Software-defined Radio - History

History

The term "software radio" was coined in 1984 by a team at the Garland Texas Division of E-Systems Inc. (now Raytheon). A classified, yet fairly well known, 'Software Radio Proof-of-Concept' laboratory was developed at E-Systems that popularized Software Radio within various government agencies. This 1984 Software Radio was a digital baseband receiver that provided programmable interference cancellation and demodulation for broadband signals, typically with thousands of adaptive filter taps, using multiple array processors accessing shared memory.

Perhaps the first software-defined radio transceiver was designed and implemented by Peter Hoeher and Helmuth Lang at the German Aerospace Research Establishment (DLR, formerly DFVLR) in Oberpfaffenhofen, Germany, in 1988. Both transmitter and receiver of an adaptive digital satellite modem were implemented according to the principles of software-defined radio, and a flexible hardware periphery was proposed.

The term "software defined radio" was coined in 1991 by Joseph Mitola, who published the first paper on the topic in 1992. Though the concept was first proposed in 1991, software-defined radios have their origins in the defense sector since the late 1970s in both the U.S. and Europe (for example, Walter Tuttlebee described a VLF radio that used an ADC and an 8085 microprocessor). One of the first public software radio initiatives was a U.S. military project named SpeakEasy. The primary goal of the SpeakEasy project was to use programmable processing to emulate more than 10 existing military radios, operating in frequency bands between 2 and 2000 MHz. Further, another design goal was to be able to easily incorporate new coding and modulation standards in the future, so that military communications can keep pace with advances in coding and modulation techniques.