Piyush Gupta

Packaging design considerations for mobile and Internet of things (IOT)

This talk will go over the various considerations that lead into final selection of a package for a particular application and end form factor. These aspects not only include cost and performance requirements but also include die constraints and OEM PCB choices. It will show an example that for different tier of phones; these trade-offs are different which leads to unique package selection choices. Than the talk will segue into system in package. Essentially highlighting how two unrelated trends of node shrinkage and end device form factor shrinkage are affecting package choices.

On the scaling of interference alignment under delay and power constraints

Future wireless standards such as 5G envision dense wireless networks with large number of simultaneously connected devices. In this context, interference management becomes critical in achieving high spectral efficiency. Orthogonal signaling, which limits the number of users utilizing the resource simultaneously, gives a sum-rate that remains constant with increasing number of users. An alternative approach called interference alignment promises a throughput that scales linearly with the number of users. However, this approach requires very high SNR or long time duration for sufficient channel variation, and therefore may not be feasible in real wireless systems. We explore ways to manage interference in large networks with delay and power constraints. Specifically, we devise an interference phase alignment strategy that combines precoding and scheduling without using power control to exploit the diversity inherent in a system with large number of users. We show that this scheme achieves a sum-rate that scales almost logarithmically with the number of users. We also show upper bounds on the sum-rate within the restricted class of single-symbol phase alignment schemes. Specifically, we prove that no scheme in this class can achieve better than logarithmic scaling of the sum-rate.