MIMO Gaussian State-Dependent Channels with a State-Cognitive Helper

Abstract

We consider the problem of channel coding over multiterminal state-dependent channels in which neither transmitters nor receivers but only a helper node has a non-causal knowledge of the state. Such channel models arise in many emerging communication schemes. We start by investigating the parallel state-dependent channel with the same but differently scaled state corrupting the receivers. A cognitive helper knows the state in a non-causal manner and wishes to mitigate the interference that impacts the transmission between two transmit–receive pairs. Outer and inner bounds are derived. In our analysis, the channel parameters are partitioned into various cases, and segments on the capacity region boundary are characterized for each case. Furthermore, we show that for a particular set of channel parameters, the capacity region is entirely characterized. In the second part of this work, we address a similar scenario, but now each channel is corrupted by an independent state. We derive an inner bound using a coding scheme that integrates single-bin Gel’fand–Pinsker coding and Marton’s coding for the broadcast channel. We also derive an outer bound and further partition the channel parameters into several cases for which parts of the capacity region boundary are characterized.

Parallel Gaussian Channels Corrupted by Independent States With a State-Cognitive Helper

“…We have also demonstrated our results using numerical simulation and have shown that our achievability scheme outperforms time-sharing that was shown to be optimal for the infinite state power regime in [11]. In our previous work [10], a model with same but differently scaled states was considered. These two models represent a special case of more general scenario with correlated states, our results in both studies imply that as the states are more correlated than it easier to mitigate the interference.…”

“…Our previous work [10] studied a situation where each channel is corrupted by same but differently scaled state was considered. In [11] a similar setup was considered but with infinite state power.…”

A general achievable rate region and two certain capacity regions for Slepian–Wolf multiple‐access relay channel with non‐causal side information at one encoder

“…The capacity inner bound for DM-MARC with non-causal SI known at the relay and its extension to Gaussian case was studied in [44]. Also, the MARC in the presence of SI at both cooperating encoders and the MARC with relay-source feedback, and the transmission of analog information over MARC in [45][46][47], respectively, and the MIMO state-dependent channel in which only the helper node has a non-causal knowledge of the state in [48] were studied.…”