I would rather think the solutions that will be successful will combine elements of some of those. Bier said he expects to see solutions that might incorporate a programmable processor alongside hardwired circuits and reconfigurable logic of some sort. To date, the development of software-defined radio has been confined to military applications, such as snooping or jamming communications, where cost and device size are not significant constraints. But semiconductor advances combined with the imminent arrival of 3G wireless systems are driving software-defined radio toward commercial markets. The earlier in the chain the data is converted, the more processing power is required.
Engineers see two approaches to that problem.
The other is to sample the incoming waveform right at the antenna. Right now we can't do either. The other problem is that even at baseband, the wide variety of standards, with different baseband processing, makes it a signal-processing nightmare in terms of flexibility, speed, power, cost, footprint and available processing horsepower. Until recently, the choice of approach was dictated by the type of system. Basestations, generally more tolerant of power and heat, might tap banks of DSPs, while handsets would employ ASICs for gains in speed and size, with lower power.