What is software defined radio?

[velmith]

Please I need many useful links that explain software defined radio systems from the very basics to the details.

 

[n5ims]

Start here Software Defined Radio or here Software-defined radio - Wikipedia, the free encyclopedia and move through the links as necessary. These are currently on the market for ham use if you want to jump in quickly FlexRadio Systems - Software Defined Radios ::: Home Page

 

[joefitz232]

Software defined radio is a method of radio which attempts to do as much as possible in the digital realm, and the least amount in hardware. Ultimately they will digitize the spectrum the way a soundcard does, and use software to filter and demodulate the signals.

There's a decent intro to software defined radio and a dozen or so online quadrature sampling sdrs that you can click to listen to.

The filtering is very slick. I saw a demo of an AM filter that completely removes interference from off-frequency stations. Imagine listening to an AM broadcast buried between two stations playing music, clicking on the filter, and the interference goes away...