Software Defined Radios – The Future is Now

摘要

A Software Defined Radio (SDR) is a radio in which all modulation and demodulationfunctions are defined, and therefore configurable, through software. This createstremendous flexibility to improve and adapt the capabilities of the radio over timewithout changing the hardware. The potential for amateur radio experimentation isvirtually limitless in terms of performance improvement and the introduction of newoperating modes.The idea for the SDR-1000 Software Defined Radio was formed about six years agowhile observing PSK31 running on a PC and sound card. Effectively, PSK31 uses thesound card and PC as a Digital Signal Processor (DSP) to perform modulation anddemodulation of a digital signal. It became clear that a phasing-type transceiver could bebuilt using the stereo inputs of the sound card for the in-phase (I) and quadrature (Q)signals. Four years and many hundreds of hours of study resulted a working transceiverthat was described in the four part QEX series, “A Software Defined Radio for theMasses.” Interest generated by the articles was so strong that a decision was made tobegin shipping the radio as a product in April of 2003. The articles, as well as completeinformation on the SDR-1000, are available on the FlexRadio Systems website atwww.flex-radio.com.