Adnan Yusuf wrote: > What is the difference between a software defined radio and a digital > radio? I am working on an SDR project and I keep getting asked this > question. > > > It depends what you mean by 'Digital Radio'...
One sort of Digital radio decodes digital encoded signals, like Digital Radio Mondiale, usually through a 'normal' radio (although you can use an SDR to receive DRM signals) and another type of Digital radio replaces AM or FM broadcast stations with DAB or Digital Audio Broadcasting see http://en.wikipedia.org/wiki/Digital_radio Software Defined Radio uses a different method of implementing the detection system, converting the incoming Radio Frequency signals into I and Q channels for processing in the software. The nearest to SDR is probably direct conversion radios where the incoming signal is mixed with another frequency that is very close (like a crystal on 3.560.0MHz mixed with an oncoming signal on 3.560.6MHz would give the sum and the difference of +/-600Hz, then you filter one out and just receive the other). But I guess you know how mixing and detection works if you are developing an SDR anyway... Dave (G0DJA)
