PARIS — Software radio company AeroStream Communications is demonstrating a low power, cost-effective radio solution for AM, FM and shortwave radios at the Embedded Systems Conference in San Francisco this week.
AeroStream developed the radio using Analog Devices Inc.'s Blackfin processor and low power analog front-end IF digitizer called the AD9874. The module, designed for radio operating from 500 kHz to 200 MHz, is focused on enabling superior sound quality reception of legacy analog radios, with additional features such as MP3 decoding, support for USB ports and display of song titles and artists.
Calling it “an antenna-to-speaker” solution, Don Moore, president of AeroStream Communications said that his company's module– integrated into a board “smaller than a credit card”– will be embedded into a major automobile in 2005. The same radio signal processor solution will also become available as a high quality, mid-range portable radio tuner on the consumer market, he added.
ADI's Blackfin, incorporated on the AeroStream's module, is responsible for everything from controlling display, managing push button functions to radio demodulation and audio reconstruction, said Moore. The Blackfin DSP configures the RF, tunes to a specific bandwidth on the fly, demodulates the signal, detects the audio codec, decodes it, takes out noise and reconstructs it into time frequency domain.
Meanwhile, the AD9874 integrates the majority of the analog signal chain and provides a digital output that interfaces directly to the Blackfin, reducing component count, board area, and cost, according to ADI.
With the new module, AeroStream's Moore estimated that 200 to 300 chip parts traditionally used in a legacy portable audio can be now reduced to about 50 chip parts including five major ICs, including the Blackfin DSP, DAC, flash, front-end IF digitizer, and PLL-mixer.
AeroStream's software-defined radio solution, designated as RSP-200, is the first radio solution to process shortwave radio digitally, said Bhaskar Banerjee, ADI's strategic business manager. Raw RF signals are digitized directly and the true mathematical operations for reception are performed, rather than the approximations performed by analog components.
“The DSP on the module looks up a shortwave station selection guide, automatically fine-tunes the signal– operating between 1.8MHz and 30MHz– and automatically synchronizes the carrier,” he added.
With a 500 kHz to 200 MHz frequency range, the AeroStream module can reconfigure itself for receiving signals from most emerging digital satellite and terrestrial radio broadcasts, according to Banerjee, provided that necessary audio codecs– some of them are proprietary to specific service providers– become available.
ADI is now working with an Israel-based company called Sonarics to develop a Digital Audio Broadcast (DAB) solution based on Blackfin, Banerjee said. As for Digital Radio Mondiale, which is a digital system for the AM broadcasting bands below 30 MHz, ADI is internally working on its solution for Blackfin.