Aquí lo explica :
Digital Radio Mondiale (DRM) is a new digital radio standard for the long-, medium- and short-wave ranges. The standard was formed by a consortium in co-operation with the International Telecommunication Union (ITU). The new system offers the radio stations and new service providers access to the multimedia age with small bit rates for large target areas and long distances. For more informaciónrmation 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 (assumed the receiver bandwidth 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++. The code runs under Microsoft Windows and Linux. Start of the project was June 2001.
Although this software is going to be 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.
If you just want to get the experience of DRM digital sound quality and expect a very stable and optimized receiver performance, we recommend to buy the commercial DRM Software Radio.