Distributed Khatri-Rao space-time coding and decoding for cooperative networks

Khatri-Rao space-time (KRST) coding is an efficient scheme proposed in the last decade for multi-antenna communication systems. The decoding process results on a tensor decomposition with interesting blind decodability properties. In this paper, we consider its extension to cooperative networks where each node has a single antenna. For this purpose, we propose a distributed KRST coding and decoding technique. The proposed distributed decoding scheme is based on average consensus embedded in an alternating least squares (ALS) algorithm. Unlike standard consensus algorithms where consensus is reached asymptotically, we derive closed form solutions allowing to reach the consensus in a finite number of iterations upper-bounded by the number of collaborating nodes. The performance of the proposed method is evaluated by means of simulations.