2015/01/26 by Song-Nam Hong, Hong, Song-Nam, Ivana Maric +5
Computer Science · Mathematics · #FOS: Computer and information sciences #Information Theory (cs.IT) #cs.IT #math.IT
paper · pdf · doi:10.48550/arxiv.1501.06440
To be presented at ISIT 2015
arxiv created 2015/04/23 · arxiv updated 2015/04/24
We study a multihop "virtual" full-duplex relay channel as a special case of a general multiple multicast relay network. For such channel, quantize-map-and-forward (QMF) (or noisy network coding (NNC)) achieves the cut-set upper bound within a constant gap where the gap grows \em linearly with the number of relay stages K. However, this gap may not be negligible for the systems with multihop transmissions (i.e., a wireless backhaul operating at higher frequencies). We have recently attained an improved result to the capacity scaling where the gap grows \em logarithmically as logK, by using an optimal quantization at relays and by exploiting relays' messages (decoded in the previous time slot) as side-information. In this paper, we further improve the performance of this network by presenting a mixed scheme where each relay can perform either decode-and-forward (DF) or QMF with possibly rate-splitting. We derive the achievable rate and show that the proposed scheme outperforms the QMF-optimized scheme. Furthermore, we demonstrate that this performance improvement increases with K.