Editing Software-defined radio (section)

{{Short description|Radio communication system implemented in software}}
{{Multiplex techniques}}
{{Modulation techniques}}

'''Software-defined radio''' ('''SDR''') is a [[radio]] communication system where components that conventionally have been implemented in [[Analogue electronics|analog]] hardware (e.g. [[frequency mixer|mixer]]s, [[Filter (signal processing)|filter]]s, [[amplifier]]s, [[modulator]]s/[[demodulator]]s, [[detector (radio)|detector]]s, etc.) are instead implemented by means of software on a computer or [[embedded system]].<ref>{{Cite book|title=Software Defined Radio: Architectures, Systems and Functions|author=Markus Dillinger |author2=Kambiz Madani |author3=Nancy Alonistioti |page=xxxiii |publisher=Wiley & Sons|year= 2003|isbn=0-470-85164-3}}</ref>

A basic SDR system may consist of a [[personal computer|computer]] equipped with a [[sound card]], or other [[analog-to-digital converter]], preceded by some form of [[RF front end]]. Significant amounts of [[signal processing]] are handed over to the general-purpose processor, rather than being done in special-purpose hardware ([[electronic circuit]]s). Such a design produces a radio which can receive and transmit widely different radio protocols (sometimes referred to as waveforms) based solely on the software used.

Software radios have significant utility for the military and [[cell phone]] services, both of which must serve a wide variety of changing radio protocols in real time. In the long term, software-defined radios are expected by proponents like the [[Wireless Innovation Forum]] to become the dominant technology in radio communications. SDRs, along with [[software defined antenna]]s are the enablers of [[cognitive radio]].<ref>{{Cite book|last=Amaral|first=Cristiano|title=Guia Moderno do Radioescuta|publisher=Amazon|year=2021|isbn=978-65-00-20800-9|location=Brazil|page=333}}</ref>