( context->private_data );
  }
  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, 3, 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,STRING128}( "name" );
   * UM_STATS_{INT,DOUBLE,STRING128}( "name" );
   */
  UM_CONFIG_INT( "type", PARAMETER_DEBUG );
  UM_CONFIG_INT( "index" );
  UM_CONFIG_INT( "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}, 0 );
   * UM_OUTPUT( SIG_{U8,SYMBOL_{S16,COMPLEX,MMX},SAMPLE_S12,S32}, 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_reconfigure       = send_reconfig;
  desc->fn_process_data      = send_pdata;
  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, "midamble" );
  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" );
  }
}