/**\

• Parts (c) 2001-2003 Technische Universitaet Darmstadt, Institut fuer
• Nachrichtentechnik Fachbereich Uebertragungstechnik
• Parts Copyright (c) 2003, 2004 Fraunhofer IIS, Erlangen, Germany
• Parts Copyright (c) 2004 - 2009 British Broadcasting Corporation
• Originally written by:
• Volker Fischer, Alexander Kurpiers
• Additional contributions by:
• Stephane Fillod, Andrea Russo, Julian Cable, Andrew Murphy, Oliver Haffenden,
• Tomi Manninen, Robert Kesterson

• ---

• 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.
• This program 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
• this program; if not, write to the Free Software Foundation, Inc.,
• 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

• ******/

Introduction

Digital Radio Mondiale (DRM) is the digital radio standard for the long-, medium- and short-wave bands. The system is defined by ES 201 980 which is freely downloadable from the European Telecommunications Standards Insitute (ETSI). The system was designed by a consortium in co-operation with the International Telecommunication Union (ITU). It offers radio stations and new service providers access to the multimedia age with small bit rates for large target areas and long distances.

For more information, visit www.drm.org.

The bandwidth of a DRM bandpass signal is less than 20 kHz and the number of carriers used in the OFDM-modulation is relatively small (max. 460). These features motivate a real-time software implementation of a DRM-receiver on a conventional personal computer (PC) using the sound card as the input and output device. A long, medium and short wave front-end with an intermediate frequency (IF) between 5 kHz and 15 kHz is used to receive the DRM signal. Any commercial front-end with an IF of 455 kHz should be usable by adding a 455 kHz to 12 kHz adaptor (asumed the receiver bandwith is sufficient for a DRM signal). Documentation of receiver modifications for DRM reception can be found at www.drmrx.org.

With this software project we intend to implement a working software receiver with, at least, the basic features. Since this project is created at a university and the fundamental idea of such an institution is to teach and stimulate the creativity, this source-code is free under the GNU-General Public License (GPL). Dream is a development project which uses the open source model to improve DRM technology. The main aim of this project is to implement and test new research results on an existing system, whereby the synchronization and channel estimation is of special interest.

The programming-language is C++. Start of the project was June 2001. The software runs on Microsoft Windows, Linux and OSX

Although this software is distributed as free software under the terms of the GPL this does not mean that its use is free of rights of others. The use may infringe third party IP and thus may not be legal in some countries.

The intended audience of the Dream software are people who are interested in how to decode a DRM stream and want to learn from the algorithms used in this software and people who want to help us improving the performance of the receiver and the source code.

Homepage: http://drm.sourceforge.net

Dream code Code-Style definitions

GENERAL CONVENTIONS

• tab size: 4 (taps are NOT replaced by spaces)
• maximum line width: 80 characters

USAGE OF BRACKETS

• if, while, do commands:

[command1] { / Code 1 /

[command2]
{
    /* Code 2 (more than one line) */
}

}

• exception: if only one line of code, do not use brackets:

[command1] / Code (only one line) /

• switch command:

switch ([variable]) { case [condition1]: / Code for condition 1 / break;

case [condition2]: / Code for condition 2 / break; }

COMMENTS

• Comments start with capital letters
• regular comments shall be placed in front of the command:

/ This is the comment for the next line / [command]

• short comments can be placed right after the command:

[command] / Short comment (1 space between command and comment) /

• long comments (e.g. a function description):

/ This is a long description for the following section of code. The text is written with increased indent whereby the indent is realized with tabs. /

• sections comments (there are always two empty lines before a section):

/**\

• This is a section * ******/

/* This is a subsection ***/

/ This is a subsubsection -------------------------------------------------- /

PREPROCESSOR DIRECTIVES

• insert spaces if preprocessor directives are in if condition:

ifdef HAVE_CONFIG_H

include "config.h" / Here, a space is included between # and the command /

endif