Imagine an electronic gadget, like your cell phone, evolving into the next generation of communication devices through the use of radio technology. From the prospect of downloading software to adapt a cell phone into a video camera or MP3 player, to the idea that satellites could interact and share data directly by configuring themselves, the possibilities for SDR are without bound.
Researchers at NASA's Goddard Space Flight Center in Greenbelt, Md., are so enthusiastic about SDR that they have recently built an SDR test-bed - providing the necessary foundation for investigating SDR technologies and techniques. This test-bed allows for the rapid, low-cost development of communication and navigation algorithms that will be used in upcoming technology experiments, and eventually, in missions.
Software Defined Radio is a relatively new wireless technology based on the familiar radio technology that has been used for many years. Traditional Earth-based radio technology involves the transmission of a signal, typically "analog" speech or music, as electromagnetic waves using a single purpose radio transmitter. The electromagnetic waves travel through the air until they encounter a radio receiver that has been tuned to receive the right frequency. This receiver processes the signal and sends the result to a speaker. You then hear whatever was broadcast from the radio station. In SDR, the transmitter modulation is produced by a digital signal processor (a form of computer) to produce digital signals, the signals are then converted to "analog" and sent to the transmitter's antenna. The receiver uses a computer to recover the signal intelligence.
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