Approximate Capacity of Gaussian Relay Networks

TL;DR

This paper establishes a universal approximation of the capacity of Gaussian relay networks within a constant number of bits, independent of channel gains, based on an achievable rate close to the cut-set bound.

Contribution

It introduces a new achievable rate that approximates the capacity of Gaussian relay networks within a topology-dependent constant, regardless of channel parameters.

Findings

Achievable rate within a constant number of bits from the cut-set bound

Capacity characterized uniformly for all channel parameters

Constant depends only on network topology

Abstract

We present an achievable rate for general Gaussian relay networks. We show that the achievable rate is within a constant number of bits from the information-theoretic cut-set upper bound on the capacity of these networks. This constant depends on the topology of the network, but not the values of the channel gains. Therefore, we uniformly characterize the capacity of Gaussian relay networks within a constant number of bits, for all channel parameters.