| A software defined radio is exactly what its name | | | | the rapid advance in electronics. SDR has been |
| suggests: a radio device whose operational | | | | deemed by many as the future of telecommunications, |
| characteristics are defined by its software rather than | | | | as most devices are expected to be SDRs in the |
| by its hardware. Components which are typically | | | | near future. |
| implemented in hardware such as filters, detectors, | | | | Current applications include the Joint Tactical Radio |
| modulators/demodulators, are instead implemented | | | | System (JTRS) of the US Army, as well as many |
| with software for general purpose processors which | | | | amateur radio or home use applications, replacing the, |
| can be executed on most personal computers. This | | | | much slower, computer sound cards which were used |
| provides the SDR huge flexibility with respect to | | | | earlier. Certain implementations, such as the USRP |
| operating frequencies, supported protocols, | | | | which we will discuss below, are also widely used for |
| waveforms etc meaning that virtually anything can be | | | | academic and industrial research programs, due to the |
| implemented. Practical implementations of such | | | | flexibility they provide in contrast to hardware |
| devices have only recently become feasible due to | | | | transceivers. |