One would like to have all the things in software, unless you require something which cannot be done in software. For example you cannot radiate software. Radiation electrodomestic waveform can be radiated, but not software. Therefore, there has got to be somewhere when you will convert a signal into an analogue waveform for transmission as well as for reception. This would imply that software control should be as close to antenna as possible, and therefore the diagram on these particular slide shows that it should have DSPs, which will give you a digital wayform and a transmission hardware which will convert it into a wayform and feed it to the antenna.

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