1 research outputs found
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 that no scheme using single symbol phase
alignment, which is asymmetric complex signaling restricted to a single complex
symbol, can achieve better than logarithmic scaling of the sum-rate.Comment: Shorter version to appear in ISIT 201