Deterministic Capacity of MIMO Relay Networks

TL;DR

This paper investigates the deterministic capacity of MIMO relay networks in the low SNR regime, providing a method to derive capacity bounds without complex distribution optimization.

Contribution

It introduces a novel approach to determine deterministic capacity in MIMO relay networks at low SNR by deriving single-letter upper bounds and analyzing their limits.

Findings

Deterministic capacity can be characterized as SNR approaches zero.

Single-letter upper bounds are effective in low SNR analysis.

The method circumvents the need for optimizing mutual information distributions.

Abstract

The deterministic capacity of a relay network is the capacity of a network when relays are restricted to transmitting \emph{reliable} information, that is, (asymptotically) deterministic function of the source message. In this paper it is shown that the deterministic capacity of a number of MIMO relay networks can be found in the low power regime where $\SNR\to0$. This is accomplished through deriving single letter upper bounds and finding the limit of these as $\SNR\to0$. The advantage of this technique is that it overcomes the difficulty of finding optimum distributions for mutual information.