Bounds on the capacity regions of half-duplex Gaussian MIMO relay channels
Lennart Gerdes, Maximilian Riemensberger, Wolfgang Utschick · EURASIP Journal on Advances in Signal Processing · 2013
This article considers uni-and bidirectional communication in the half-duplex Gaussian multiple-input multiple-output (MIMO) relay channel.Assuming perfect channel state information at all nodes and the use of time division duplex communications protocol to separate transmissions and receptions at all nodes, we propose a dual decomposition approach to efficiently determine upper and lower bounds on the capacity and the capacity region of the half-duplex relay channel and the restricted half-duplex two-way relay channel, respectively.Our approach allows to quantify the fundamental limits of the considered relay networks, and the obtained results may serve as benchmarks when studying different and/or suboptimal relay strategies or the impact of channel estimation errors.Furthermore, we discuss how our dual decomposition approach may be used for designing optimal resource allocation protocols.