Generalized Degrees of Freedom of the Symmetric Gaussian $K$ User Interference Channel

Abstract

We characterize the generalized degrees of freedom of the $K$ user symmetric Gaussian interference channel where all desired links have the same signal-to-noise ratio (SNR) and all undesired links carrying interference have the same interference-to-noise ratio, $INR={SNR}^{\alpha }$. We find that the number of generalized degrees of freedom per user, $d(\alpha )$, does not depend on the number of users, so that the characterization is identical to the 2 user interference channel with the exception of a singularity at $\alpha =1$ where $d(1)=\frac{1}{K}$. The achievable schemes use multilevel coding with a nested lattice structure that opens the possibility that the sum of interfering signals can be decoded at a receiver even though the messages carried by the interfering signals are not decodable.

12 pages

References in corpus (2)

• A Deterministic Approach to Wireless Relay Networks
• Interference Alignment on the Deterministic Channel and Application to Fully Connected AWGN Interference Networks

Cited by in corpus (6)

• The Approximate Capacity of the Many-to-One and One-to-Many Gaussian Interference Channels
• On the Sum Capacity of A Class of Cyclically Symmetric Deterministic Interference Channels
• K-user Interference Channels: General Outer Bound and Sum-capacity for Certain Gaussian Channels
• Some "Goodness" Properties of LDA Lattices
• On the Symmetric $K$-user Interference Channels with Limited Feedback
• Relay Subset Selection in Wireless Networks Using Partial Decode-and-Forward Transmission