Digital Radio Mondiale (DRM) For Car Radios

Fraunhofer IIS presented the first DRM chip design for car radios. This car radio solution will enable drivers to select their preferred radio program from hundreds of different radio stations. However, it is something more than purely listening to favorite music: the new radio formats offer multilingual support to ethnic news or talk programs. In this way, drivers will get local news or may listen to programs in foreign languages – at any time and any place.

With the international CES exhibition in Las Vegas on January 6 – 9, 2005, the vision of Digital Radio Mondiale DRM car radios got one step closer to reality. Based on Philips‘ ”SAF7730” digital car radio platform, Fraunhofer Institute for Integrated Circuits IIS presented the first DRM implementation that seamlessly fits into today’s car radios. For the OEM, upgrading to the international DRM standard is just a matter of inserting a ”DRM module” into an existing connector slot. Initially, the ”DRM module” upgrade allows to differentiate products with minimum investment, risk and time to market. In the next stage, the evolving road maps with fully integrated ”DRM car radio chip sets” will lower the system cost further, completely inline with the requirements of the mass market.

The DRM standard applies the latest advanced audio coding algorithms for music and speech transmission – to provide FMlike sound quality at very limited bandwidth. DRM programs are digitally transmitted and highly compressed. Therefore, they may be stored on-the-fly in the car radio’s memory, to build up a personal music collection. In addition, DRM programs carry other types of multimedia content and information, including headline news or traffic and tourist information. This data is transmitted in the background and will be immediately available after one gets into the vehicle.

The technical solution presented for DRM car radios uses Philips’ ”SAF7730“ digital car radio platform. It is equipped with an integrated Philips tuner „TEF6730“ capable of digital AM and FM decoding and sound processing. The DRM decoder, based on the algorithms of the well known “Fraunhofer DRM Software Radio“, is integrated in hardware on a FPGA prototype. The decoding of data services runs on an ARM9 processor on the same prototype board. This processor is also used for audio and speech decoding, employing the decoder libraries from Coding Technologies.

Broadcasters will benefit from this Digital Radio Mondiale DRM solution for car radios: DRM provides broadcasters with additional spectrum in the AM bands. The fact that it is easy and cost-efficient to bring DRM programs on air enables established stations to broaden their coverage area. Moreover, it opens opportunities to newcomers and innovative content providers to bring in more program diversity to reach their specific audiences.