Complex DSP systems implementation involve many tradeoffs that can impact the quality of the final design to a great extent. Decisions that are made at a higher level of abstraction (system level rather than circuit level) have much higher impact on the final results.
Some of the research in this area deals with developing tools for rapid evaluation of these tradeoffs. One such approach is to focus only on the I/O behaviour of the system rather than the functionality, and construct simple models based on the IO behaviour that will help us predict various system parameters such as memory and buffer sizes.