There was one thing in particular that 18-year-old George Frost missed when driving back in the year 1922 — listening to the radio. So he simply fitted a receiver into the door of his new Ford Model T, and thus invented the car radio. More than 80 years later, the car radio presents the automobile industry with much greater challenges: today, engineers have to provide a solution so that car radios are not only able to receive conventional analog signals, but digital radio too. Digital radio means better sound quality, a wider choice of stations, and services like weather and traffic information.
The multiple broadcasting standards for digital radio worldwide are a major challenge here — from Digital Radio Mondiale (DRM) or DRM+ through Digital Audio Broadcasting (DAB) or DAB+ to Terrestrial Digital Multimedia Broadcasting (T-DMB) and HD Radio. It does not look as though there could be any agreement on a single standard in the near future, because different countries have their own preferences: in the USA, HD Radio is standard, while Europe generally opts for DAB/DAB+/T-DMB, India listens to DRM, and Brazil cannot decide whether to go for DRM or HD Radio.
Fig 1: Around the world, listeners - and radio designers - are confronted with a confusing multitude of radio standards.
For the automobile industry as a global operator, that means producing a specific digital radio solution for each market, a degree of variety that costs time and money. Engineers are faced with evaluating, testing, and integrating different types of hardware so that drivers in different countries can simply do what George Frost wanted to do — listen to the radio in their car.
Software is more flexible than hardware
One solution can be seen in software-defined radio (SDR) together with multistandard processors plus flexible hardware accelerators. SDR is a radio system in which, in its pure form, typical components such as mixers, filters, modulators/demodulators, or detectors