Digital AM Joins FM In Receiver

Digital audio broadcast (DAB) receivers are growing in popularity around the world, enabling listeners to enjoy digital fidelity along with a host of add-on data features. This technology may get another boost from digital long-wave (LW), medium-wave (MW), and short-wave (SW) broadcasts using the Digital Radio Mondiale (DRM) standard. RadioScape's RS500 module makes such receivers possible and affordable.

With the recently approved DRM standard and the RS500, OEMs can build highly integrated multistandard digital radio receivers that can pick up FM with RDS, as well as amplitude-modulated LW, MW, and SW broadcasts. DRM is the only global standard for digitizing the broadcast content in the AM LW, MW, and SW bands. Over 20 broadcasters already deliver DRM content around the globe. (For more about DRM, go to www.drm.org.)

Based on the company's software-defined digital radio and radiOS operating-system (OS) architecture, the RS500 packs a TMS320CDRM350 DSP from Texas Instruments to handle all the baseband processing. The DRM/DAB-capable module can reuse existing application software previously developed for the RS300L DAB/FM receiver module, which RadioScape released last year.

In addition to new system designs, the RS500 can serve as a drop-in upgrade for RS300L systems. As a result, it can immediately support RS300L module features such as pause, rewind, and recording to a multimedia memory card. Also, it can display and use electronic program guide (EPG) data.

The DSP chip executes the DRM and DAB baseband software stacks, while the radiOS extends the DSP's basic capabilities. The OS can seamlessly manage uploads of the appropriate software stack and/or applications to change functionality to suit the requirements of the moment. This will significantly improve the user experience, masking transitions between different broadcast standards by automatically listing all services alphabetically regardless of the transmission type users select by content. This avoids the need for manual band-switching.

Samples of the RS500 modules will be available in August. The company estimates that a full receiver based on the module could be offered for less than $250, or about one-quarter the price of existing DRM receivers.